January 1991 - December 1993
Quick Bibliography Series: QB 94-06 (Updates QB 92-69)
337 citations from AGRICOLA
Joe Makuch and Bonnie Emmert
Water Quality Information Center
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Simulation Models, GIS and Nonpoint-Source Pollution
1 NAL Call. No.: 56.8 SO3
An accurate and numerically stable model for one-dimensional
solute transport in soils.
Moldrup, P.; Yamaguchi, T.; Hansen, J.A.; Rolston, D.E.
Baltimore, Md. : Williams & Wilkins; 1992 Apr.
Soil science v. 153 (4): p. 261-273; 1992 Apr. Includes
references.
Language: English
Descriptors: Soil solution; Solutes; Transport processes;
Simulation models; Mathematical models; Soil water movement;
Convection; Dispersion; Comparisons; Accuracy; Soil testing;
Soil water content; Loam soils
2 NAL Call. No.: QH540.N3
Adsorption-desorption methodologies and selected estimation
techniques for transport-modeling parameters.
Roy, W.R.
Berlin, W. Ger. : Springer-Verlag; 1993.
NATO ASI series : Series G : Ecological sciences v. 32: p.
169-188; 1993. In the series analytic: Migration and fate of
pollutants in soils and subsoils / edited by D. Petruzzelli
and F.G. Helfferich. Proceedings of the NATO Advanced Study
Institute, May 24-June 5, 1992, Maratea, Italy. Includes
references.
Language: English
Descriptors: Soil pollution; Pollutants; Adsorption;
Desorption; Transport processes; Computer simulation; Vapor;
Organic compounds; Volatilization; Groundwater pollution;
Trichloroethylene; Microbial degradation
3 NAL Call. No.: HD1773.A2N6
Aggregate analysis of site-specific pollution problems: the
case of groundwater contamination from agriculture.
Opaluch, J.J.; Segerson, K.
Morgantown, W.Va. : The Northeastern Agricultural and Resource
Economics Association; 1991 Apr.
Northeastern journal of agricultural and resource economics v.
20 (1): p. 83-97; 1991 Apr. Paper submitted in response to
call for papers on the theme "The Effects of Agricultural
Production on Environmental Quality.". Includes references.
Language: English
Descriptors: Groundwater; Contamination; Water pollution;
Agricultural sector; Agricultural policy; Microeconomic
analysis; Aggregate data; Site factors; Spatial distribution;
Information systems; Mathematical models
4 NAL Call. No.: S900.R39
Analysing water quality policy using microeconomic models of
production practices and biophysical flow models of
environmental processes. Weaver, R.D.; Harper, J.K.
London : Harwood Academic Publishers; 1993.
Resource management and optimization v. 9 (2): p. 95-105;
1993. Includes references.
Language: English
Descriptors: U.S.A.; Water quality; Water policy;
Microeconomics; Technology; Environmental factors;
Mathematical models
5 NAL Call. No.: 292.8 W295
An analytical solution for one-dimensional transport in porous
media with an exponential dispersion function.
Yates, S.R.
Washington, D.C. : American Geophysical Union; 1992 Aug.
Water resources research v. 28 (8): p. 2149-2154; 1992 Aug.
Includes references.
Language: English
Descriptors: Transport processes; Solutes; Hydrodynamic
dispersion; Subsurface layers; Equations; Mathematical models
Abstract: An analytical solution describing the transport of
dissolved substances in heterogeneous porous media with an
asymptotic distance-dependent dispersion relationship has been
developed. The solution has a dispersion function which is
linear near the origin (i.e., for short travel distances) and
approaches an asymptotic value as the travel distance becomes
infinite. This solution can be used to characterize
differences in the transport process relative to both the
classical convection-dispersion equation which assumes that
the hydrodynamic dispersion in the porous medium remains
constant and a dispersion solution which has a strictly linear
dispersion function. The form of the hydrodynamic dispersion
function used in the analytical solution is D(x) = alpha(x)
average pore water velocity + D(diff), where a(x) = a L[1 -e(-
bx/L)]. The proposed model may provide an alternate means for
obtaining a description of the transport of solutes in
heterogeneous porous media, when the scale dependence of the
dispersion relationship follows the behavior given by
alpha(x). The overall behavior of the model is illustrated by
several examples for constant concentration and flux boundary
conditions.
6 NAL Call. No.: 56.9 SO3
Analytical solution of solute diffusion and biodegradation in
spherical aggregates.
Priesack, E.
Madison, Wis. : The Society; 1991 Sep.
Soil Science Society of America journal v. 55 (5): p.
1227-1230; 1991 Sep. Includes references.
Language: English
Descriptors: Microbial degradation; Soil flora; Organic
compounds; Solutes; Diffusion; Soil solution; Aggregates;
Spatial distribution; Mathematical models; Soil pore system;
Pores; Transport processes; Movement in soil; Diffusivity;
Growth rate; Adsorption; Biomass; Substrates
Abstract: Microbial degradation and transformation of
substances in soils plays a crucial role ii the nutrient
turnover of ecosystems. To quantify these processes, a
mathematical description is needed. For this purpose, an
analytical solution to a model of solute diffusion and
biodegradation in soil aggregates was developed. The model is
a first approach toward understanding the influence of
geometric arrangement of microorganisms and substrates in
structured soils. These soils are considered to consist of
uniformly sized and shaped aggregates surrounded by surface
films of the soil solution. The model simulates transient
diffusion of finite substrate amounts from the surface films
into spherical aggregates. Biodegradation is considered for
the special case of unlimited microbial growth, and adsorption
is assumed to follow a linear Freundlich isotherm. The system
is represented by a composite sphere, the outer sphere being
the solution film and the inner sphere representing the soil
aggregate. The diffusion equations are solved by Laplace
transformation. The model solution gives a direct relationship
between the initial substrate and biomass concentrations, the
diffusion coefficient, the specific growth rate, and the
adsorption coefficient. Good agreement between this closed
form solution and numerical solutions is obtained for
diffusion with and without biodegradation. Since the substrate
is exhausted by organisms close to the surface, the centers of
large aggregates are not reached by the diffusing substrate.
These unaffected centers become lager as the growth rate is
higher, the diffusion constant is lower, and adsorption of the
substrate is stronger.
7 NAL Call. No.: 292.8 W295
Analytical solutions for solute transport in three-dimensional
semi-infinite porous media.
Leij, F.J.; Skaggs, T.H.; Van Genuchten, M.T.
Washington, D.C. : American Geophysical Union; 1991 Oct.
Water resources research v. 27 (10): p. 2719-2733; 1991 Oct.
Includes references.
Language: English
Descriptors: Transport processes; Solutes; Flow; Mathematical
models; Prediction
Abstract: This paper presents several analytical solutions
for three-dimensional solute transport in semi-infinite porous
media with unidirectional flow using first-type (or
concentration) and third-type (or flux) boundary conditions at
the inlet location of the medium. The solutions may be used
for predicting solute concentrations in homogeneous media,
verification of more comprehensive numerical models, and
laboratory or field determination of solute transport
parameters. The transport equation incorporates terms
accounting for advection, dispersion, zero-order production,
and first-order decay. General solutions were derived for an
arbitrary initial distribution and solute input with the help
of Laplace, Fourier, and Hankel transforms. Specific solutions
are presented for rectangular and circular solute inflow
regions, as well as for solutes initially present in the form
of parallelepipedal or cylindrical regions of the medium. The
solutions were mathematically verified against simplified
analytical solutions. Examples of concentration profiles are
presented for several solute transport parameters using both
first- and third-type boundary conditions. A mass balance
constraint is defined based on a prescribed solute influx; the
third-type condition is shown to conserve mass whereas the
first-type condition was found to always overestimate resident
solute concentrations in the medium.
8 NAL Call. No.: 292.8 W295
Applicability of the steady state flow assumption for solute
advection in field soils.
Destouni, G.
Washington, D.C. : American Geophysical Union; 1991 Aug.
Water resources research v. 27 (8): p. 2129-2140; 1991 Aug.
Includes references.
Language: English
Descriptors: Agricultural soils; Solutes; Transport processes;
Transient flow; Soil water movement; Soil texture; Soil depth;
Plant water relations; Simulation models
Abstract: A comparison between solute travel times predicted
by a transient and a steady state flow model is made. Data for
five different soil profiles with detailed measurements of
their hydraulic properties and their variation with depth are
used. Daily measurements of meteorological data are used as
input parameters in the transient simulations that include
snow and frost dynamics, interception of precipitation, and
evapotranspiration. The parameters of the steady state flow
model are related to the measured soil properties and the
hydrological characteristics of each transient simulation.
Furthermore, the influence of solute injection time on the
predicted travel time is analyzed, and the effect of root
water uptake on the applicability, of the steady state flow
assumption for solute advection is investigated. The results
indicate that the steady, state flow model may provide
estimates of the mean solute advection that are compatible
with those of the transient flow model. The constant rate of
recharge in the steady state flow, model should then be
interpreted as the average annual effective infiltration
(i.e., infiltration minus actual evapotranspiration). When
root water uptake is accounted for, an arithmetic depth-
averaging of the soil parameters appears to yield steady state
estimates of arrival time that are closest to the transient
predictions. When root water uptake is neglected, a harmonic
depth-averaging of the soil parameters provides the best
steady state results. The discrepancy between the arrival
times predicted with the two flow models decreases with the
travel distance from the soil surface.
9 NAL Call. No.: 100 G29So no.372
Application and enhancement of hydrologic/water quality
models.. S-211 final report
Thomas, Daniel L.; Shirmohammadi, Adel,_1952-; Engel, Bernard
A. Tifton, Ga. : Biological and Agricultural Engineering Dept.
: University of Georgia-Coastal Plain Experiment Station,;
1992.
xi, 114 p. : ill. ; 28 cm. (Southern cooperative series
bulletin ; no. 372). Running title: S-211 final report. June,
1992. Includes bibliographical references.
Language: English; English
Descriptors: Hydrology; Water quality
10 NAL Call. No.: SB951.P47
Application and validation of pesticide leaching models.
Klein, M.
Essex : Elsevier Applied Science Publishers; 1991.
Pesticide science v. 31 (3): p. 389-398; 1991. Includes
references.
Language: English
Descriptors: German federal republic; Bentazone; Cloethocarb;
Simulation models; Environmental factors; Leaching;
Lysimeters; Pesticide residues; Soil properties; Climatic
factors
Abstract: Two lysimeter studies with the pesticides
cloethocarb and bentazone were used to validate a modified
version of the computer model SESOIL (Seasonal Soil
Compartment Model), developed by Bonazountas and Wagner and to
transfer the results of the lysimeter study to another climate
scenario. For cloethocarb, an experimental insecticide without
marked mobility in the soil, as indicated by the lysimeter
study, the simulations were in excellent agreement with the
lysimeter study. Calculations for bentazone revealed higher
leaching than found in the lysimeter study. This discrepancy
was resolved by a more careful and realistic inclusion of
sorption in the lysimeter soil into the simulation model.
11 NAL Call. No.: 292.8 J82
An application of a physically based semi-distributed model to
the Balquhidder catchments.
Robson, A.J.; Whitehead, P.G.; Johnson, R.C.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1993 May15.
Journal of hydrology v. 145 (3/4): p. 357-370; 1993 May15.
Special Issue: The Balquhidder Catchment and Process Studies /
edited by P.G. Whitehead and I.R. Calder. Includes
references.
Language: English
Descriptors: Scotland; Watersheds; Simulation models;
Catchment hydrology; Rain; Runoff; Flow
Abstract: A physically based semi-distributed model,
TOPMODEL, is applied to the two catchments at Balquhidder. The
model uses a topographic index which highlights hydrologically
significant areas within the catchments. The model is used to
simulate runoff and to compare the behaviour of the two
catchments. The results indicate that a large proportion of
stream water is generated from saturated contributing areas
(source areas); the Monachyle has higher contributions of
water of this type. The results may also indicate that the
hydrology of the Monachyle catchment has changed following
agricultural improvement by increased drainage; a damped
subsurface response is observed.
12 NAL Call. No.: QA76.76.E95A5
Application of case-based reasoning concepts to the WEPP soil
erosion model. Meyer, C.R.; Flanagan, D.C.
Moscow, Idaho : AI Applications; 1992.
AI applications v. 6 (3): p. 63-71; 1992. Includes
references.
Language: English
Descriptors: U.S.A.; Water erosion; Prediction; Simulation
models; Information retrieval; Usda; Improvement; Management;
Practice; Information storage; Data banks; Program
development; Computer techniques
13 NAL Call. No.: 56.9 SO3
Applications of a laser scanner to quantify soil
microtopography. Huang, C.H.; Bradford, J.M.
Madison, Wis. : The Society; 1992 Jan.
Soil Science Society of America journal v. 56 (1): p. 14-21;
1992 Jan. Includes references.
Language: English
Descriptors: North Carolina; Hapludults; Inceptisols; Surface
roughness; Measurement; Quantitative techniques; Surface
layers; Topography; Height; Spatial variation; Mathematical
models; Mathematics; Transport processes; Soil boundaries;
Artificial precipitation; Tillage; Interrill erosion; Soil
water content; Size; Lasers
Abstract: Many transport processes on or across the soil
surface boundary are controlled by surface microtopography, or
roughness. How roughness affects the transport process depends
on the length scale of the process. The most commonly used
method of expressing soil surface roughness, the roughness
length or random roughness, is constrained by the measurement
technique and does not embody the concept of scale. The
structural function, or variogram, plotted on a log-log scale
was used in this study to express the surface roughness at
different scales. With the aid of a laser scanner, surface
topography was measured down to 0.5-mm grid spacing. Data
collected from a variety of surface conditions showed that
soil roughness can be quantified by a combination of fractal
and Markov-Gaussian processes at different scales. Potential
applications of the roughness quantification were also
discussed.
14 NAL Call. No.: TD426.J68
An approach to estimating uncertainties in modeling transport
of solutes through soils.
Zhang, H.; Haan, C.T.; Nofziger, D.L.
Amsterdam : Elsevier; 1993 Feb.
Journal of contaminant hydrology v. 12 (1/2): p. 35-50; 1993
Feb. Includes references.
Language: English
Descriptors: Soil pollution; Groundwater pollution;
Pollutants; Chemicals; Solutes; Movement in soil; Uncertainty;
Rain; Variation; Prediction; Simulation models
15 NAL Call. No.: 292.8 W295
Approximate analytical solution for soil chemical transfer to
runoff: a modified boundary condition.
Wallach, R.
Washington, D.C. : American Geophysical Union; 1993 May.
Water resources research v. 29 (5): p. 1467-1474; 1993 May.
Includes references.
Language: English
Descriptors: Agricultural chemicals; Soil solution; Surface
water; Runoff water; Overland flow; Boundaries; Transport
processes; Equations; Mathematical models; Comparisons
Abstract: Two mass balance equations were used to model the
transfer of dissolved chemicals from the soil solution to the
surface runoff water and the transport of these chemicals to
the field outlet. One mass balance equation was written for
chemicals dissolved in the overland water, the other for
chemicals within the soil profile. Chemical input into the
surface water (upper boundary condition) was expressed as a
rate-limited convective mass transfer, depending on both soil
surface and runoff concentrations. Isolating a slow and fast
time scale and scaling the mass balance equations to the slow
one yielded a parameter, epsilon, which multiplies the time
derivative of the mass balance equation written for overland
flow. In most cases epsilon << 1, providing a singular
perturbation problem that was solved by using the method of
matched asymptotic expansion. The approximate solution,
uniformly valid over the entire domain, was made up of two
terms: a leading-order solution and a first-order solution,
the latter of which was relatively small, even for epsilon =
O(1). The leading-order solution was compared with that for a
simpler case, in which the convective mass transfer (upper
boundary condition) depends only on the soil surface
concentration. The comparison indicated those limited cases to
which the simpler boundary condition can be applied resulting
in a very small error. Although it is not possible to get a
strictly analytical solution for a problem involving a
modified upper boundary condition, the approximate analytical
solution is easily obtained.
16 NAL Call. No.: 292.9 AM34
Assessing ground water pollution potential from nitrogen
fertilizer using a geographic information system.
Halliday, S.L.; Wolfe, M.L.
Bethesda, Md. : American Water Resources Association; 1991
Mar. Water resources bulletin v. 27 (2): p. 237-245; 1991 Mar.
Includes references.
Language: English
Descriptors: Texas; Groundwater pollution; Nitrogen
fertilizers; Pollutants; Susceptibility; Expert systems
Abstract: A geographic information system (GRASS 3.1) was
used to correlate the availability of nitrogen fertilizer with
the susceptibility of ground water to pollution in Texas to
identify potential ground water quality problems. An
agricultural pollution susceptibility map, produced by the
Texas Water Commission using the DRASTIC methodology, was
combined with information on cropped areas, recommended
nitrogen fertilizer application rates, and aquifer outcrops. A
Nitrogen Fertilizer Pollution Potential Index was generated,
identifying 24 percent or Texas within the high pollution
potential category. An analysis of the susceptibility of major
aquifer outcrops to potential pollution from nitrogen
fertilizer indicated that 34 percent of the outcrop areas fall
in the high pollution potential range. It is proposed that
correlating the availability of a pollutant with an assessment
of the susceptibility of ground water to pollution yields a
more accurate screening tool for identifying potential
pollution problems than considering susceptibility alone.
17 NAL Call. No.: S542.A8A34
Assessment and alleviation of the impact of runoff and erosion
on crop production.
Okwach, G.E.; Williams, J.; Wambua, J.
Canberra : Australian Centre for International Agricultural
Research; 1992. ACIAR proceedings (41): p. 72-82; 1992. In
the series analytic: A search for strategies for sustainable
dryland cropping in semi-arid eastern Kenya / edited by M.E.
Probert. Paper presented at a symposium held Dec 10-11, 1990,
Nairobi, Kenya. Includes references.
Language: English
Descriptors: Kenya; Runoff; Erosion; Soil fertility; Tillage;
Mulches; Soil conservation; Semiarid zones; Simulation models
18 NAL Call. No.: 292.8 J82
An assessment of the dynamic response characteristics of
streamflow in the Balquhidder catchments.
Jakeman, A.J.; Littlewood, I.G.; Whitehead, P.G.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1993 May15.
Journal of hydrology v. 145 (3/4): p. 337-355; 1993 May15.
Special Issue: The Balquhidder Catchment and Process Studies /
edited by P.G. Whitehead and I.R. Calder. Includes
references.
Language: English
Descriptors: Scotland; Watersheds; Stream flow; Catchment
hydrology; Clearcutting; Afforestation; Rain; Runoff;
Simulation models
Abstract: The method of rainfall-runoff modelling and
hydrograph separation developed in an earlier paper is applied
to the Kirkton and Monachyle catchments situated near
Balquhidder, Scotland. Using daily rainfall and streamflow
data, natural differences between the quick and slow flow
responses for the Kirkton and Monachyle catchments are
quantified, and an attempt is made to detect the impact of
land-use changes on these natural regimes (clear-felling in
part of the Kirkton and drainage ditching and conifer planting
in part of the Monachyle). Dynamic response characteristics
for the quick and slow flow components are defined in terms of
time constants, relative throughput volumes and unit
hydrograph peaks. These response characteristics are estimated
and compared for annual periods before and after the land-use
changes. For both the Kirkton and Monachyle, the effects of
the land-use changes (affecting part of each catchment) on the
hydrological response are not detectable at the catchment
outlets. The interannual variation of the dynamic response
characteristics falls within the inherent uncertainty expected
if no land-use changes had occurred.
19 NAL Call. No.: aS21.A8U5/ARS
Basin scale water quality model.
Arnold, J.G.
Washington, D.C. : The Service; 1993.
Reprints - U.S. Department of Agriculture, Agricultural
Research Service [512]: 9 p.; 1993. Indexed from reprint:
Proceedings of the CREAMS and GLEAMS Conference. p. 192-200.
Includes references.
Language: English
Descriptors: Catchment hydrology; Simulation models; Water
quality; Climatic factors; Geological sedimentation; Runoff;
Agricultural chemicals
20 NAL Call. No.: S612.I756
Best management of pesticide--furrow irrigation systems.
Ranjha, A.Y.; Peralta, R.C.; Requena, A.M.; Deer, H.M.;
Ehteshami, M.; Hill, R.W.; Walker, W.R.
Berlin, W. Ger. : Springer International; 1992.
Irrigation science v. 13 (1): p. 9-14; 1992. Includes
references.
Language: English
Descriptors: Utah; Furrow irrigation; Design; Simulation
models; Pesticides; Leaching; Losses from soil systems; Water
management; Groundwater pollution; Soil texture
Abstract: Effects of furrow irrigation designs, water
management practices (irrigation scheduling, etc.), soil types
and pesticide parameters on pesticide leaching were simulated.
A hydraulic kinematic-wave irrigation model was used to
estimate water infiltration for alternative furrow lengths and
inflow rates. A one-dimensional simulation model then
simulated the movement of pesticides through soils following
furrow irrigation. Potential ground-water contamination by
pesticides can be reduced by an integrated use of the best
management practices (BMPs) such as careful selection and use
of pesticides, efficient furrow irrigation designs and
improved water management techniques (irrigation scheduling,
etc.). Procedures for designing an appropriate furrow
irrigation system for a particular site and pesticide, and
selecting pesticides for a particular site, crop and furrow
irrigation system are illustrated. These procedures are being
used to develop decision support computer models for
developing different BMPs for pesticide-agricultural
management decisions.
21 NAL Call. No.: GB701.W375 no.91-4055
Calibration, verification, and use of a steady-state stream
water-quality model for Monument and Fountain Creeks, east-
central Colorado. Kuhn, Gerhard
Pikes Peak Area Council of Governments, Geological Survey
(U.S.) Denver, CO : U.S. Dept. of the Interior, U.S.
Geological Survey : Books and Open-File Reports Section
[distributor],; 1991.
vii, 149 p. : ill. ; 28 cm. (Water-resources investigations
report ; 91-4055). Includes bibliographical references (p.
139-142).
Language: English
Descriptors: Water quality
22 NAL Call. No.: 290.9 AM32T
Characterization of macropore transport studied with the ARS
root zone water quality model.
Ahuja, L.R.; DeCoursey, D.G.; Barnes, B.B.; Rojas, K.W.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1993 Mar. Transactions of the ASAE v. 36 (2): p.
369-380; 1993 Mar. Includes references.
Language: English
Descriptors: Macropores; Movement in soil; Root zone flux;
Soil water; Water flow; Fertilizers; Pesticides; Simulation
models
Abstract: The ARS Root Zone Water Quality Model components
dealing with preferential water and chemical transport are
presented and used to study macropore flow and transport in a
silty clay loam soil. Macroporosity of the soil was assumed to
be 0.05% by volume, half of which was continuous and the rest
discontinuous. Two rainfall sequences with two initial soil
water contents, evaporation versus transpiration, macropore
radius ranging from 1.0 to 0.125 mm, and three different
chemicals were evaluated. Over a five-week period, weekly
rainfall of 25.4 mm in one hour, with soil water
redistribution and evaporation or transpiration occurring
between storms, generated no macropore flow when the soil was
initially dry (-1500 kPa). A slight amount of macropore flow
was generated under the same rainfall when the soil was
initially wet (-33 kPa). Doubling the weekly rainfall amount
and intensity generated macropore flow varying between 30 to
50% of rainfall depending on initial and boundary conditions.
Chemicals transported with this flow were 0.05 to 8% of the
surface-applied amount, depending on conditions and type of
chemical. A moderately adsorbed chemical (Atrazine) was the
most susceptible to macropore transport, followed in order by
a strongly adsorbed chemical (Prometryn), and a mobile
chemical (Nitrate). The flow entering the macropores was
partially absorbed by soil at progressively deeper depths; it
increased the water content of the root zone, and created a
tail of low concentrations in the soil chemical content
distributions. The macropore size had very little effect on
macropore flow and transport, but the smallest size pores
retarded the downward chemical movement by wall adsorption a
little more than the largest size pores. Surface evaporation
decreased macropore flow, soil water contents, and downward
chemical movement, but increased chemical content of the
macropore flow. Transpiration, on the other hand, decreased
both macropore flow and its chemical content. Thu
23 NAL Call. No.: HC79.E5E5
Classification and spatial mapping of riparian habitat with
applications toward management of streams impacted by nonpoint
source pollution. Delong, M.D.; Brusven, M.A.
New York, N.Y. : Springer-Verlag; 1991 Jul.
Environmental management v. 15 (4): p. 565-571; 1991 Jul.
Includes references.
Language: English
Descriptors: Idaho; Habitats; Riparian vegetation; Erosion;
Pollution; Information systems; Mapping; Watersheds; Farmland
24 NAL Call. No.: 56.8 J822
Classifying remotely sensed data for use in an agricultural
nonpoint-source pollution model.
Jakubauskas, M.E.; Whistler, J.L.; Dillworth, M.E.; Martinko,
E.A. Ankeny, Iowa : Soil and Water Conservation Society of
America; 1992 Mar. Journal of soil and water conservation v.
47 (2): p. 179-183; 1992 Mar. Includes references.
Language: English
Descriptors: Kansas; Water quality; Water pollution; Remote
sensing; Watersheds; Simulation models; Landsat; Thematic
mapper; Data collection
25 NAL Call. No.: SB610.W39
Combining computer simulation with physical simulation: an
attempt to validate turf runoff models.
Lin, J.C.; Graney, R.L.
Champaign, Ill. : The Society; 1992 Jul.
Weed technology : a journal of the Weed Science Society of
America v. 6 (3): p. 688-695; 1992 Jul. Paper presented at a
Symposium on the, "Role of Modeling in Regulatory Affairs," at
the Weed Science Society of America, February 4, 1991,
Louisville, Kentucky. Includes references.
Language: English
Descriptors: Agricultural chemicals; Pesticides; Simulation
models; Runoff; Risk; Aquatic environment; Calibration; Field
tests; Prediction
26 NAL Call. No.: 56.9 SO3
Comparison of models for describing the transport of dissolved
organic carbon in aquifer columns.
Jardine, P.M.; Dunnivant, F.M.; Selim, H.M.; McCarthy, J.F.
Madison, Wis. : The Society; 1992 Mar.
Soil Science Society of America journal v. 56 (2): p. 393-401;
1992 Mar. Includes references.
Language: English
Descriptors: Aquifers; Sediment; Organic matter; Carbon;
Transport processes; Adsorption; Sorption isotherms; Kinetics;
Contaminants; Movement in soil; Mathematical models;
Comparisons
Abstract: Dissolved organic carbon (DOC) is a reactive
constituent in aquifer and soil media and equilibrates between
the mobile aqueous phase and the immobile solid phase. Since
DOC is believed to accelerate the transport of associated
contaminants, yet is known to interact with aquifer and soil
material, our objective was to define and model those
processes governing DOC adsorption to porous media that may
affect the cotransport of contaminants. Column displacement
experiments of DOC through aquifer sediments were modeled with
various formulations of the convective-dispersive equation,
which considered time-dependent adsorption reactions and
linear or nonlinear adsorption processes. Batch equilibrium
adsorption isotherm and kinetic studies for DOC interaction
with the sediments were used to parameterize the transport
models. The equilibrium DOC-adsorption isotherm was nonlinear
and was adequately described by the Langmuir equation. The
adsorption of DOC to the aquifer sediment was also time
dependent and the batch results could be described by two
simultaneous reaction rates for solution concentrations
greater than or equal to 19 mg DOC L-1 and a slow reaction
rate for solution concentrations < 10 mg DOC L-1. Observed DOC
breakthrough curves (BTCs) with influent concentrations
greater than or equal to 10 mg DOC L-1, were adequately
modeled as two-site, non-linear adsorption processes, with DOC
interactions with both types of sites being time dependent.
Batch adsorption and kinetic parameters were generally
successful in describing DOC transport; however, the magnitude
of the initial batch rate coefficient was significantly larger
than that observed for the displacement experiments. The
extended tailing of the observed DOC BTCs was influenced more
by the slow, time-dependent adsorption of DOC during transport
than to the nonlinear features of the adsorption isotherms.
Observed DOC BTCs with influent concentrations < 10 mg DOC L-1
did not exhibit extensive tailing and were
27 NAL Call. No.: QH545.A1E58
Comparison of PRZM and GLEAMS computer model predictions with
field data for alachlor, metribuzin and norflurazon leaching.
Mueller, T.C.; Jones, R.E.; Bush, P.B.; Banks, P.A.
Elmsford, N.Y. : Pergamon Press; 1992.
Environmental toxicology and chemistry v. 11 (3): p. 427-436;
1992. Includes references.
Language: English
Descriptors: Alachlor; Norflurazon; Metribuzin; Herbicide
residues; Leaching; Computer simulation; Simulation models;
Soil depth; Sandy loam soils
28 NAL Call. No.: 292.8 J82 A
comprehensive surface-groundwater flow model.
Arnold, J.G.; Allen, P.M.; Bernhardt, G.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1993 Feb.
Journal of hydrology v. 142 (1/4): p. 47-69; 1993 Feb.
Includes references.
Language: English
Descriptors: Texas; Groundwater; Groundwater flow; Groundwater
level; Surface water; Runoff; Flow; Stream flow; Watersheds;
Catchment hydrology; Land management; Climate; Vegetation;
Water management; Simulation models
Abstract: In this study, a simple groundwater flow and height
model was added to an existing basin-scale surface water
model. The linked model is: (1) watershed scale, allowing the
basin to be subdivided; (2) designed to accept readily
available inputs to allow general use over large regions; (3)
continuous in time to allow simulation of land management,
including such factors as climate and vegetation changes, pond
and reservoir management, groundwater withdrawals, and stream
and reservoir withdrawals. The model is described, and is
validated on a 471 km2 watershed near Waco, Texas. This linked
model should provide a comprehensive tool for water resource
managers in development and planning.
29 NAL Call. No.: 1.98 AG84
Computer model helps ensure clean water.
Cooke, L.
Washington, D.C. : The Service; 1991 Apr.
Agricultural research - U.S. Department of Agriculture,
Agricultural Research Service v. 39 (4): p. 10-12; 1991 Apr.
Language: English
Descriptors: Michigan; Groundwater pollution; Nitrates;
Leaching; Prevention; Computer simulation; Computer techniques
30 NAL Call. No.: SB610.W39
Computer models for fate assessment during the registration
process: data needs.
Behl, E.
Champaign, Ill. : The Society; 1992 Jul.
Weed technology : a journal of the Weed Science Society of
America v. 6 (3): p. 696-700; 1992 Jul. Paper presented at a
Symposium on the, "Role of Modeling in Regulatory Affairs," at
the Weed Science Society of America, February 4, 1991,
Louisville, Kentucky. Includes references.
Language: English
Descriptors: Pesticides; Registration; Simulation models;
Groundwater; Water quality
31 NAL Call. No.: GB701.W375 no.90-4200
Computer software for converting ground-water and water-
quality data from the National Water Information System for
use in a geographic information system.. Software for
converting data from NWIS for use in GIS
Scott, J. C.
Geological Survey (U.S.)
Oklahoma City, Okla. : U.S. Geological Survey ; Denver, Colo.
: Books and Open-File Reports [distributor],; 1991.
iv, 55 p. : ill. ; 28 cm. (Water-resources investigations
report ; 90-4200). Spine title: Software for converting data
from NWIS for use in GIS. Includes bibliographical references
(p. 38-39).
Language: English
Descriptors: Geographic information systems; Water
32 NAL Call. No.: 290.9 AM32T
Computing watershed storage probabilities from rainfall and
runoff data. Mills, W.C.; Thomas, A.W.; Dillard, A.L.; Snyder,
W.M.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 May. Transactions of the ASAE v. 35 (3): p.
891-897; 1992 May. Includes references.
Language: English
Descriptors: Rain; Runoff; Water conservation; Watersheds;
Mathematical models; Probability
Abstract: This article describes the development and
application of a computational procedure for obtaining
watershed storage probabilities that are corrected for bias
toward lower storage, which is inherent in storage values
computed directly from rainfall and runoff data. The developed
procedure makes use of rainfall and runoff data from
watersheds, and also incorporates probabilities for rainfall
needed to produce runoff for various storages. The procedure
is derived mathematically using basic probability concepts and
employs numerical integration and nonlinear least squares
optimization in the solution. The procedure is applied to
rainfall and runoff data collected from a Southern Piedmont
field watershed over a 10-year period during which a
conventional tillage system for crops was followed by two
successive conservation tillage systems. Results of the
application show that the developed computational procedure
performs adequately in providing bias-corrected watershed
storage probabilities that reflect effects of the three
cropping/tillage systems on watershed storage.
33 NAL Call. No.: TD426.J68
Conditional simulation of flow and transport.
Rogowski, A.S.; Wolf, J.K.; Simmons, D.E.
Amsterdam : Elsevier; 1991 Jan.
Journal of contaminant hydrology v. 7 (1/2): p. 95-121; 1991
Jan. Includes references.
Language: English
Descriptors: Groundwater pollution; Leachates; Movement in
soil; Groundwater recharge; Clay; Subsoil; Infiltration;
Spatial distribution; Simulation models; Spatial variation
34 NAL Call. No.: aSD11.A42
The conservation reserve program: effects on soil, water and
environmental quality.
Blackburn, W.H.; Newman, J.B.; Wood, J.C.
Fort Collins, Colo. : The Station; 1991 May.
General technical report RM - Rocky Mountain Forest and Range
Experiment Station, U.S. Department of Agriculture, Forest
Service (203): p. 27-36; 1991 May. Includes references.
Language: English
Descriptors: U.S.A.; Soil conservation; Erosion control;
Federal programs; Reserved areas; Simulation models;
Percolation; Evapotranspiration; Water erosion; Runoff
35 NAL Call. No.: TD420.A1E5
Convective transport of gases in moist porous media: effect of
absorption, adsorption, and diffusion in soil aggregates.
McCoy, B.J.; Rolston, D.E.
Washington, D.C. : American Chemical Society; 1992 Dec.
Environmental science & technology v. 26 (12): p. 2468-2476;
1992 Dec. Includes references.
Language: English
Descriptors: Soil pollution; Groundwater pollution; Volatile
compounds; Mathematical models
36 NAL Call. No.: TC401.W27 A
coupled rainfall-runoff and runoff-routing model for adaptive
real-time flood forecasting.
Habaieb, H.; Troch, P.A.; Troch, F.P. de
Hingham, Mass. : Kluwer Academic Publishers; 1991.
Water resources management v. 5 (1): p. 47-61; 1991. Includes
references.
Language: English
Descriptors: Belgium; Floods; Forecasting; Rain; Runoff;
Models; On line; Identification; Case studies
37 NAL Call. No.: 292.8 J82
Coupled simulations of water flow from a field-investigated
glacial till slope using a quasi-two-dimensional water and
heat model with bypass flow. Espeby, B.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Feb.
Journal of hydrology v. 131 (1/4): p. 105-132; 1992 Feb.
Includes references.
Language: English
Descriptors: Sweden; Glacial till soils; Forest soils;
Coniferous forests; Picea abies; Pinus sylvestris; Slopes;
Water flow; Macropore flow; Meltwater; Precipitation; Runoff;
Soil water retention; Saturated hydraulic conductivity;
Macropores; Soil temperature; Soil depth; Physical models;
Simulation models
Abstract: Substantial field investigations of soil physical
properties and stratification in a forested slope (10 degrees
slope) covered with glacial till revealed that macropores in
the form of old root channels as well as coarse structures in
the form of well-sorted layers dominate a very permeable upper
solid horizon. Rapid response and quick recessions during
snowmelt and heavy rains in 1986 were observed in the runoff
from the slope. Based on field tracer experiments it was found
that such macropores and macrostructures played an important
role on these occasions. In order to verify these findings
one-dimensional water and heat models were coupled in a serial
manner to simulate the formation of runoff from the slope,
using a quasi-two-dimensional approach. Both a strict Darcian
concept and a Darcian concept with a simple bypass flow
concept introduced were tested. The drainage gradient in the
model was made equal with the angle of the slope. Coupled
slope simulations, with water retention properties and
hydraulic conductivities taken from three different levels on
the slope, indicated that the conditions in the lower region
of the slope were most important in explaining the discharge
rate. With a shallow groundwater table in the lower region of
the slope and low hydraulic conductivity of the deeper layers,
rapid water flows are routed to the uppermost layers where the
conductivity is higher. Most of the flow is well described by
Richards' equation, although smaller peaks cannot be
represented for small rain events, when the measured runoff
and recession showed a more rapid response than that
simulated, however, the introduction of a simple bypass flow
improved the ability of the model to simulate the
observations. Much of the simulated surface runoff generated
in the Darcian simulation during the winter of 1986, could be
diverted through a frost layer in the humus horizon and in the
humus-impregnated mineral horizon with a silty-sand character,
down to a more conductiv
38 NAL Call. No.: QH540.J6
Coupling groundwater contamination with economic returns when
applying farm pesticides.
Hoag, D.L.; Hornsby, A.G.
Madison, Wis. : American Society of Agronomy; 1992 Oct.
Journal of environmental quality v. 21 (4): p. 579-586; 1992
Oct. Includes references.
Language: English
Descriptors: North Carolina; Groundwater pollution;
Methodology; Pesticides; Usage; Economic impact; Returns;
Profitability; Environmental impact; Glycine max; Weed
control; Costs; Crop yield; Weed competition; Leaching;
Simulation models
Abstract: A methodology is presented that permits
simultaneous consideration of the economics of production and
groundwater contamination hazard of pesticide use. An example
is constructed for weed control in soybean (Glycine max L.)
production at Clayton, NC. A cost/groundwater hazard frontier
is developed that can be used to identify and illustrate the
cost tradeoffs of selecting alternative weed control
strategies that reduce the risk of adverse health effects from
drinking contaminated groundwater. The methodology relies on
models to estimate costs, crop yields, pest competition, and
leaching of pesticides; thus, its applicability depends on
availability of local data and appropriately validated models
for the site considered. The cost/groundwater hazard frontier
provides a useful decision aid to assist pesticide users in
making cost-effective and environmentally favorable production
decisions. It is also useful in evaluating policy or the value
of new pest control technologies, as it indicates a farmer's
ability to substitute alternatives for currently used
practices.
39 NAL Call. No.: 381 J8224
Criteria to assess when biodegradation is kinetically limited
by intraparticle diffusion and sorption.
Chung, G.Y.; McCoy, B.J.; Scow, K.M.
New York, N.Y. : John Wiley & Sons; 1993 Mar15.
Biotechnology and bioengineering v. 41 (6): p. 625-632; 1993
Mar15. Includes references.
Language: English
Descriptors: Soil flora; Microbial degradation; Pollutants;
Transport processes; Diffusion; Sorption; Desorption; Polluted
soils; Soil pollution; Mathematical models; Bioremediation
Abstract: To determine when intraparticle diffusion and
sorption can influence the rate of biodegradation, we consider
the biodegradation of a pollutant diffusing into or out of
porous aggregates suspended in a liquid medium, where the
reactant is metabolized by bacteria. The pollutant that
diffuses into the aggregates obeys a sorption-desorption
equilibrium isotherm at sites on inner pore surfaces. The
governing partial differential equations for the transient
process describe (a) the local equilibrium sorption-desorption
and the diffusion of the pollutant in the porous aggregate,
(b) the mass transfer of the pollutant from the external
surface of the spherical aggregates to the reaction medium,
and (c) the biodegradation of the pollutant in the external
medium. Illustrative calculations are presented for a linear
sorption isotherm and first-order biodegradation kinetics. A
dimensionless group, comprised of the diffusion coefficient,
biodegradation rate coefficient, aggregate characteristic
length (radius), and adsorption capacity, serves as a
criterion for determining when intraparticle diffusion
resistance can be ignored. The model provides a realistic
description of experimental data for biodegradation of a
pollutant subject to intraparticle diffusion and sorption.
40 NAL Call. No.: TD420.A1P7
DBAPE--a database and model parameter analysis system for
agricultural soils to support water quality management.
Imhoff, J.C.; Carsel, R.F.; Kittle, J.L. Jr; Hummel, P.R.
Oxford : Pergamon Press; 1991.
Water science and technology : a journal of the International
Association on Water Pollution Research and Control v. 24 (6):
p. 331-337; 1991. In the series analytic: Watermatex '91 /
edited by T.O. Barnwell, P.J. Ossenbruggen and M.B. Beck.
Proceedings of the "Second International Conference on Systems
Analysis in Water Quality Management," June 3-6, 1991, Durham,
New Hampshire. Includes references.
Language: English
Descriptors: Soil properties; Water quality; Management;
Agricultural soils; Computer software; Subsurface runoff;
Models; Databases
41 NAL Call. No.: QH540.J6
Degradation and transport of dicamba in a clay soil.
Comfort, S.D.; Inskeep, W.P.; Macur, R.E.
Madison, Wis. : American Society of Agronomy; 1992 Oct.
Journal of environmental quality v. 21 (4): p. 653-658; 1992
Oct. Includes references.
Language: English
Descriptors: Dicamba; Clay soils; Degradation; Leaching; Soil
water movement; Soil temperature; Persistence; Half life;
Precipitation; Irrigation scheduling; Simulation models
Abstract: Dicamba (3,6-dichloro-2-methoxybenzoic acid) has
been identified as one of five pesticides present in Montana
groundwaters. We determined the effects of degradation and
time of water application on the transport of dicamba in a
Lohmiller clay soil (fine, montmorillonitic, mesic Ustic
Torrifluvent). Carbon 14-labeled dicamba was surface applied
(0.35 kg ha-1) to disturbed soil columns (5.0 cm diam; 29 cm
length) previously conditioned with 3 mM CaCl2. The columns
were allowed to incubate (23.5 degrees C) in triplicate for 0,
14, 21, 28, and 42 d. Following incubation, the columns were
attached to a vacuum chamber containing a fraction collector
and leached with 3 mM CaCl2 under unsaturated conditions.
Dicamba breakthrough curves were determined for each
incubation period. The percentage of dicamba recovered in the
column effluent decreased from 85% (of total applied) after no
incubation to 9.5% after 42 d of incubation. The decline of
dicamba in the effluent coincided with an accumulation of
dichlorosalicyclic acid at the soil surface. Dicamba half-
lives determined under batch conditions were 23.5 d at 28
degrees C, 38 d at 20 degrees C, and 151 d at 12 degrees C,
and were all higher than the half-life estimated from the
decrease in column effluent concentrations over time (13.5 d).
The simulation model, LEACHM, was used to predict transport of
dicamba after the different incubation periods. LEACHM
adequately estimated the mass of dicamba leached, but
underestimated the maximum dicamba concentrations observed in
the effluent. Both simulated and observed results indicated
that the transport of dicamba can be greatly reduced if
sufficient degradation of dicamba is allowed to occur before
irrigation or precipitation.
42 NAL Call. No.: QC851.J62 A
description of rainfall interception over large areas.
Eltahir, E.A.B.; Bras, R.L.
Boston, MA : American Meteorological Society, c1988-; 1993
Jun. Journal of climate v. 6. (6): p. 1002-1008; 1993 Jun.
Includes references.
Language: English
Descriptors: Rain; Ground vegetation; Canopy; Drainage; Runoff
water; Interception; Evaporation; Models; Climatic factors
Abstract: A new scheme is developed for describing
interception at spatial scales comparable to the typical
resolution of climate models. The scheme is based on the
Rutter model of interception and statistical description of
the subgrid-scale spatial variability of canopy storage and
rainfall. The interception loss simulated by the new scheme is
significantly smaller than those simulated by other schemes
that do not include considerations for spatial variability.
The explanation of this result is partly in the enhancement of
spatially averaged canopy drainage due to the large local
drainage from the few buckets of large canopy storage. The
relative reduction in interception loss simulated by the new
scheme may explain the overestimation of interception loss by
climate models that do not include the effects of spatial
variability on interception processes.
43 NAL Call. No.: TD403.G7
Design and evaluation of a mesoscale model vadose zone and
ground-water system.
Lawrence, J.R.; Zanyk, B.N.; Hendry, M.J.; Wolfaardt, G.M.;
Robarts, R.D.; Caldwell, D.E.
Dublin, Ohio : Ground Water Pub. Co; 1993 May.
Ground water v. 31 (3): p. 446-455; 1993 May. Includes
references.
Language: English
Descriptors: Groundwater pollution; Soil pollution;
Contaminants; Movement in soil; Chemical degradation;
Microbial degradation; Models; Agricultural chemicals
Abstract: A mesoscale model soil and ground-water system was
constructed and instrumented to study physical, chemical, and
microbial processes, including transport and degradation of
contaminants. The model system was 4.6 m in height by 2.4 m in
diameter and contained up to 65 tonnes of soil and geologic
materials. The model was filled with Ap (11 cm), B (20 cm), Cl
and C2 (369 cm) horizons; the water table was 3.3 m from the
soil surface. A rain simulation system applied uniform
coverage of rain and/or chloride tracer to the model. Sampling
of soil, sediment, pore waters, and gas phase was carried out
using a series of in situ collectors and sampling ports. Major
anions, metals, pH, alkalinity, CO2, N2, O2, CH4, microbial
numbers, microbial biomass and heterotrophic potential (14 C-
amino-acid uptake) were monitored over time (120 days) and
depth. The system approached steady state with respect to
solution chemistry and gases after approximately 60-70 days.
During this interval, carbon dioxide rose from atmospheric to
3-5% of total gas volume measured at each sampling depth above
the water table. Physical, chemical, and biological conditions
in the model system after the initial 120 days were comparable
to those reported for vadose and saturated zones during field
studies on shallow phreatic aquifers. These results indicated
that the mesoscale model preserved many of the features of
natural systems while providing controlled conditions for
studies such as evaluating the fate, and ground-water
contamination potential, of agricultural and industrial
chemicals.
44 NAL Call. No.: TD201.A4
Design of optimal pump-and-treat strategies of contaminated
groundwater remediation using the simulated annealing
algorithm.
Kuo, C.H.; Michel, A.N.; Gray, W.G.
Essex : Elsevier Science Publishers Ltd; 1992.
Advances in water resources v. 15 (2): p. 95-105; 1992.
Includes references.
Language: English
Descriptors: Groundwater pollution; Problem solving; Pumps;
Placement; Optimization methods; Hydraulics; Constraints;
Simulation models; Algorithms
45 NAL Call. No.: TD403.G7
Designing a nitrate monitoring program in a heterogeneous,
carbonate aquifer. Smith, R.T.; Ritzi, R.W. Jr
Dublin, Ohio : Ground Water Pub. Co; 1993 Jul.
Ground water v. 31 (4): p. 576-584; 1993 Jul. Includes
references.
Language: English
Descriptors: Ohio; Aquifers; Carbonates; Hydraulic
conductivity; Finite element analysis; Simulation models;
Nitrates; Movement in soil; Zea mays; Glycine max; Rotations;
Groundwater pollution
46 NAL Call. No.: 292.9 AM34
Determination of best timing for poultry waste disposal: a
modeling approach. Edwards, D.R.; Daniel, T.C.; Marbun, O.
Bethesda, Md. : American Water Resources Association; 1992
May. Water resources bulletin v. 28 (3): p. 487-494; 1992 May.
Includes references.
Language: English
Descriptors: Arkansas; Poultry manure; Waste disposal;
Application to land; Application date; Timing; Surface water;
Runoff water; Water quality; Nitrogen; Phosphorus; Losses from
soil systems; Grasses; Crop production; Crop yield
Abstract: Confined production of poultry results in
significant volumes of waste material which are typically
disposed of by land application. Concerns over the potential
environmental impacts of poultry waste disposal have resulted
in ongoing efforts to develop management practices which
maintain high quality of water downstream of disposal areas.
The timing of application to minimize waste constituent losses
is a management practice with the potential to ensure high
quality of streams, rivers, and lakes downstream of receiving
areas. This paper describes the development and application of
a method to identify which time of year is best, from the
standpoint of surface water quality, for land application of
poultry waste. The procedure consists of using a mathematical
simulation model to estimate average nitrogen and phosphorus
losses resulting from different application timings, and then
identifying the timings which minimize losses of these
nutrients. The procedure was applied to three locations in
Arkansas, and three different criteria for optimality of
application timing were investigated. One criterion was
oriented strictly to water quality, one was oriented only to
crop production, and the last was a combination. The criteria
resulted in different windows of time being identified as
optimal. Optimal windows also varied with location of the
receiving area. The results indicate that it is possible to
land-apply poultry waste at times which both minimize nutrient
losses and maximize crop yield.
47 NAL Call. No.: SB951.P47
Development and validation of a modified fugacity model of
pesticide leaching from farmland.
Brooke, D.; Matthiessen, P.
Essex : Elsevier Applied Science Publishers; 1991.
Pesticide science v. 31 (3): p. 349-361; 1991. Includes
references.
Language: English
Descriptors: England; Mecoprop; Simazine; Concentration;
Leaching; Measurement; Models; Monitoring; Soil properties;
Water pollution; Agricultural soils
Abstract: To test whether a simple model could provide
reasonable quantitative estimates of chemical concentrations
in a dynamic situation, Mackay's fugacity model was adapted to
represent an agricultural field. The intention was to
determine the extent of modification required to obtain
reasonable agreement with experimental results, or indeed if
such agreement could be achieved. The validity of the model
was tested at Rosemaund Experimental Husbandry Farm in
Herefordshire, where the chemical input and output could be
monitored and meteorological and other parameters measured
regularly. Results from monitoring concentrations of two
pesticides at this site in recent years. and changes that have
been made to the model in attempting to fit the observed
behaviour are described.
48 NAL Call. No.: QH540.J6
Development of a database and model parameter analysis system
for agricultural soils.
Carsel, R.F.; Imhoff, J.C.; Kittle, J.L. Jr; Hummel, P.R.
Madison, Wis. : American Society of Agronomy; 1991 Jul.
Journal of environmental quality v. 20 (3): p. 642-647; 1991
Jul. Includes references.
Language: English
Descriptors: Water quality; Water management; Databases;
Computer software; Water flow
Abstract: An interactive computer program was developed for
obtaining soils data for geographic analyses and estimation of
soil water retention data for simplistic and classical water
flow models. The soils data base contains 8080 soil series
identified from the USDA-SCS. The data are organized in
sequential files that contain textural, morphological crop
support, and geographical location (at a county level) and
density (ha/county). The computer program allows the
exploration of the database, clarifying the impact of data on
modeled processes, screening geographically based data to
identify potential sites for model application or testing, and
developing initial guidance on alternative water quality
management strategies. The program allows the display of data
in the form of generated reports and production of geographic
maps and plots of soil water functional relationships.
Indirect methods are used in the program for estimating soil
water retention characteristics using textural information
from the soil data base. Estimates of variability can be
developed within a soil series or among series by using
reported ranges for textural information on each series
contained in the soil database.
49 NAL Call. No.: S592.7.A1S6
Dispersion effect on the apparent nitrogen isotope
fractionation factor associated with denitrification in soil;
evaluation by a mathematical model. Kawanishi, T.; Hayashi,
Y.; Kihou, N.; Yoneyama, T.; Ozaki, Y. Exeter : Pergamon
Press; 1993 Mar.
Soil biology and biochemistry v. 25 (3): p. 349-354; 1993 Mar.
Includes references.
Language: English
Descriptors: Denitrification; Quantitative analysis;
Agricultural soils; Solutes; Dispersion; Transport processes;
Soil water; Water flow; Mathematical models; Nitrate;
Groundwater pollution
Abstract: An analytical model is constructed to investigate
the effect of dispersion on the apparent 15N/14N fractionation
factor associated with denitrification in soil. The steady
input of solute with a fixed isotope ratio, uniform flow of
the solute, and the first-order reaction for each isotope are
assumed, and the relationship between the concentration
distribution and the change of isotope ratio in the steady
state is examined. The only dimensionless parameter, kl4ND/v2,
the product of the first-order reaction rate constant and the
dispersion coefficient divided by the square of the
superficial velocity, determines the effect of dispersion, and
if its value is larger than 0.01, the dispersion will affect
the apparent isotope fractionation factor. As kl4ND/v2
increases, the effect becomes more prominent, and when it
approaches infinity, the ratio of the apparent per mille
enrichment factor to the true one, (alpha ap-1)/(alpha tr-1),
reaches 0.5.
50 NAL Call. No.: GB701.W375 no.93-4015
Documentation of geographic-information-system coverages and
data-input files used for analysis of the geohydrology of the
Virginia Coastal Plain.. Documentation of geographic
information system coverages and data input files used for
analysis of the geohydrology of the Virginia Coastal Plain
Focazio, Michael J.; Samsel, Theodore B.
Geological Survey (U.S.),Hampton Roads Planning District
Commission (Va.),Virginia Water Control Board
Richmond, Va. : U.S. Geological Survey ; Denver, CO : Books
and Open-File Reports Section [distributor],; 1993; I
19.42/4:93-4015.
vi, 53 p. : maps ; 28 cm. (Water-resources investigations
report ; 93-4015). Shipping list no.: 93-0451-P. Includes
bibliographical references (p. 11).
Language: English; English
Descriptors: Hydrogeology; Geographic information systems
51 NAL Call. No.: 292.8 W295 A
dual-porosity model for simulating the preferential movement
of water and solutes in structured porous media.
Gerke, H.H.; Van Genuchten, M.T.
Washington, D.C. : American Geophysical Union; 1993 Feb.
Water resources research v. 29 (2): p. 305-319; 1993 Feb.
Includes references.
Language: English
Descriptors: Transport processes; Solutes; Water flow;
Saturated flow; Transient flow; Leaching; Porous media;
Physicochemical properties; Deterministic models; Mathematical
models; Equations
Abstract: A one-dimensional dual-porosity model has been
developed for the purpose of studying variably saturated water
flow and solute transport in structured soils or fractured
rocks. The model involves two overlaying continua at the
macroscopic level: a macropore or fracture pore system and a
less permeable matrix pore system. Water in both pore systems
is assumed to be mobile. Variably saturated water flow in the
matrix as well as in the fracture pore system is described
with the Richards' equation, and solute transport is described
with the convection-dispersion equation. Transfer of water and
solutes between the two pore regions is simulated by means of
first-order rate equations. The mass transfer term for solute
transport includes both convective and diffusive components.
The formulation leads to two coupled systems of nonlinear
partial differential equations which were solved numerically
using the Galerkin finite element method. Simulation results
demonstrate the complicated nature of solute leaching in
structured, unsaturated porous media during transient water
flow. Sensitivity studies show the importance of having
accurate estimates of the hydraulic conductivity near the
surface of soil aggregates or rock matrix blocks. The proposed
model is capable of simulating preferential flow situations
using parameters which can be related to physical and chemical
properties of the medium.
52 NAL Call. No.: 100 C12CAG
Dupuit-Forchheimer approximation may underestimate groundwater
flow to San Joaquin River.
Grismer, M.E.; Rashmawi, E.A.
Oakland, Calif. : Division of Agriculture and Natural
Resources, University of California; 1993 Jan.
California agriculture v. 47 (1): p. 12, 13-15; 1993 Jan.
Language: English
Descriptors: California; Groundwater flow; River water; Water
quality; Water management; Salinity; Estimation; Water table;
Errors; Mathematical models
53 NAL Call. No.: GB746.W33
Dynamic-probabilistic models for the formation of rainfall and
snowmelt runoff.
Kuchment, L.S.; Gel'fan, A.N.
New York, N.Y. : Consultants Bureau; 1992 May.
Water resources v. 18 (4): p. 335-343; 1992 May. Translated
from: Vodnye Resursy, v. 18 (4), 1991, p. 5-14, (GB746.V55).
Includes references.
Language: English; Russian
Descriptors: U.S.S.R.in europe; Rain; Meltwater; Floods;
Runoff water; Watersheds; Forest steppe; Zoning; Probabilistic
models; Dynamic models; Physical models; Mathematical models;
Weather data
54 NAL Call. No.: HD101.S6
Economic impacts of chemical use reduction on the South.
Taylor, C.R.; Penson, J.B. Jr; Smith, E.G.; Knutson, R.D.
Experiment, Ga. : The Association; 1991 Jul.
Southern journal of agricultural economics - Southern
Agricultural Economics Association v. 23 (1): p. 15-23; 1991
Jul. Discussion by J.R. Schaub, p. 25-26. Includes
references.
Language: English
Descriptors: Southern states of U.S.A.; Agricultural
chemicals; Pesticide residues; Water quality; Groundwater;
Contamination; Food safety; Agricultural policy; Models;
Economic impact; Income
55 NAL Call. No.: HD1.A3
The economics of water harvesting and supplementary irrigation
in the semi-arid tropics of India.
Pandey, S.
Essex : Elsevier Applied Science Publishers; 1991.
Agricultural systems v. 36 (2): p. 207-220; 1991. Includes
references.
Language: English
Descriptors: Madhya pradesh; Soybeans; Wheat; Water
harvesting; Irrigation; Cropping systems; Semiarid zones;
Agricultural regions; Economic evaluation; Feasibility; Risk;
Simulation models; Soil water balance; Yield response
functions; Water relations; Decision making; Rain; Runoff
water
56 NAL Call. No.: 56.8 SO3
The effect of soil P sorption kinetics on parameters used for
modeling P uptake.
Shnek, M.; Shaviv, A.; Ravina, I.
Baltimore, Md. : Williams & Wilkins; 1991 May.
Soil science v. 151 (5): p. 333-342; 1991 May. Includes
references.
Language: English
Descriptors: Calcareous soils; Soil physics; Phosphorus;
Sorption; Kinetics; Diffusion models; Desorption; Mathematical
models; Soil solution; Equilibrium; Buffering capacity;
Nutrient uptake; Prediction; Equations; Solubility; Nutrient
availability; Transport processes
57 NAL Call. No.: 56.8 SO3
The effect of soil properties on phosphorus sorption by
everglades histosols. Porter, P.S.; Sanchez, C.A.
Baltimore, Md. : Williams & Wilkins; 1992 Nov.
Soil science v. 154 (5): p. 387-398; 1992 Nov. Includes
references.
Language: English
Descriptors: Florida; Histosols; Agricultural soils;
Phosphorus; Sorption; Movement in soil; Leaching; Losses from
soil systems; Soil chemistry; Soil properties; Water
pollution; Indexes; Models
58 NAL Call. No.: 292.8 J82
The effect of transverse dispersion on solute transport in
soils. Leij, F.J.; Dane, J.H.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1991 Jan.
Journal of hydrology v. 122 (1/4): p. 407-422; 1991 Jan.
Includes references.
Language: English
Descriptors: Solutes; Transport processes; Horizontal flow;
Two dimensional flow; Transverse distribution; Permeability;
Simulation; Mathematical models
Abstract: Most theoretical and experimental investigations of
solute transport involve one-dimensional problems (i.e. soil
column studies), whereas in reality many soil pollution
problems concern transport and flow in more than one
dimension. This study investigates two-dimensional transport,
with emphasis on the contribution of transverse dispersion to
solute transport. Three problems were studied with a finite
element code. The first problem involved one-dimensional flow
parallel to the interface of two layers with differing pore-
water velocity. The early arrival of the solute at the end of
the low-permeability layer and the increase-in solute
spreading for both layers, as a result of transverse
dispersion, were demonstrated. The two other problems
concerned transport of a pollutant from a point source and a
diffuse source, respectively, located at the soil surface. The
magnitude of the transverse dispersion coefficient influenced
the region to which the pollution extended as well as the
intensity of the pollution.
59 NAL Call. No.: 292.8 W295
The effect of vertical soil heterogeneity on field scale
solute flux. Destouni, G.
Washington, D.C. : American Geophysical Union; 1992 May.
Water resources research v. 28 (5): p. 1303-1309; 1992 May.
Includes references.
Language: English
Descriptors: Solutes; Transport processes; Flow; Saturated
hydraulic conductivity; Soil depth; Stochastic models
Abstract: Vertical heterogeneity is incorporated in a
stochastic transport model, in which the soil is viewed as
consisting of an ensemble of essentially vertical, independent
stream tubes. The saturated hydraulic conductivity in each
stream tube is defined as the vertical average of the
corresponding point random process. The statistics of the
vertically averaged hydraulic conductivity and the resulting
statistics of solute travel time are depth dependent. The
evolution of the field scale breakthrough curve with depth is
analyzed in terms of the first two moments of solute travel
time to an arbitrary depth below the soil surface. The arrival
time of the solute center of mass, quantified by the expected
travel time, grows linearly with depth also for vertically
heterogeneous soil. The temporal solute spreading around its
center, quantified by the travel time variance, may exhibit a
compression-expansion that is qualitatively analogous to the
solute plume behavior in the studies of Butters and Jury
(1989), Russo (1991), and Ellsworth and Jury (1991). The
relative solute spreading, quantified by the travel time
coefficient of variation, decreases with increasing depth.
60 NAL Call. No.: QH540.J6
Effects of climatic variations over 11 years on nitrate-
nitrogen concentrations in the Raccoon River, Iowa.
Lucey, K.J.; Goolsby, D.A.
Madison, Wis. : American Society of Agronomy; 1992 Jan.
Journal of environmental quality v. 22 (1): p. 38-46; 1992
Jan. Includes references.
Language: English
Descriptors: Iowa; Nitrate nitrogen; Drinking water; Seasonal
variation; Precipitation; Stream flow; Water quality; Water
pollution; Nitrogen fertilizers; Mathematical models
Abstract: Nitrate-nitrogen (NO3-N) concentrations at public
water-supply intakes on the Des Moines and Raccoon Rivers in
Iowa exceeded the maximum contaminant level (MCL) of 10 mg L-1
for public water supplies established by the USEPA for
extended periods of time from March through early August 1990.
The excessive NO3-N levels followed 2 yr of less than normal
precipitation in 1988 and 1989. The largest daily NO3-N load
(771 t) transported during the last 17 yr in the Raccoon River
occurred in June 1990. The streamflow hydrograph for the
Raccoon River for March 1990 prior to seasonal fertilizer
application indicates that high NO3-N concentrations
characterize the recession side of the hydrograph. High NO3-N
concentrations in streamflow persisted as streamflow decreased
to baseflow conditions. This implies that substantial
quantities of NO3-N were being leached from the soil and
transported by subsurface flow during early 1990. A multiple
linear-regression model was developed to predict NO3-N
concentrations in the Raccoon River from readily-obtainable
streamflow and climatic data. The four-variable model
explained about 70% of the variability in the concentration of
NO3-N. The mean streamflow for the previous 7-d period
accounted for about 50% of the total variability.
61 NAL Call. No.: 290.9 AM32T
Effects of pesticide, soil, and rainfall characteristics on
potential pesticide loss by percolation--a GLEAMS simulation.
Truman, C.C.; Leonard, R.A.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 Nov. Transactions of the ASAE v. 34 (6): p.
2461-2468; 1991 Nov. Includes references.
Language: English
Descriptors: Georgia; Pesticides; Percolation; Leaching;
Losses from soil systems; Water pollution; Groundwater;
Computer simulation; Zea mays
Abstract: Potential pesticide loss in soil percolate is
influenced by pesticide persistence and sorption by soil
constituents (organic matter). Pesticide persistence,
expressed as half-life (t1/2), changes with soil depth as
microbial activity and soil properties change. Little is
known, however, how these changes influence potential
pesticide transport out of the root zone. Objectives of this
study were to investigate relative differences in potential
pesticide losses from the root zone by percolation due to 1)
different soil surface and subsurface textures and pesticide
t1/2, and 2) interactions between pesticide t1/2 arid timing
of rainfall after pesticide application. The GLEAMS
(Groundwater Loading Effects of Agricultural Management
Systems) model and a 50-year historical rainfall record at
Tifton, Georgia, were used to simulate pesticide losses by
percolation from three soils ranging in surface texture from
sand to sandy clay loam. Hypothetical pesticides had surface
t1/2 of 5, 15, 30, and 60 d and a range of subsurface t1/2
(2.5-360 d), and were applied to continuous corn (Zea maize,
L.) at 2 kg ha-1 as surface spray at planting each year on 1
April. Simulated pesticide losses by percolation increased
with increased surface and subsurface t1/2, and decreased with
increased KOC (adsorption constant based on soil organic
matter) values. Potential pesticide leaching was greatest for
Lakeland sand and least for Greenville sandy clay loam.
Rainfall timing affected simulated pesticide loss by
percolation, especially for nonpersistent pesticides. For
short pesticide t1/2 (0-5 d), excessive rainfall events within
1 t1/2 were largely responsible for simulated pesticide loss
by percolation. Results indicate that changes in pesticide
t1/2 in surface and subsurface horizons of different soils
influence potential pesticide leaching from the root zone, and
models (i.e., GLEAMS) can be used to provide comparative
analysis of soil-pesticide-climate interactions. For example,
dependi
62 NAL Call. No.: 292.8 W295
Effects of rainfall, vegetation, and microtopography on
infiltration and runoff.
Dunne, T.; Zhang, W.; Aubry, B.F.
Washington, D.C. : American Geophysical Union; 1991 Sep.
Water resources research v. 27 (9): p. 2271-2285; 1991 Sep.
Includes references.
Language: English
Descriptors: Soil water; Infiltration; Runoff; Rain; Hill
grasslands; Slope; Plant density; Hydraulic conductivity;
Mathematical models
Abstract: Apparent, or effective, infiltration rates on
grassland hillslopes vary with rainfall intensity and flow
depth because of the interaction between rainfall, runoff, and
vegetated microtopography. The higher parts of the
microtopography are occupied by greater densities of
macropores and therefore have much greater hydraulic
conductivities than the intervening microdepressions. On short
hillslopes and plots the apparent infiltration rate is simply
the spatial average of the saturated and unsaturated
conductivities of this surface. The proportion of the surface
which is saturated and the value to which the unsaturated
conductivity is raised depends on the rainfall intensity. On
longer hillslopes the downslope increase in flow depth in
microtopographic depressions progressively inundates more
permeable, vegetated mounds so that the hydraulic conductivity
of a greater proportion of the surface is raised to its
saturated value. For this reason the apparent infiltration
rate increases downslope, even in the absence of spatial
trends in any of the surface characteristics that affect
infiltration. Apparent, or effective, infiltration rate
depends on hillslope length. Consequently, steady state
discharge does not increase linearly with distance downslope.
These two fundamental relationships between infiltration,
rainfall intensity, and runoff are analyzed on the basis of
sprinkling-infiltrometer measurements and a mathematical
model.
63 NAL Call. No.: 292.8 W295
Effects of soil heterogeneity on pesticide leaching to
groundwater. Zee, S.E.A.T.M. van der; Boesten, J.J.T.I.
Washington, D.C. : American Geophysical Union; 1991 Dec.
Water resources research v. 27 (12): p. 3051-3063; 1991 Dec.
Includes references.
Language: English
Descriptors: Pesticides; Groundwater; Leaching; Hydrodynamic
dispersion; Sorption; Transformation; Uptake; Physicochemical
properties; Spatial variation; Stochastic models; Monte carlo
method
Abstract: Pesticide leaching was simulated numerically
assuming Freundlich adsorption, first-order transformation and
passive plant uptake, taking transient flow, hydrodynamic
dispersion, and depth as well as temperature dependence of
(bio)chemical parameters into account. The dependency of the
leached fraction on sorption and transformation parameters
appeared to be in good general agreement with the model
developed by Jury et al. (1987). We incorporated spatial
variability of (bio)chemical parameters into the piston flow
model and showed how spatial variability may be accounted for
without having to resort to demanding Monte Carlo techniques.
Such spatial variability affects the leached fraction
significantly. The data requirement of the simple stochastic
model is small and the versatility relatively high. For
parameter values often not of prime practical interest for
pesticide screening this model fails. Considering transport by
convection and dispersion in the semi-infinite domain, this
spatial variability can be easily accounted for using
parameter ranges for which our original analytical model for
spatially variable piston transport failed. In this revised
model, hydrodynamic dispersion, preferential flow, and spatial
variability of transformation, sorption and soil thickness are
dealt with in a similar fashion, while both correlation or the
absence of correlation of parameters can be incorporated
through an approximation of apparent residence time variance.
64 NAL Call. No.: QH540.J6
Effects of spatial accumulation of runoff on watershed
response. Garbrecht, J.
Madison, Wis. : American Society of Agronomy; 1991 Jan.
Journal of environmental quality v. 20 (1): p. 31-35; 1991
Jan. Literature review. Includes references.
Language: English
Descriptors: Watersheds; Drainage; Hydrology; Rain; Runoff;
Simulation models
Abstract: The drainage network accumulates upstream
subwatershed runoff into a single downstream response, with
runoff accumulating at network junctions. The effects of this
accumulation on the magnitude and spatial variability of the
downstream response are reviewed for simplified boundary
conditions. Runoff parameters are runoff depth and
corresponding unit area peak runoff rate. At the subwatershed
level these parameters are referred to as d and q,
respectively, and they vary from one subwatershed to another.
At a downstream location, after accumulation by the drainage
network, corresponding parameters are referred to as D and Q.
Equations expressing the effects of runoff accumulation are
formulated and discussed for uniform rainfall conditions. The
review shows that the effects of runoff accumulation gain in
importance as the number of upstream subwatersheds and the
size of the watershed increase in the downstream direction.
The accumulation process cancels extreme values of d and q to
yield a representative D and Q value for the entire upstream
drainage area. The impact of individual d and q values on the
downstream D and Q values in the channel diminishes as the
number of upstream subwatersheds increases. This results in a
decrease in the spatial variability of D and Q in the
downstream direction. The review suggests that the role of
spatial variability of upstream d and q in the determination
of downstream D and Q diminishes as watershed size increases.
However, nonuniform rainfall distributions and storm movement
may overshadow the effects of runoff accumulation when
watershed size increases beyond the size of the storm.
65 NAL Call. No.: 325.28 P56
Effects of suspended particle size and concentration on
reflectance measurements.
Bhargava, D.S.; Mariam, D.W.
Bethesda, Md. : American Society of Photogrammetry and Remote
Sensing; 1991 May.
Photogrammetric engineering and remote sensing v. 57 (5): p.
519-529; 1991 May. Includes references.
Language: English
Descriptors: Soil types; Suspensions; Particle size; Sediment;
Concentration; Reflectance; Responses; Prediction; Models;
Turbidity; Water quality; Equations; Remote sensing
66 NAL Call. No.: TD403.G7
Effects of waste-water irrigation on aqueous geochemistry near
Paris, Texas. Tedaldi, D.J.; Loehr, R.C.
Dublin, Ohio : Ground Water Pub. Co; 1992 Sep.
Ground water v. 30 (5): p. 709-719; 1992 Sep. Includes
references.
Language: English
Descriptors: Texas; Waste water; Irrigation; Long term
experiments; Groundwater; Water quality; Soil chemistry;
Geochemistry; Prediction; Thermodynamics; Equilibrium; Models;
Aquifers; Saline water; Recharge; Infiltration; Hydraulic
conductivity
67 NAL Call. No.: TD420.A1E5
Elution of aged and freshly added herbicides from a soil.
Pignatello, J.J.; Ferrandino, F.J.; Huang, L.Q.
Washington, D.C. : American Chemical Society; 1993 Aug.
Environmental science & technology v. 27 (8): p. 1563-1571;
1993 Aug. Includes references.
Language: English
Descriptors: Connecticut; Soil pollution; Herbicide residues;
Atrazine; Metolachlor; Leaching; Profiles; Models
68 NAL Call. No.: S539.5.J68
Environmental and economic impacts of pesticide and irrigation
practices: EPIC-PST simulation.
Sabbagh, G.J.; Norris, P.E.; Geleta, S.; Bernado, D.J.;
Elliott, R.L.; Mapp, H.P.; Stone, J.F.
Madison, Wis. : American Society of Agronomy; 1992 Jul.
Journal of production agriculture v. 5 (3): p. 312-317; 1992
Jul. Includes references.
Language: English
Descriptors: Oklahoma; Groundwater pollution; Crop management;
Environmental impact; Economic impact; Pest control;
Irrigation; Computer techniques; Simulation models;
Pesticides; Movement in soil; Runoff
69 NAL Call. No.: 292.8 W295
Estimating changes in recreational fishing participation from
national water quality policies.
Ribaudo, M.O.; Piper, S.L.
Washington, D.C. : American Geophysical Union; 1991 Jul.
Water resources research v. 27 (7): p. 1757-1763; 1991 Jul.
Includes references.
Language: English
Descriptors: Water quality; Water policy; Water pollution;
Angling; Participation; Estimation; Models
Abstract: The complete evaluation of the offsite effects of
national policies or programs that affect levels of
agricultural nonpoint source pollution requires linking
extensive water quality changes to changes in recreational
activity. A sequential decision model is specified to describe
an individual's decisions about fishing. A participation model
for recreational fishing that includes a water quality index
reflecting regional water quality is developed and estimated
as a logit model with national level data. A visitation model
for those who decide to fish that also includes the water
quality index is estimated using ordinary least squares. The
water quality index is found to be significant in the
participation model but not in the visitation model. Together,
the two models provide a means of estimating how changes in
water quality might influence the number of recreation days
devoted to fishing. The model is used to estimate changes in
fishing participation for the Conservation Reserve Program.
70 NAL Call. No.: TC401.W27
Estimating low flow characteristics in ungauged catchments.
Nathan, R.J.; McMahon, T.A.
Dordrecht : Kluwer Academic Publishers; 1992.
Water resources management v. 6 (2): p. 85-100; 1992.
Includes references.
Language: English
Descriptors: New South Wales; Victoria; Watersheds; Rural
areas; Flow; Characteristics; Water yield; Rain; Runoff;
Models; Multivariate analysis; Climatic factors; Hydrological
data; Equations
71 NAL Call. No.: 292.8 J82
Estimating transport parameters at the grid scale: on the
value of a single measurement.
Beven, K.J.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1993 Mar01.
Journal of hydrology v. 143 (1/2): p. 109-123; 1993 Mar01.
Special Issue: Modelling Flow and Transport in the Unsaturated
Zone: Scale Problems and Spatial Variability. Includes
references.
Language: English
Descriptors: Solutes; Transport processes; Soil water; Flow;
Spatial variation; Hydrodynamic dispersion; Prediction;
Estimation; Probabilistic models
Abstract: Distributed models of solute transport at the field
and catchment scales require the specification of effective
parameters at the model grid scale. The grid scale will
generally be much larger than the scale at which it is
possible to make measurements to derive parameter values but
may be of the same order as the scale of variability of such
'point' values. In addition, measurements are usually
expensive and time consuming to make and where, for example,
'undisturbed' soil cores are used, may be destructive. This
paper describes a conditional probability based approach for
estimating grid scale effective parameter values in the light
of expected spatial heterogeneity, given only one or a small
number of available measurements. Initial results show,
somewhat surprisingly, that despite the integrative nature of
the spatial averaging involved in moving to the grid scale,
the variance of the effective grid element values does not
decrease. There is a small shift in the location of the
distribution, as a result of the macrodispersive effect of the
grid scale variability.
72 NAL Call. No.: GB746.W33
Estimation of possible anthropogenic changes in the runoff and
removal of biogenic elements from small watersheds of the
forest zone on the basis of a mathematical model.
Kondrat'ev, S.A.
New York, N.Y. : Consultants Bureau; 1991 Mar.
Water resources v. 17 (3): p. 240-248; 1991 Mar. Tranlated
from: Vodnye Resursy, V. 17, No. 3, May/June 1990, p. 24-32.
(GB746.V55). Includes references.
Language: English; Russian
Descriptors: U.S.S.R.in europe; Rsfsr; Runoff water; Sediment;
Formation; Water pollution; Nutrients; Removal; Phosphorus;
Nitrogen; Agricultural production; Effects; Watersheds;
Forests; Hydrology; Mathematical models
73 NAL Call. No.: 292.8 J82
Evaluating the green and ampt infiltration parameter values
for tilled and crusted soils.
Mohamoud, Y.M.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1991 Feb.
Journal of hydrology v. 123 (1/2): p. 25-38; 1991 Feb.
Includes references.
Language: English
Descriptors: Illinois; Agricultural soils; Rain; Infiltration;
Soil water content; Runoff; Surface layers; Tillage; Crop
residues; Crusts; Permeability; Capillary rise; Wetting front;
Hydraulic conductivity; Mathematical models; Green and ampt
equation
Abstract: Methods for determining Green-Ampt infiltration
parameter values for tilled and crusted soils are not well
established. A two-stage method is developed to determine the
Green and Ampt parameter values for soils under different
management practices. The first stage is aimed at calculating
rainfall infiltration from rainfall and runoff data of small
field plots which had different soil surface conditions (e.g.
tillage, residue cover and crusting). To determine accurate
rainfall infiltration rates from field plots, we employed a
water balance model which accounted for depression storage,
detention storage as well as surface routing of runoff. The
second stage is aimed at evaluating the values of the Green
and Ampt infiltration equation parameters by the linear least
squares parameter estimation technique. The Green and Ampt
parameter values determined were the effective capillary
suction at the wetting front and the effective hydraulic
conductivity. The results of this study indicated that this
procedure is sufficiently sensitive to reflect the effects of
tillage, residue cover and crusting on infiltration data.
Raindrop impact reduced infiltration rates by crusting the
soil surface. However, most of the management systems that
left about 30% of residue cover protected the soil from
raindrop impact as evidenced by the higher effective hydraulic
conductivity. It is concluded that the model developed by
Green and Ampt in 1911 satisfactorily fitted the infiltration
data obtained from protected and crusted soil profiles. Also,
residue cover and crusting greatly influenced the Green and
Ampt infiltration parameter values.
74 NAL Call. No.: TP995.A1I5
Evaluating transport of organic chemicals in soil resulting
from underground fuel tank leaks.
Lee, D.Y.; Chang, A.C.
Chelsen, Mich. : Lewis Publishers; 1992.
Proceedings of the Industrial Waste Conference (46): p.
131-140; 1992. Meeting held May 14-16, 1991, West Lafayette,
Indiana. Includes references.
Language: English
Descriptors: Polluted soils; Soil pollution; Organic
compounds; Petroleum; Petroleum hydrocarbons; Transport
processes; Fuel tanks; Leakage; Underground storage;
Simulation models; Equations; Mathematics; Groundwater
pollution; Soil water movement; Movement in soil
75 NAL Call. No.: GB701.W375 no.91-4142
Evaluation of a ground-water flow and transport model of the
upper Coachella Valley, California.. Evaluation of a ground
water flow and transport model of the upper Coachella Valley,
California
Reichard, Eric George; Meadows, J. Kevin
Geological Survey (U.S.),California Regional Water Quality
Control Board--Colorado River Basin Region
Sacramento, Calif. : U.S. Geological Survey ; Denver, CO :
Books and Open-File Reports Section [distributor],; 1992.
vi, 101 p. : ill., maps ; 28 cm. (Water-resources
investigations report ; 91-4142). Includes bibliographical
references (p. 42).
Language: English
Descriptors: Groundwater flow; Water, Underground
76 NAL Call. No.: TD426.J68
Evaluation of a pesticide mobility index: impact of recharge
variation and soil profile heterogeneity.
Kleveno, J.J.; Loague, K.; Green, R.E.
Amsterdam : Elsevier; 1992 Oct.
Journal of contaminant hydrology v. 11 (1/2): p. 83-99; 1992
Oct. Includes references.
Language: English
Descriptors: Hawaii; Soil pollution; Pesticides; Profiles;
Movement in soil; Attenuation; Leaching; Assessment;
Simulation models; Errors; Movement to roots; Rain
77 NAL Call. No.: 290.9 AM32T
Evaluation of fluvial sediment transport equations for
overland flow. Guy, B.T.; Dickinson, W.T.; Rudra, R.P.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 Mar. Transactions of the ASAE v. 35 (2): p.
545-555. ill; 1992 Mar. Includes references.
Language: English
Descriptors: Geological sedimentation; Overland flow; Rain;
Runoff; Splash erosion; Simulation models
Abstract: Sediment transport capacity was measured under a
range of conditions in two types of overland flow: shallow
uniform flow in the absence of rainfall, and shallow flow
affected by rainfall impact. The abilities of six fluvial
sediment transport equations to represent each dataset are
evaluated. For both flow types, common aspects of equation
performance include poor representation of sediment transport
thresholds, underprediction of transport rates, and
significant scatter about measured values. These problems,
particularly the equations' inability to predict transport
threshold, are more evident with the rain-impacted now data.
Only the Schoklitsch equation is suitable for uniform overland
flow without rain-impact, and none am suitable for rain-
impacted overland flow.
78 NAL Call. No.: 290.9 AM32T
Evaluation of PRZM and LEACHMP on intact soil columns.
Smith, W.N.; Prasher, S.O.; Barrington, S.F.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 Nov. Transactions of the ASAE v. 34 (6): p.
2413-2420; 1991 Nov. Includes references.
Language: English
Descriptors: Atrazine; Computer simulation; Leaching; Soil
properties; Water pollution
Abstract: Limiting factors towards the utilization of
pesticide transport models are lack of both detailed data and
cognizant personnel available to test and validate model
predictions. In this study, computer simulations were carried
out to test the performance of PRZM (a management model) and
LEACHMP (a research model) on leaching characteristics of
atrazine in long intact soil columns. Also, in an attempt to
evaluate model uncertainty, a sensitivity analysis of several
parameters for each model was considered. LEACHMP was found to
be superior in predicting hydrological characteristics in the
soil columns as compared to PRZM which required calibration.
Both models underestimated levels of atrazine near the soil
surface and in the leachate (115 cm depth) and over-estimated
them throughout most of the range in-between. Inaccurate
predictions for the two models are attributed to simplistic
linear adsorption equations and lack of a macropore flow
subroutine. In increasing order, PRZM was most sensitive to
rate of application, distribution coefficient, bulk density
and field capacity, whereas LEACHMP was sensitive to rate of
application, organic carbon distribution coefficient, air
entry value, and bulk density.
79 NAL Call. No.: 292.8 J82
Evaluation of the accuracy and precision of annual phosphorus
load estimates from two agricultural basins in Finland.
Rekolainen, S.; Posch, M.; Kamari, J.; Ekholm, P.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1991 Nov.
Journal of hydrology v. 128 (1/4): p. 237-255; 1991 Nov.
Includes references.
Language: English
Descriptors: Finland; Agricultural land; Drainage; Runoff;
Pollution; Phosphorus; Transport processes; Flow; Estimates;
Sampling; Frequency; Monitoring; Mathematical models;
Comparisons
Abstract: The accuracy and precision of phosphorus load
estimates from two agricultural drainage basins in western
Finland were evaluated, based on continuous flow measurements
and frequent flow-proportional sampling of total phosphorus
concentration during a 2 year period. The objective was to
compare different load calculation methods and to evaluate
alternative sampling strategies. An hourly data set of
concentrations was constructed by linear interpolation, and
these data were used in Monte Carlo runs for producing
replicate data sets for calculating the accuracy and precision
of load estimates. All estimates were compared with reference
values computed from the complete hourly data sets. The load
calculation methods based on summing the products of regularly
sampled flows and concentrations produced the best precision,
whereas the best accuracy was achieved using methods based on
multiplying annual flow by flow-weighted annual mean
concentration. When comparing different sampling strategies,
concentrating sampling in high runoff periods (spring and
autumn) was found to give better accuracy and precision than
strategies based on regular interval sampling throughout the
year. However, the best result was obtained by taking samples
flow-proportionally within the highest peak flows plus
additional regular interval (e.g. biweekly) samples outside
these flow peaks. Using this strategy, which calls for
automatic sampling equipment, accuracies better than 5% and
precisions better than 10% can be achieved with only 30-50
samples per year.
80 NAL Call. No.: 290.9 AM32T
Evaluation of the hydrologic component of the ADAPT water
table management model.
Chung, S.O.; Ward, A.D.; Schalk, C.W.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 Mar. Transactions of the ASAE v. 35 (2): p.
571-579; 1992 Mar. Includes references.
Language: English
Descriptors: Tile drainage; Water management; Water table;
Evapotranspiration; Hydrology; Macropore flow; Runoff;
Seepage; Simulation models
Abstract: A subsurface, water table management model ADAPT
(Agricultural Drainage and Pesticide Transport) has been
developed by combining drainage and subirrigation algorithms
from DRAINMOD with the GLEAMS model. In addition, the model
incorporates improved snow melt and runoff algorithms,
macropore flow due to cracking, and deep seepage. Theory for
the hydrologic components of the model is presented together
with an evaluation of the model using data from a long-term
field experiment at Castalia in North Central Ohio. Predicted
surface runoff, subsurface drainage, and combined surface and
subsurface drainage are compared with the field observations.
In general, the model predictions are within the range of the
variations of the observed replications. Sensitivity analysis
shows that surface runoff estimates are sensitive to changes
in curve number, while subsurface drainage flows are sensitive
to deep seepage estimates. Model input requirements are not
excessive and the model gives reasonable estimates of the
hydrologic component of water table management systems. ADAPT
can be used in designing water table management systems and
does not require extensive calibration. The pesticide
component of ADAPT is currently being evaluated and
development of a nutrient component has been initiated.
81 NAL Call. No.: 4 AM34P
Evaluation of the nitrogen submodel of CERES-maize following
legume green manure incorporation.
Bowen, W.T.; Jones, J.W.; Carsky, R.J.; Quintana, J.O.
Madison, Wis. : American Society of Agronomy; 1993 Jan.
Agronomy journal v. 85 (1): p. 153-159; 1993 Jan. Includes
references.
Language: English
Descriptors: Simulation models; Prediction; Nutrient uptake;
Nitrogen; Green manures; Nutrient availability;
Mineralization; Leaching; Nitrate; Losses from soil; Nitrogen
balance
Abstract: Crop simulation models that accurately predict the
availability of N from decomposing plant residues would
provide a powerful tool for evaluating legume green manures as
potential N sources for nonlegume crops. Using measured data
from a series of field experiments conducted on an Oxisol in
central Brazil, we conducted this study to test the N submodel
of CERES-Maize for its ability to simulate N mineralization,
nitrate leaching, and N uptake by maize (Zea Mays L.)
following the incorporation of 10 different legume green
manures. Legume or weed residue N at the time of incorporation
varied from 25 to 300 kg ha-1 with C/N ratios varying from 13
to 37. Comparison of predicted and measured accumulation of
inorganic N in uncropped soil showed that the model usually
provided a realistic simulation of legume N release, although
N release was overpredicted for some legumes. For all legumes,
both simulated and measured data showed that about 60% of the
organic N applied was recovered as inorganic N within 120 to
150 d after incorporation. To realistically simulate N
availability when rainfall was excessive, we modified the
model to account for delayed leaching due to nitrate retention
in the subsoil. Nitrogen uptake by maize was generally
overpredicted at high levels of available N. The N submodel
was shown to realistically simulate legume N release, but
further work is needed to determine the importance of subsoil
nitrate retention in other soils and how best such retention
might be described in the model.
82 NAL Call. No.: 290.9 AM32T
An evaluation of unit stream power theory for estimating soil
detachment and sediment discharge from tilled soils.
McIsaac, G.F.; Mitchell, J.K.; Hummel, J.W.; Elliot, W.J. St.
Joseph, Mich. : American Society of Agricultural Engineers;
1992 Mar. Transactions of the ASAE v. 35 (2): p. 535-544; 1992
Mar. Includes references.
Language: English
Descriptors: Illinois; Water erosion; Aggregates; Runoff;
Sediment yield; Simulation models; Soil properties; Streams;
Tillage
Abstract: Unit Stream Power (USP) and the associated Yang
(1973) sediment transport equations were compared to soil
detachment rates and sediment concentrations in runoff from
eroding soils. Although USP was significantly correlated with
rill detachment rates, potential energy dissipation rate per
unit rill area was a better predictor of soil detachment
rates. The Yang (1973) equations estimated sediment
concentrations within a factor of 10 of the observed
concentrations, if the median soil aggregate diameter was
within the range of diameters used by Yang to estimate the
equation parameters. When median aggregate sizes were less
than 0.15 mm, the lower limit of Yang's (1973) calibration
range, the equations tended to produce unrealistically large
estimates of sediment concentration.
83 NAL Call. No.: ViBlbVLD5655.V856 1992.J663
Evaluation of water distribution system monitoring using
stochastic dynamic modeling.
Jones, Philip Edward James,
1992; 1992.
xiv, 215 leaves : ill. ; 28 cm. Vita. Abstract.
Bibliography: leaves 181-191.
Language: English
Descriptors: Water quality management; Water
84 NAL Call. No.: 56.8 SO3
Exit condition for miscible displacement experiments.
Parlange, J.Y.; Starr, J.L.; Van Genuchten, M.Th; Barry, D.A.;
Parker, J.C. Baltimore, Md. : Williams & Wilkins; 1992 Mar.
Soil science v. 153 (3): p. 165-171; 1992 Mar. Includes
references.
Language: English
Descriptors: Transport processes; Solutes; Soil solution; Soil
analysis; Mathematical models; Determination; Convection;
Dispersion; Length; Movement in soil; Kinetics
85 NAL Call. No.: 56.8 SO3
Experimental and simulated B transport in soil using a
multireaction model. Mansell, R.S.; Bloom, S.A.; Burgoa, B.;
Nkedi-Kizza, P.; Chen, J.S. Baltimore, Md. : Williams &
Wilkins; 1992 Mar.
Soil science v. 153 (3): p. 185-194; 1992 Mar. Includes
references.
Language: English
Descriptors: Florida; Spodosols; Acid soils; Sandy soils; B
horizons; Subsurface layers; Phosphorus; Movement in soil;
Transport processes; Soil water movement; Determination;
Laboratory methods; Simulation models; Mathematical models;
Sorption; Kinetics; Sorption isotherms; Comparisons; Fixation;
Soil organic matter; Aluminum oxide; Iron oxides
86 NAL Call. No.: HC79.E5E5
Exploring the effects of multiple management objectives and
exotic species on Great Lakes food webs and contaminant
dynamics.
Fontaine, T.D.; Stewart, D.J.
New York, N.Y. : Springer-Verlag; 1992 Mar.
Environmental management v. 16 (2): p. 225-229; 1992 Mar.
Includes references.
Language: English
Descriptors: Fishery management; Lakes; Water quality; Food
chains; Objectives; Simulation models
87 NAL Call. No.: S539.5.J68
Farm-level economic and environmental impacts of eastern Corn
Belt cropping systems.
Foltz, J.C.; Lee, J.G.; Martin, M.A.
Madison, WI : American Society of Agronomy, c1987-; 1993 Apr.
Journal of production agriculture v. 6 (2): p. 290-296; 1993
Apr. Includes references.
Language: English
Descriptors: Corn belt states of U.S.A.; Cabt; Zea mays;
Medicago sativa; Glycine max; Microeconomic analysis; Economic
impact; Alternative farming; Environmental impact; Rotations;
Continuous cropping; Simulation models; Computer simulation;
Erosion; Runoff; Pesticides; Water pollution
88 NAL Call. No.: TD201.A4 A
fast and accurate method for solving subsurface contaminant
transport problems with a single uncertain parameter.
Ahlfeld, D.P.; Pinder, G.F.
Essex : Elsevier Science Publishers Ltd; 1992.
Advances in water resources v. 15 (2): p. 143-150; 1992.
Includes references.
Language: English
Descriptors: Groundwater pollution; Contaminants; Transport;
Equations; Random sampling; Stochastic models; Groundwater
flow; Hydraulic conductivity
89 NAL Call. No.: QH545.A1E58
Fate, dissipation and environmental effects of pesticides in
southern forests: a review of a decade of research progress.
Neary, D.G.; Bush, P.B.; Michael, J.L.
Tarrytown, N.Y. : Pergamon Press; 1993 Mar.
Environmental toxicology and chemistry v. 12 (3): p. 411-428;
1993 Mar. Paper presented at the "Symposium on Pesticides in
Forest Management, 11th Annual Meeting of the Society of
Environmental Toxicology and Chemistry," November 11-15, 1990,
Arlington, Virginia. Literature review. Includes references.
Language: English
Descriptors: Southern states of U.S.A.; Pesticides; Forestry;
Ecosystems; Watersheds; Environmental impact; Water quality;
Air quality; Groundwater pollution; Silviculture; Species
diversity; Simulation models; Nontarget effects; Literature
reviews
90 NAL Call. No.: QH540.N3
Fate of non-aqueous phase liquids: modeling of surfactant
effects. Harwell, J.H.; Sabatini, D.A.; Soerens, T.S.
Berlin, W. Ger. : Springer-Verlag; 1993.
NATO ASI series : Series G : Ecological sciences v. 32: p.
309-328; 1993. In the series analytic: Migration and fate of
pollutants in soils and subsoils / edited by D. Petruzzelli
and F.G. Helfferich. Proceedings of the NATO Advanced Study
Institute, May 24-June 5, 1992, Maratea, Italy. Includes
references.
Language: English
Descriptors: Soil pollution; Groundwater pollution;
Pollutants; Organic compounds; Transport processes;
Groundwater flow; Soil water movement; Equations; Mathematics
91 NAL Call. No.: TP963.A1F4
Fertilization under drip irrigation.
Bar-Yosef, B.
New York, N.Y. : Marcel Dekker; 1991.
Fertilizer science and technology series v. 7: p. 285-329;
1991. In the series analytic: Fluid fertilizer science and
technology / edited by D.A. Palgrave. Includes references.
Language: English
Descriptors: Fertigation; Liquid fertilizers; Fluids; Trickle
irrigation; Fertilizer requirement determination; Irrigation
water; Ph; Salinity; Plant nutrition; Nutrient requirements;
Nutrient uptake; Temporal variation; Nitrogen; Movement in
soil; Transport processes; Spatial distribution; Root systems;
Soil water content; Soil solution; Mathematical models;
Monitoring; Fertilizer technology; Management; Crop production
92 NAL Call. No.: QD1.A45
Field and model estimates of pesticide runoff from turfgrass.
Rosenthal, W.D.; Hipp, B.W.
Washington, D.C. : The Society; 1993.
ACS Symposium series - American Chemical Society (522): p.
208-213; 1993. In the series analytic: Pesticides in urban
environments: Fate and significance / edited by K.D. Racke and
A.R. Leslie. Paper presented at the 203rd National Meeting of
the American Chemical Society, April 5-10, 1992, San
Francisco, California. Includes references.
Language: English
Descriptors: Chlorpyrifos; Carbaryl; Diazinon; 2,4-d; Dicamba;
Atrazine; Fertilizers; Herbicide residues; Insecticide
residues; Runoff water; Mathematical models; Simulation
models; Cynodon dactylon; Buchloe dactyloides
Abstract: Environmental awareness of surface runoff water
quality is increasing. A study was conducted to analyze the
impact of different turfgrass fertilizer and pesticide
management systems on runoff water quality. A hydrologic and
water quality model, Erosion Productivity Impact Calculator
(EPIC), was used to estimate pesticide and nutrient
concentrations in runoff from turfgrass on a Houston Black
Clay. Nutrient and pesticide concentrations in the surface
runoff increased significantly for highly maintained turfgrass
systems. A larger fraction of the amount applied was observed
in runoff for the moderate application rate treatments.
Simulated results are being validated from measured runoff of
turfgrass plots at Dallas, TX.
93 NAL Call. No.: S478.S68T43 no.31
Field measurement and modelling of runoff and erosion response
of small agricultural catchments in the mid north of South
Australia. Punthakey, J.F.
Adelaide, South Australia : Dept. of Agriculture,; 1992.
v, 137 p. : ill. ; 30 cm. (Technical paper (South Australia.
Dept. of Agriculture) ; no. 31.). May 1992. AGDEX 572.
Includes bibliographical references (p. 134-137) and index.
Language: English
94 NAL Call. No.: 56.9 SO3
Field study of bromacil transport under continuous-flood
irrigation. Jaynes, D.B.
Madison, Wis. : The Society; 1991 May.
Soil Science Society of America journal v. 55 (3): p. 658-664;
1991 May. Includes references.
Language: English
Descriptors: Bromacil; Flood irrigation; Herbicide residues;
Leaching; Movement in soil; Transport processes; Agricultural
soils; Mathematical models
Abstract: The transport processes of sorbing chemicals in
field soils are poorly understood. This study characterized
the leaching behavior of the weakly sorbing herbicide bromacil
(5-bromo-3-sec-butyl-6-methyluracil) in comparison to Br-
during continuous-flood irrigation of a small field plot.
Twenty-four solution samplers were used to periodically
collect in situ samples from seven depths within four 1.83 by
1.83 m subplots. Estimates of the pore water velocity (vs) and
dispersion coefficient (D) were made by fitting an analytical
solution of the convection-dispersion (CD) equation to the Br-
data. Estimates of retardation (R) were made by fitting the CD
equation to the bromacil data using the vs and D estimates
from the Br- data and letting R be a fitting parameter.
Estimates of R were also made from the results of batch
equilibration studies using soil from seven depths. Best-fit
vs and D values exhibited considerable variability from
sampler to sampler (CV = 1.25 and 1.30, respectively) and
showed no significant trends with depth. Retardation values
estimated from the CD equation averaged 1.88, but varied from
1.21 to 3.35 and also showed no significant trend with depth.
In contrast, batch equilibration studies showed the absorption
properties of the surface 0.6 m of soil to be significantly
different than the 0.6- to 3-m depth, with R values decreasing
from 1.62 for the surface 0.6 m to 1.31 at 3 m. Although the
two methods gave the same estimate of R in the surface soil
neither the lower R values at deeper depths nor the tendency
to decrease with depth as predicted from the batch studies was
apparent in the transport data. Using D as an additional
fitting parameter to the bromacil data resulted in an average
increase of 1.96 for this parameter, indicating more
dispersion for the sorbing solute. Increased dispersion and
increased tailing of the sorbed solute may be attributed to
spatially variable adsorption and to a negative correlation
between vs and R (r = -0.524)
95 NAL Call. No.: 290.9 AM32T
Field testing and comparison of the PRZM and GLEAMS models.
Smith, M.C.; Bottcher, A.B.; Campbell, K.L.; Thomas, D.L. St.
Joseph, Mich. : American Society of Agricultural Engineers;
1991 May. Transactions of the ASAE v. 34 (3): p. 838-847; 1991
May. Includes references.
Language: English
Descriptors: Georgia; Alachlor; Atrazine; Bromides; Field
tests; Leaching; Groundwater; Pesticides; Precipitation;
Runoff; Simulation models; Soil properties; Soil water
Abstract: The root/vadose zone transport models PRZM and
GLEAMS were tested against an experimental data set.
Parameters were not optimized or calibrated to produce the
best fit. In all cases the measured and predicted peak
concentrations agreed within an order of magnitude, and in
most cases agreed within a factor of 2 to 3. This level of
agreement between the models and the measured data is within
the criteria for model acceptance suggested by the EPA. The
small differences noted in simulated transport between the
models are thought to be a result of differences in
computational layering and chemical transport calculation
methods.
96 NAL Call. No.: TD426.J68
Fluid flow and solute transport processes in unsaturated
heterogeneous soils: Preliminary numerical experiments.
Liu, C.C.K.; Loague, K.; Feng, J.S.
Amsterdam : Elsevier; 1991 Feb.
Journal of contaminant hydrology v. 7 (3): p. 261-283; 1991
Feb. Includes references.
Language: English
Descriptors: Movement in soil; Pollutants; Unsaturated flow;
Mathematical models; Finite element analysis; Prediction;
Aquifers
97 NAL Call. No.: S539.5.J68
Functional form selection for regional crop response to
salinity, water application, and climate.
Lee, D.J.
Madison, Wis. : American Society of Agronomy; 1992 Oct.
Journal of production agriculture v. 5 (4): p. 445-454; 1992
Oct. Includes references.
Language: English
Descriptors: Zea mays; Sorghum bicolor; Triticum aestivum;
Triticum turgidum; Irrigation; Application rates; Saline
water; Water quality; Mathematical models; Crop yield; Soil
salinity; Climatic factors
98 NAL Call. No.: QH540.J6 A
functional model of solute transport that accounts for bypass.
Corwin, D.L.; Waggoner, B.L.; Rhoades, J.D.
Madison, Wis. : American Society of Agronomy; 1991 Jul.
Journal of environmental quality v. 20 (3): p. 647-658; 1991
Jul. Includes references.
Language: English
Descriptors: Groundwater; Water quality; Transport processes;
Solutes; Water management; Mathematical models
Abstract: Public awareness of groundwater contamination has
created renewed interest in solute transport models that can
be practically applied as groundwater quality management
tools. Because of their simplicity with regard to input
requirements, functional models of solute transport are
excellent groundwater quality management tools. A functional
model of one-dimensional solute transport that accounts for
hydraulic bypass is presented. The transport model TETrans,
simulates the vertical movement of nonvolatile solutes (i.e.,
trace elements and nonvolatile organic chemicals) through the
vadose zone. Plant water uptake is taken into account assuming
no solute uptake by the plant. TETrans requires minimal input
data for its operation. Since TETrans uses a mass-balance
approach to solute transport, it offers the speed of an
analytical solution and the versatility of a numerical
approach without the need for input parameters, which are
difficult to measure. TETrans is able to account for bypass
with a single term, the mobility coefficient. The mobility
coefficient, gamma, represents the fraction of the soil liquid
phase, which is subject to piston-type displacement;
therefore, 1 - gamma represents the fraction of the liquid
phase that is bypassed. The mobility coefficient is a
temporally and spatially variable parameter (within a range of
0 to l) which is calculated from the deviation of the measured
chloride concentration from the predicted concentration
assuming piston displacement and assuming complete mixing of
the resident soil solution and incoming water for a given
irrigation and volume of soil. A constant mobility coefficient
for a given depth or entire profile can be determined by
averaging temporally varying mobility coefficients or
averaging spatially and temporally varying mobility
coefficients, respectively. In essence, the mobility
coefficient simplistically accounts for three physical
transport phenomena in a single term. On a microscopic level
there is flow thr
99 NAL Call. No.: 290.9 AM32T
Generic anaerobic digestion model for the simulation of
various reactor types and substrates.
Thomas, M.V.; Nordstedt, R.A.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1993 Mar. Transactions of the ASAE v. 36 (2): p.
537-544; 1993 Mar. Literature review. Includes references.
Language: English
Descriptors: Florida; Agricultural wastes; Animal wastes;
Hyacinths; Manures; Straw; Waste disposal; Anaerobic
digestion; Literature reviews; Mathematical models; Methane
production
Abstract: A mathematical model was developed to represent a
wide variety of anaerobic reactor types and substrates. The
model is a generic, anaerobic digestion process model, using
lumped substrate parameters, and was developed for use as
type-specific reactor model operating within the sphere of a
larger system model. Three types of anaerobic reactors were
simulated: fixed-bed reactors, conventional stirred tank
reactors, and continuously expanding reactors. The generic
anaerobic digestion model provided a tool for testing various
values of conversion efficiency and kinetic parameters for a
wide range of substrate types and reactor designs.
100 NAL Call. No.: 292.8 W295 A
geochemical transport model for redox-controlled movement of
mineral fronts in groundwater flow systems: a case of nitrate
removal by oxidation of pyrite. Engesgaard, P.; Kipp, K.L.
Washington, D.C. : American Geophysical Union; 1992 Oct.
Water resources research v. 28 (10): p. 2829-2843; 1992 Oct.
Includes references.
Language: English
Descriptors: Denmark; Groundwater flow; Transport processes;
Denitrification; Pyrites; Oxidation; Nitrate; Reduction; Redox
reactions; Geochemistry; Spatial distribution; Algorithms;
Mathematical models; Simulation
Abstract: A one-dimensional prototype geochemical transport
model was developed in order to handle simultaneous
precipitation-dissolution and oxidation-reduction reactions
governed by chemical equilibria. Total aqueous component
concentrations are the primary dependent variables, and a
sequential iterative approach is used for the calculation. The
model was verified by analytical and numerical comparisons and
is able to simulate sharp mineral fronts. At a site in
Denmark, denitrification has been observed by oxidation of
pyrite. Simulation of nitrate movement at this site showed a
redox front movement rate of 0.58 m yr-1, which agreed with
calculations of others. It appears that the sequential
iterative approach is the most practical for extension to
multidimensional simulation and for handling large numbers of
components and reactions. However, slow convergence may limit
the size of redox systems that can be handled.
101 NAL Call. No.: 56.9 SO32
Geographic information system for differentiating unused
wells. Tan, Y.R.; Shih, S.F.
S.l. : The Society; 1991.
Proceedings - Soil and Crop Science Society of Florida v. 50:
p. 110-116; 1991. Paper presented at the "Symposium on
Reality of Sustainable Agriculture in Florida, September
26-28, 1990, Daytona Beach, FLorida. Includes references.
Language: English
Descriptors: Florida; Groundwater; Wells; Water management;
Geographical distribution
102 NAL Call. No.: QE1.E5
Geostatistical modeling of salinity as a basis for irrigation
management and crop selection--a case study in central
Tunisia.
Soderstrom, M.
New York, N.Y. : Springer; 1992 Sep.
Environmental geology and water sciences v. 20 (2): p. 85-92;
1992 Sep. Includes references.
Language: English
Descriptors: Tunisia; Groundwater; Saline water; Irrigation
water; Spatial distribution; Soil salinity; Irrigated soils;
Wells; Water; Soil; Sampling; Maps; Leaching; Models;
Irrigation scheduling; Crop yield; Yield losses; Crops;
Selection
103 NAL Call. No.: QH541.5.D4J6 A
GIS approach to desertification assessment and mapping.
Grunblatt, J.; Ottichilo, W.K.; Sinange, R.K.
London : Academic Press; 1992 Jul.
Journal of arid environments v. 23 (1): p. 81-102; 1992 Jul.
Includes references.
Language: English
Descriptors: Kenya; Desertification; Remote sensing; Satellite
imagery; Models; Geography
104 NAL Call. No.: S671.A66
GIS-assisted input data set development for the Finite Element
Storm Hydrograph Model (FESHM).
Wolfe, M.L.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 Mar. Applied engineering in agriculture v. 8
(2): p. 221-227; 1992 Mar. Includes references.
Language: English
Descriptors: Hydrology; Simulation models; Automation;
Computer techniques
Abstract: A study was conducted to develop an automated
proceedings to assist in the development of input data sets
for the FESHM hydrologic model using the GRASS geographic
information system. Shell scripts (executable sequences of
commands in the UNIX operating system) were developed to
overlay soils and land use maps to generate hydrologic
response unit (HRU) maps and to compute the fractional areas
of HRUs in overland flow elements. The automated procedures
decreased the input data set development time significantly,
by approximately 250% (from five to two hours) for a 122 ha
(303 ac) watershed. The time savings on larger, more variable
watersheds would be even greater. The input data set
development procedure provides an efficient manner for
considering alternative land use and management scenarios.
105 NAL Call. No.: 292.9 AM34
Ground water quality implications of soil conservation
measures: an economic perspective.
Setia, P.; Piper, S.
Bethesda, Md. : American Water Resources Association; 1991
Mar. Water resources bulletin v. 27 (2): p. 201-208; 1991 Mar.
Includes references.
Language: English
Descriptors: Corn belt of U.S.A.; Soil conservation;
Groundwater; Water quality; Pesticides; Runoff; Leaching;
Agricultural economics; Usda; Federal programs
Abstract: An evaluation of the intermedia movement of
pesticides applied under various land management systems
already in place, or to be implemented, under the Conservation
Reserve and Conservation Compliance programs is presented. The
simulation modeling approach followed in this analysis
consists of a mathematical programming model and
leaching/surface runoff, Pesticide Root Zone Model (PRZM)
models. Special care was taken to ensure that the physical
model was sensitive to the chemical characteristics of
individual pesticides and the important physical changes
brought about by different agricultural practices. Results
show that, although these programs as now planned, increase
farm income and achieve soil conservation goals, they may
adversely affect ground water quality. Also, depending on soil
and location characteristics, there are tradeoffs between
surface and ground water quality implications. Hence, if these
programs are to address water quality problems, the
recommended practices must be evaluated for their impact on
water quality, particularly in potentially vulnerable areas.
106 NAL Call. No.: QD1.A45
Groundwater and surface water risk assessments for proposed
golf courses. Cohen, S.Z.; Durborow, T.E.; Barnes, N.L.
Washington, D.C. : The Society; 1993.
ACS Symposium series - American Chemical Society (522): p.
214-227; 1993. In the series analytic: Pesticides in urban
environments: Fate and significance / edited by K.D. Racke and
A.R. Leslie. Paper presented at the 203rd National Meeting of
the American Chemical Society, April 5-10, 1992, San
Francisco, California. Includes references.
Language: English
Descriptors: Hawaii; Massachusetts; Golf courses; Golf green
soils; Herbicide residues; Insecticide residues; Leaching;
Leachates; Runoff; Surface water; Water pollution; Groundwater
pollution; Mathematical models; Simulation models; Risk;
Fungicides; Pesticide residues; Fertilizers; Nitrogen
Abstract: Proposed golf course developments usually require
environmental impact statements in the U.S. Concerns about
ground water, surface water, and near-shore coastal water
quality and wetlands often require state-of-the-art risk
assessments and complex computerized simulation modeling. It
is extremely important to obtain site-specific data for these
risk assessments. Thus soil sampling, test borings, stream
surveys, and coastal surveys are often done. Daily weather
records are obtained or generated. The new PRZM-VADOFT model
pair is used for leaching assessments, even though nonlinear
adsorption isotherms cannot be used. The SWRRBWQ model is
difficult to use but it is appropriate for the modeling of
complex drainage patterns at the basin and sub-basin scale, as
with golf courses. Annual and storm-event runoff values are
computed for pesticides, nutrients, runoff water, and
sediments. It is best used for areas expected to experience
appreciable runoff. EXAMS II provides useful predictions of
stream water quality. An uncertainty analysis is a critical
but often overlooked part of modeling. These results help fine
tune proposed turf management programs and may indicate the
need for design changes. Risk assessments in Hawaii are
especially complex; they often indicate the need for detention
basins.
107 NAL Call. No.: TD420.A1E5
Herbicide transport in rivers: importance of hydrology and
geochemistry in nonpoint-source contamination.
Squillace, P.J.; Thurman, E.M.
Washington, D.C. : American Chemical Society; 1992 Mar.
Environmental science & technology v. 26 (3): p. 538-545; 1992
Mar. Includes references.
Language: English
Descriptors: Iowa; Minnesota; Herbicide residues; Water
pollution; River water; Groundwater pollution; Concentration;
Models; Overland flow
108 NAL Call. No.: S601.A34
High bed-low ditch system in the Pearl River Delta, South
China. Ming, L.S.; Jian, L.R.
Amsterdam : Elsevier; 1991 Jun14.
Agriculture, ecosystems and environment v. 36 (1/2): p.
101-109; 1991 Jun14. Includes references.
Language: English
Descriptors: China; Delta soils; Alluvial soils; Deltas;
Subtropics; Saccharum officinarum; Musa paradisiaca; Citrus
reticulata; Oryza sativa; Sustainability; Ditches; High water
tables; Soil depth; Roots; Growth; Erosion; Sediment;
Nutrients; Losses from soil systems; Cycling; Flow; Models;
Crop production; Agricultural byproducts; Irrigation water;
Rain; Runoff water; Drainage water; Fertilizers; Dry matter
accumulation; Decomposition; Crop residues; Nitrogen;
Phosphorus pentoxide; Potassium; Nutrient content; Temporal
variation; Dry season; Rainy season; Water quality; Organic
matter
109 NAL Call. No.: TC163.I54 1992
Hydraulic and environmental modelling--estuarine and river
waters proceedings of the Second International Conference on
Hydraulic and Environmental Modelling of Coastal, Estuarine,
and River Waters.
Falconer, R. A.; Shiono, K.; Matthew, R. G. S.
International Conference on Hydraulic and Environmental
Modelling of Coastal, Estuarine, and River Waters 2nd : 1992 :
University of Bradford. Aldershot, Hants, UK ; Brookfield, Vt.
: Ashgate,; 1992.
2 v. : ill. ; 24 cm. Proceedings of a conference held at the
University of Bradford, UK Sept. 22-24, 1992. Vol. 1 edited
by F.A. Falconer, S.N. Chandler-Wilde, S.Q. Liu. Includes
bibliographical references.
Language: English
Descriptors: Hydraulics; Water quality; Sediment transport
110 NAL Call. No.: 290.9 AM32T
Hydraulic roughness coefficients as affected by random
roughness. Gilley, J.E.; Finkner, S.C.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 May. Transactions of the ASAE v. 34 (3): p.
897-903; 1991 May. Includes references.
Language: English
Descriptors: Nebraska; Hydraulic resistance; Runoff; Surface
roughness; Tillage; Upland areas; Water flow; Simulation
models
Abstract: Random roughness parameters are used to
characterize surface microrelief. In this study, random
roughness was determined following six selected tillage
operations. Random roughness measurements agreed closely with
values reported in the literature. Surface runoff on upland
areas is analyzed using hydraulic roughness coefficients.
Darcy-Weisbach and Manning hydraulic roughness coefficients
were identified in this investigation on each soil surface
where random roughness values were determined. Hydraulic
roughness coefficients were obtained from measurements of
discharge rate and flow velocity. The experimental data were
used to derive regression relationships which related Darcy-
Weisbach and Manning hydraulic roughness coefficients to
random roughness and Reynolds number. Random roughness values
available in the literature can be substituted into the
regression equations to estimate hydraulic roughness
coefficients for a wide range of tillage implements. The
accurate prediction of hydraulic roughness coefficients will
improve our ability to understand and properly model upland
flow hydraulics.
111 NAL Call. No.: 292.8 J82
Hydrogeologic controls on peatland development in the
Malloryville Wetland, New York (USA).
McNamara, J.P.; Siegel, D.I.; Glaser, P.H.; Beck, R.M.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Dec.
Journal of hydrology v. 140 (1/4): p. 279-296; 1992 Dec.
Includes references.
Language: English
Descriptors: New York; Peatlands; Swamps; Bogs; Fens;
Hydrology; Geology; Vegetation; Plant communities; Ecology;
Surface water; Water quality; Groundwater; Groundwater flow;
Discharge; Upward movement; Mounds; Water table; Indicator
species; Simulation models
Abstract: The Malloryville Wetland Complex, a small kettle-
hole peatland, contains a diversity of peatland types. The
wetland has a 'rich' side that contains wetland vegetation
associated with solute-rich, near-neutral pH (minerotrophic)
water, and a 'poor' side containing vegetation that grows in
solute-poor and acidic (ombrotrophic) water. Vertical head
gradients at piezometer clusters located in the rich side
clearly show that groundwater is moving upwards towards the
land surface, consistent with the vegetation types and surface
water quality. In contrast, vertical head gradients also show
that groundwater is moving upward in the poor side even though
the vegetation and surface water chemistry are not
minerotrophic. An incipient raised bog in the center of the
poor side is the only site where groundwater moves
consistently downward. A peat core collected at the bog center
shows that the bog site was initially covered by minerotrophic
vegetation, typically found in groundwater discharge zones,
which was later replaced by ombrotrophic bog vegetation.
Theoretical computer simulation experiments of the bog
hydrogeologic setting through time suggest that the direction
of vertical groundwater flow at the bog site permanently
changed from up to down when a water table mound developed
under a convex-shaped fen peat mound that probably formed
because of differential peat accumulation. Ombrotrophic
conditions and bog vegetation probably began when the fen
water table mound grew sufficiently large enough to divert the
upward movement of regional groundwater. The transition from
rich to poor environments probably occurred when the wetland
water table was substantially below the elevation of the
surrounding regional water table.
112 NAL Call. No.: HD1750.W4
The impact of pollution controls on livestock--crop producers.
Schnitkey, G.D.; Miranda, M.J.
Bozeman, Mont. : Western Agricultural Economics Association;
1993 Jul. Journal of agricultural and resource economics v. 18
(1): p. 25-36; 1993 Jul. Includes references.
Language: English
Descriptors: Phosphorus; Runoff; Soil pollution; Pollution
control; Livestock enterprises; Agricultural land; Crop
production; Farmyard manure; Commercial soil additives;
Environmental policy; Livestock numbers; Application methods;
Returns; Mathematical models; Pig farming; Maize
113 NAL Call. No.: 290.9 AM32T
Impact of random data errors on parameter estimation in
hydrologic modeling. Borah, A.; Haan, C.T.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 May. Transactions of the ASAE v. 34 (3): p.
857-864; 1991 May. Includes references.
Language: English
Descriptors: Oklahoma; Hydrology; Rain; Runoff; Stream flow;
Simulation models; Water resources; Watersheds
Abstract: Parameter uncertainty in hydrologic models is due,
in part, to random errors in input data used for calibration.
This work investigates the impact of various error
distributions associated with input data on the final
estimated parameter values using three different estimation
criteria. Errors in precipitation data were found to introduce
more uncertainty into parameter estimates than errors in
runoff data. Parameter uncertainty increased as the level of
error introduced into input data increased. Correlated errors
in the input data greatly increased the uncertainty associated
with parameter estimates.
114 NAL Call. No.: 44.8 J822
Impact of Texas water quality laws on dairy income and
viability. Leatham, D.J.; Schmucker, J.F.; Lacewell, R.D.;
Schwart, R.B.; Lovell, A.C.; Allen, G.
Champaign, Ill. : American Dairy Science Association; 1992
Oct. Journal of dairy science v. 75 (10): p. 2846-2856; 1992
Oct. Includes references.
Language: English
Descriptors: Texas; Dairy farms; Dairy wastes; Water quality;
Law; Profitability; Estimated costs; Cash flow; Farm
indebtedness; Risk; Survival; Mathematical models
Abstract: A dairy waste management spreadsheet was developed
and applied along with partial budgets and whole firm, Monte
Carlo simulations for Texas dairies to evaluate the impact
that Texas water quality laws have on dairy profitability and
survival. Results showed that representative 300- and 720-cow
dairies will incur additional annual costs of $60 and $81 per
cow, respectively. Compliance with water quality laws reduces
net farm income by 27 and 63% for 720-cow dairies with low and
high debt positions, respectively. The probability of survival
of the dairies with low debt was not affected by compliance.
The probability of survival of firms with high debt positions
decreased by 47 percentage points. Under the conditions
modeled, net farm income for representative 300-cow dairies
would be negative after compliance with water quality laws.
115 NAL Call. No.: 280.8 J822
Impact targets versus discharge standards in agricultural
pollution management.
Braden, J.B.; Larson, R.S.; Herricks, E.E.
Ames, Iowa : American Agricultural Economics Association; 1991
May. American journal of agricultural economics v. 73 (2): p.
388-397; 1991 May. Includes references.
Language: English
Descriptors: Michigan; Fish; Lakes; Pollution; Losses;
Habitats; Soil movement; Case studies; Watersheds; Pesticides;
Water management; Environmental policy; Optimization;
Mathematical models
116 NAL Call. No.: S494.5.S86S8
Impacts of uncertainty on policy costs of managing nonpoint
source ground water contamination.
Halstead, J.M.; Batie, S.S.; Taylor, D.B.; Heatwole, C.D.;
Diebel, P.L.; Kramer, R.A.
Binghamton, N.Y. : Food Products Press; 1991.
Journal of sustainable agriculture v. 1 (4): p. 29-48; 1991.
Includes references.
Language: English
Descriptors: Virginia; Groundwater pollution; Nitrates;
Stochastic models; Stochastic programming; Agricultural
policy; Costs
117 NAL Call. No.: 290.9 AM32T
The importance of precise rainfall inputs in nonpoint source
pollution modeling.
Rudra, R.P.; Dickinson, W.T.; Euw, E.L. von
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1993 Mar. Transactions of the ASAE v. 36 (2): p.
445-450; 1993 Mar. Includes references.
Language: English
Descriptors: Ontario; Agricultural wastes; Losses from soil;
Models; Pollutants; Rain; Soil properties
Abstract: Rainfall data provide a prime input in nonpoint
source pollution (nps) modeling. The sensitivity of model
outputs to variations in the time step selected for rainfall
data has been explored for two nps models, a field-scale
continuous model, and an event-based watershed-scale model,
for the temperate climatic conditions of Southern Ontario,
Canada. This study has revealed that model outputs regarding
runoff, soil loss and sediment yield, and calibrated
parameters representing soil hydraulic properties and erosion
characteristics are extremely sensitive to small variations in
the rainfall time step. Model users must use caution therefore
to take these variations into account during the calibration
and application of such models.
118 NAL Call. No.: 290.9 AM32T
Infiltration and runoff simulation on a plane.
Stone, J.J.; Lane, L.J.; Shirley, E.D.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 Jan. Transactions of the ASAE v. 35 (1): p.
161-170; 1992 Jan. Includes references.
Language: English
Descriptors: Erosion; Infiltration; Kinetics; Runoff;
Simulation models; Computer software
Abstract: A program which computes infiltration and the
overland flow hydrograph on a single, homogeneous plane is
described. Infiltration is computed by the Green and Ampt
equation and the hydrograph is computed by a semi-analytical
method of characteristics solution of the kinematic wave model
for overland flow. Default parameter estimation values are
supplied by the program for both the infiltration and
hydrograph models. Use of the model as a tool for parameter
selection is illustrated with rangeland rainfall simulator
data.
119 NAL Call. No.: QH540.N3
Integrating database, spreadsheet, graphics, GIS, statistics,
simulation models and expert systems: experiences with the
RAISON system on microcomputers.
Lam, D.C.L.
Berlin, W. Ger. : Springer-Verlag; 1991.
NATO ASI series : Series G : Ecological sciences v. 26: p.
429-459; 1991. In the series analytic: Decision support
systems: Water resources planning / edited by D.P. Loucks and
J.R. da Costa. Proceedings of the NATO Advanced Research
Workshop on Computer-Aided Support Systems for Water
Resources, Research and Management, September 24-28, 1990,
Ericeira, Portugal. Includes references.
Language: English
Descriptors: Water resources; Water management; Computer
software; Computer graphics; Databases; Computer simulation;
Simulation models; Expert systems; Microcomputers
120 NAL Call. No.: HC79.P55J6
Integrating fishery and water resource management: a
biological model of a California salmon fishery.
Fisher, A.C.; Hanemann, W.M.; Keeler, A.G.
Duluth, Minn. : Academic Press; 1991 May.
Journal of environmental economics and management v. 20 (3):
p. 234-261; 1991 May. Includes references.
Language: English
Descriptors: California; Salmon; Fishery management; Water
resources; Water management; Water flow; Hatcheries;
Regulations; Water quality; Fresh water; Deltas; Dynamic
models; Populations; Trends; Simulation; Quantitative analysis
121 NAL Call. No.: QH540.N3
The interface between GIS and hydrology.
Wallis, J.R.
Berlin, W. Ger. : Springer-Verlag; 1991.
NATO ASI series : Series G : Ecological sciences v. 26: p.
189-197; 1991. In the series analytic: Decision support
systems: Water resources planning / edited by D.P. Loucks and
J.R. da Costa. Proceedings of the NATO Advanced Research
Workshop on Computer-Aided Support Systems for Water
Resources, Research and Management, September 24-28, 1990,
Ericeira, Portugal. Includes references.
Language: English
Descriptors: Water resources; Hydrology; Water management;
Computer simulation; Simulation models; Computer hardware;
Computer graphics; Computer software
122 NAL Call. No.: TD370.I575 1993
An Introduction to water quality modelling., 2nd ed..
James, A.
Chichester ; New York : Wiley,; 1993.
vi, 311 p. : ill. ; 25 cm. Includes bibliographical
references and index.
Language: English
Descriptors: Water quality; Water quality management
123 NAL Call. No.: 23 AU783
Irrigation using groundwater for watertable control: a model
of water and salt balance limitations.
Salvich, P.G.
Melbourne : Commonwealth Scientific and Industrial Research
Organization; 1992.
Australian journal of agricultural research v. 43 (1): p.
225-239; 1992. Includes references.
Language: English
Descriptors: New South Wales; Irrigation; Groundwater;
Leaching; Recharge; Salinity; Simulation models
124 NAL Call. No.: 292.8 J82
Kinematic analysis of flood runoff for a small-scale upland
field. Yomota, A.; Islam, M.N.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Aug15.
Journal of hydrology v. 137 (1/4): p. 311-326; 1992 Aug15.
Includes references.
Language: English
Descriptors: Japan; Reclamation; Runoff; Overland flow;
Flooding; Sloping land; Upland areas; Mathematical models;
Kinematics
Abstract: In Japan, many sloping fields are being reclaimed
by the Ministry of Agriculture, Forestry and Fisheries to
increase the upland field areas. To predict the flood
discharge from these fields, a study was undertaken from one
reclaimed sloping field, in the Hiroshima prefecture, with an
area of 4.55 ha. For modelling purposes, the widely used
kinematic wave equations and method of characteristics were
used. Rainfall and runoff data were collected for a period of
6 years (1984-1989) from the field, for both furrow and non-
furrow conditions and were used in these analyses. Manning,
Darcy and laminar resistance equations were used and Manning's
equation was found to be the best of the three. Manning's
roughness coefficient (n) for furrow flow and equivalent
roughness (N) for non-furrow flow conditions were determined
and are presented in tabular form. Application of the non-
furrow flow equation to the furrow flow condition required
selecting an adequate equivalent roughness. Finally,
verification of time of concentration, velocity of sheet or
furrow flow and runoff coefficient were made both for furrow
and non-furrow conditions, and these are graphically
presented.
125 NAL Call. No.: TD201.A4 A
kinematic model of infiltration and runoff generation in
layered and sloped soils.
Cabral, M.C.; Garrote, L.; Bras, R.L.; Entekhabi, D.
Essex : Elsevier Science Publishers Ltd; 1992.
Advances in water resources v. 15 (5): p. 311-324; 1992.
Includes references.
Language: English
Descriptors: Infiltration; Rain; Movement in soil; Runoff
water; Layered soils; Sloping land; Kinetics; Models
126 NAL Call. No.: 292.8 W295
Kinematic routing using finite elements on a triangular
irregular network. Goodrich, D.C.; Woolhiser, D.A.; Keefer,
T.O.
Washington, D.C. : American Geophysical Union; 1991 Jun.
Water resources research v. 27 (6): p. 995-1003; 1991 Jun.
Includes references.
Language: English
Descriptors: Overland flow; Rain; Runoff; Watersheds;
Topography; Kinematics; Mathematical models
Abstract: Automated extraction of geometry for hydraulic
routing from digital elevation models (DEM) is a procedure
that must be easily accomplished for widespread application of
distributed hydraulically based rainfall excess-runoff models.
One-dimensional kinematic routing on a regular grid DEM is
difficult due to flow division and convergence. Two-
dimensional kinematic routing on a triangular irregular
network (TIN) surmounts many of these difficulties. Because
TIN DEMs typically require far fewer points to represent
topography than regular grid DEMs, substantial computational
economy is also realized. One-dimensional routing using vector
contour data overcomes the grid-based routing disadvantages
but often requires several orders of magnitude more storage
points than a TIN. The methodology presented in this paper
represents a compromise between slightly increased
computational complexity and the economy of TIN topographic
representation. We take the unique approach of subdividing
each topographic triangle (TIN facet) into a set of coplanar
triangular finite elements, performing routing on a single
facet and then routing the resulting excess hydrograph to
downstream facets and channels via upstream boundary
conditions. Results indicate that shock conditions are readily
handled, computed depths match analytic results to within +/-
3% and volume balances are typically within 1%. This modeling
system illustrates the viability of kinematic routing over a
TIN DEM derived directly from digital mapping data.
127 NAL Call. No.: S590.S62
Kinetics of soil chemical reactions--a theoretical treatment.
Aharoni, C.; Sparks, D.L.
Madison, Wis. : Soil Science Society of America; 1991.
SSSA special publication series (27): p. 1-18; 1991. In the
series analytic: Rates of soil chemical processes / edited by
D.L. Sparks and D.L. Suarez. Proceedings of a Symposium,
October 17, 1989, Las Vegas, Nevada. Includes references.
Language: English
Descriptors: Soil chemistry; Equations; Kinetics; Simulation
models; Theory; Transport processes
128 NAL Call. No.: 292.8 J82
Laboratory and numerical investigations of immiscible
multiphase flow in soil. Host-Madsen, J.; Jensen, K.H.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Jul.
Journal of hydrology v. 135 (1/4): p. 13-52; 1992 Jul.
Includes references.
Language: English
Descriptors: Soil pollution; Groundwater pollution; Petroleum;
Flow; Hydraulics; Laboratory tests; Simulation models;
Mathematical models; Quantitative analysis
Abstract: Immiscible multiphase flow in porous media is
investigated by laboratory experiments and numerical
simulations. The hydraulic parameters used in mathematical
models for multiphase flow are determined experimentally, and
the interrelations between the individual parameters are
analysed. The experimental data support the applicability of
analytical closed-form expressions for the constitutive
relations, and a scaling procedure is verified in which the
interfacial tensions are used to derive scaling factors. These
simplifications in the parameter requirements are very
valuable from an engineering point of view. A two-dimensional
plexiglass flume is used for studying the flow of lighter-
than-water, non-aqueous phase liquids (LNAPL) in sandy porous
media. The migration of the LNAPL is observed both in the
unsaturated zone and in the saturated zone at the bottom of
the flume. A dual-gamma attenuation system is used for
measuring the phase saturations of organic fluid, water, and
air simultaneously without disturbing the flow. This permits a
two-dimensional quantitative determination of the LNAPL plume
in contrast to many earlier qualitative studies. A black oil
reservoir model is used to simulate immiscible multiphase
flow. By using the parameter estimation methods presented for
establishing the constitutive relations, the model is applied
to the simulation of the laboratory experiments. The
experimental and numerical results compare reasonably well,
thus supporting the adopted model formulation.
129 NAL Call. No.: 100 M38H (1) no.738
Landscape planning for watershed protection the first step. la
Cour, Niels; Fabos, Julius Gy; Ahern, Jack
Massachusetts Agricultural Experiment Station
Amherst, Mass. : Massachusetts Agricultural Experiment
Station, College of Food and Natural Resources, University of
Massachusetts at Amherst,; 1992. x, 77 p. : ill., maps ; 23
cm. (Research bulletin (Massachusetts Agricultural Experiment
Station) ; no. 738.). Received for publication August 1991.
Winter 1992. Includes bibliographical references (p. 75-77).
Language: English; English
Descriptors: Watershed management; Regional planning;
Geographic information systems
130 NAL Call. No.: 292.8 W295
The Las Cruces Trench site: characterization, experimental
results, and one-dimensional flow predictions.
Wierenga, P.J.; Hills, R.G.; Hudson, D.B.
Washington, D.C. : American Geophysical Union; 1991 Oct.
Water resources research v. 27 (10): p. 2695-2705; 1991 Oct.
Includes references.
Language: English
Descriptors: New Mexico; Soil water; Water flow; Solutes;
Transport processes; Infiltration; Semiarid soils; Soil
variability; Wetting front; Saturated hydraulic conductivity;
Deterministic models; Prediction
Abstract: A comprehensive field trench study was conducted in
a semiarid area of southern New Mexico to provide data to test
deterministic and stochastic models of vadose zone flow and
transport. A 4 m by 9 m area was irrigated with water
containing a tracer using a carefully controlled drip
irrigation system. The area was heavily instrumented with
tensiometers and neutron probe access tubes to monitor water
movement and with suction tubes to monitor solute transport.
Approximately 600 disturbed and 600 core samples of soil were
taken to support deterministic and stochastic characterization
of the soil water hydraulic parameters. The core sample-based
saturated hydraulic conductivities ranged from 1.4 to 6731
cm/d with a mean of 533 cm/d and a standard deviation of 647
cm/d, indicating significant spatial variability. However,
visual observation of the wetting front on the trench wall
shows no indication of preferential flow or water flow through
visible root channels and cracks. The tensiometer readings and
the neutron probe measurements also suggest that the wetting
front moves in a fairly homogeneous fashion despite the
significant spatial variability of the saturated hydraulic
conductivity. In addition to the description of the experiment
and the presentation of the experimental results, predictions
of simple one-dimensional uniform and layered soil
deterministic models for infiltration are presented and
compared to field observations. These models are presented
here to provide a base case against which more sophisticated
deterministic and stochastic models can be compared in the
future. The results indicate that the simple models give
adequate predictions of the overall movement of the wetting
front through the soil during infiltration. However, the
models give poor predictions of point values for water content
due to the spatial variability of the soil. Comparisons
between the one-dimensional infiltration model predictions and
field observations show that the use of t
131 NAL Call. No.: 292.8 J82 A
linear cascade model for predicting transport of dissolved
agrochemicals by surface runoff.
Wallach, R.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1991 Sep.
Journal of hydrology v. 126 (3/4): p. 207-224; 1991 Sep.
Includes references.
Language: English
Descriptors: Agricultural chemicals; Runoff water; Surface
layers; Transport processes; Flow; Mathematical models
Abstract: A cascade-based model is used to predict the
dissolved chemical concentration profile at the effluent of a
field. The source of chemicals is the soil surface layer, from
which the chemicals are transferred to the surface runoff and
transported to the field outlet. The model applies a cascade
of perfectly mixed cells analogous to an equivalent surface
runoff water and soil surface laver. Each cell is made of two
interconnected units, where the upper unit represents the
runoff water and the lower unit represents the soil bulk.
Chemical transfer between the two units is controlled by the
convective mass-transfer process through the laminar boundary
laver of the surface runoff flow. The cells are interconnected
through their upper units by runoff water flow. The lower unit
applies a perfectly mixed reactor analog to an equivalent and
homogeneous soil layer of uniform concentration near the soil
surface. called the effective depth of transfer (EDT). The
expression for the concentration within the EDT is simplified
and agrees well with the soil surface concentration as
determined by an analytical solution of the one-dimensional
diffusion equation for the limiting case of no infiltration.
The number of cells in the cascade is a measure of the extent
of axial mixing in runoff flow where the limiting cases are:
(1) a perfective mixed system represented by one cell, and (2)
a zero-mixing system (plug flow) represented by a cascade made
of an infinite number of cells. The distribution of chemical
concentrations for these two extreme cases and for other flows
with varying degrees of mixing are presented.
132 NAL Call. No.: 292.8 W295
Linear transport models for adsorbing solutes.
Roth, K.; Jury, W.A.
Washington : American Geophysical Union, 1965-; 1993 Apr.
Water resources research v. 29 (4): p. 1195-1203; 1993 Apr.
Includes references.
Language: English
Descriptors: Transport processes; Movement in soil;
Adsorption; Solutes; Linear models
Abstract: A unified linear theory for the transport of
adsorbing solutes through soils is presented and applied to
analyze movement of napropamide through undisturbed soil
columns. The transport characteristics of the soil are
expressed in terms of the travel time distribution of the
mobile phase which is then used to incorporate local
interaction processes. This approach permits the analysis of
all linear transport processes, not only the small subset for
which a differential description is known. From a practical
point of view, it allows the direct use of measured
concentrations or fluxes of conservative solutes to
characterize the mobile phase without first subjecting them to
any model. For complicated flow regimes, this may vastly
improve the identification of models and estimation of their
parameters for the local adsorption processes.
133 NAL Call. No.: TD196.M4B56 1992
Long-term behavior of heavy metals in agricultural soils: a
simple analytical model.
Harmsen, K.
Boca Raton : Lewis Publishers; 1992.
Biogeochemistry of trace metals / edited by Domy C. Adriano.
p. 217-247; 1992. (Advances in trace substances research).
Includes references.
Language: English
Descriptors: Agricultural soils; Heavy metals; Solubility;
Leaching; Uptake
134 NAL Call. No.: TD426.J68
Long-term effects of soil heterogeneity on cadmium behavior in
soil. Boekhold, A.E.; Zee, S.E.A.T.M. van der
Amsterdam : Elsevier; 1991 Jun.
Journal of contaminant hydrology v. 7 (4): p. 371-390; 1991
Jun. Includes references.
Language: English
Descriptors: Soil pollution; Cadmium; Behavior; Sandy soils;
Uptake; Hordeum vulgare; Deterministic models; Soil;
Physicochemical properties; Profiles; Leaching; Heterogeneity;
Equations
135 NAL Call. No.: 292.9 AM34
Low-input agriculture as a ground water protection strategy.
Diebel, P.L.; Taylor, D.B.; Batie, S.S.; Heatwole, C.D.
Bethesda, Md. : American Water Resources Association; 1992
Jul. Water resources bulletin v. 28 (4): p. 755-761; 1992 Jul.
Includes references.
Language: English
Descriptors: Virginia; Groundwater pollution; Water quality;
Farm inputs; Farming systems; Profitability; Economic
analysis; Mathematical models
Abstract: Protection of ground water quality is of
considerable importance to local, state, and federal
governments. This study uses a 15-year mathematical
programming model to evaluate the effectiveness of low-input
agriculture, under alternative policy scenarios, as a strategy
to protect ground water quality in Richmond County, Virginia.
The analysis considers eight policy alternatives: cost-sharing
for green manures, two restrictions on atrazine applications
levels, chemical taxation, a restriction on potential chemical
and nitrogen levels in ground water only and in surface and
ground water, and two types of land retirement programs. The
CREAMS and GLEAMS models were used to estimate nitrate and
chemical leaching from the crop root zone. The economic model
evaluates production practices, policy constraints, and water
quality given a long-term profit maximizing objective. The
results indicate that low-input agriculture alone may not be
an effective groundwater protection strategy. The policy
impacts include partial adoption of low-input practices, land
retirement, and the substitution of chemicals. Only mandatory
land retirement policies reduced all chemical and nutrient
loadings or ground water; however, they did not promote the
use of low-input agricultural practices.
136 NAL Call. No.: 56.8 SO3
Lysimeter study of anion transport during steady flow through
layered coarse-textured soil profiles.
Jacobsen, O.H.; Leij, F.J.; Van Genuchten, M.T.
Baltimore, Md. : Williams & Wilkins; 1992 Sep.
Soil science v. 154 (3): p. 196-205; 1992 Sep. Includes
references.
Language: English
Descriptors: Coarse textured soils; Layered soils; Unsaturated
flow; Soil water movement; Soil variability; Transport
processes; Chlorine; Nitrate; Mathematical models; Soil water
retention
137 NAL Call. No.: TD420.A1P7
Management of water resources and eutrophication in the
Federal District of Brazil.
Somlyody, L.; Altafin, I.
Oxford : Pergamon Press; 1992.
Water science and technology : a journal of the International
Association on Water Pollution Research and Control v. 26
(7/8): p. 1813-1822; 1992. In the series analytic: Water
Quality International '92. Part 4 / edited by M. Suzuki, et
al. Proceedings of the Sixtennth Biennial Conference of the
International Association on Water Pollution Research and
Control, held May 24-30, 1992, Washington, D.C. Includes
references.
Language: English
Descriptors: Brazil; Reservoirs; Eutrophication; Water
purification; Sewage; Waste treatment; Algae; Biomass
production; Water resources; Management; Water quality; Models
138 NAL Call. No.: 56.8 J822
Managing the land: a technology perspective.
Shaw, R.R.
Ankeny, Iowa : Soil and Water Conservation Society of America;
1991 Nov. Journal of soil and water conservation v. 46 (6): p.
406-408; 1991 Nov.
Language: English
Descriptors: Land management; Technology transfer; Remote
sensing; Information systems; Computer software; Usda; Water
management; Soil conservation
139 NAL Call. No.: FUQL628.F6M371 1992
Marine resources geographic information system and fishery
resources final report.
Haddad, Kenneth D.
Florida Marine Research Institute, Florida Office of Coastal
Management St. Petersburg, Fla. : Dept. of Natural Resources,
Division of Marine Resources, Florida Marine Research
Institute,; 1992.
1 v. (unpaged) : ill., maps (some col.) ; 28 cm. January,
1992. Funds for this project were provided by the Department
of Environmental Regulation, Office of Coastal Management...
Includes bibliographical references.
Language: English; English
Descriptors: Information storage and retrieval systems; Marine
resources; Watershed management; Fishery management;
Geographic information systems
140 NAL Call. No.: 56.9 SO3
Mathematical analysis of one-dimensional solute transport in a
layered soil profile.
Leij, F.J.; Dane, J.H.; Van Genuchten, M.T.
Madison, Wis. : The Society; 1991 Jul.
Soil Science Society of America journal v. 55 (4): p. 944-953;
1991 Jul. Includes references.
Language: English
Descriptors: Layered soils; Movement in soil; Leaching;
Contaminants; Solutes; Profiles; Interface; Soil boundaries;
Subsurface barriers; Sand; Clay; Mathematical models;
Qualitative techniques; Errors
Abstract: Solute transport studies involving layered media
are important for investigating how restricting layers affect
rates of solute migration in the soil profile and, more
generally, for examining the influence of soil heterogeneity
on solute transport. Analytical solutions of the one-
dimensional advection-dispersion equation (ADE) were obtained
with the help of Laplace transforms for transport in a two-
layered soil profile. Assuming that the layers are, in effect,
semi-infinite, solutions were obtained for first-type
(constant concentration) and third-type (constant flux)
conditions at both the inlet boundary and the interface of the
two layers. Concentration profiles were also obtained for a
finite first layer via numerical inversion of the Laplace
transform solution, using a third-type condition at the inlet,
and, simultaneously, a first- and third-type condition at the
interface. Volume-averaged or resident-type concentrations
were used in all cases. First-type conditions did not meet our
criterion of mass conservation, whereas third-type conditions
caused discontinuities in the concentration at the interfaces
of layers with differing transport parameters. The
concentration at the interface was found to be continuous, and
no mass-balance error occurred, when first- and third-type
conditions were imposed simultaneously at the interface.
Several example calculations show the effect of soil layering
on solute transport in a one-dimensional soil profile.
141 NAL Call. No.: 292.8 W295 A
mathematical model of hillslope and watershed discharge.
Stagnitti, F.; Parlange, J.Y.; Steenhuis, T.S.; Parlange,
M.B.; Rose, C.W. Washington, D.C. : American Geophysical
Union; 1992 Aug.
Water resources research v. 28 (8): p. 2111-2122; 1992 Aug.
Includes references.
Language: English
Descriptors: Connecticut; Watersheds; Water flow; Soil water;
Slopes; Soil water balance; Soil physical properties; Soil
depth; Runoff; Seepage; Evaporation; Water yield; Water
holding capacity; Saturated hydraulic conductivity; Catchment
hydrology; Mathematical models; Prediction
Abstract: A mathematical water balance model describing major
hydrological processes operating within wet forested
watersheds is proposed. The model is capable of predicting
hillslope and watershed discharge, evapotranspiration demands,
hillslope moisture status, and surface and subsurface flow
rates. It is based on soil physical principles and requires
the following input variables: average hillslope angle and
width, average soil depth, precipitation, average daily
evaporation rates, effective saturated hydraulic conductivity,
soil moisture holding capacity and initial moisture content.
These variables are often easily measured from field studies.
However, in some cases, the absence of field data may require
that some of the variables in the model, e.g., saturated
hydraulic conductivity, be estimated or calibrated from
hillslope hydrograph records. The watershed model is composed
of two submodels: a storage model and a hillslope model. The
storage model describes the dynamic variation in water table
elevation in recharge zones and the hillslope model is used to
predict runoff and seepage through flow from surrounding
hillsides. Application of the model is illustrated on a small
watershed located in North Madison, Connecticut.
142 NAL Call. No.: QH540.N3 A
mathematical systems model of nitrate contamination.
Dkstein, L.; Head, K.L.; Bogardi, I.
Berlin, W. Ger. : Springer-Verlag; 1991.
NATO ASI series : Series G : Ecological sciences v. 30: p.
455-476; 1991. In the series analytic: Nitrate contamination:
Exposure, consequence, and control / edited by I. Bogardi and
R.D. Kuzelka. Proceedings of the NATO Advanced Research
Workshop on Nitrate Contamination: Exposure, Consequences, and
Control, September 9-14, 1990, Lincoln, Nebraska. Includes
references.
Language: English
Descriptors: Nitrate; Nitrate fertilizers; Groundwater
pollution; Drinking water; Contamination; Carcinoma; Risk;
Mathematical models; Epidemiology; Simulation models
143 NAL Call. No.: QH545.A1E58
Matrix decision procedure to assess new pesticides based on
relative groundwater leaching potential and chronic toxicity.
Britt, J.K.; Dwinell, S.E.; McDowell, T.C.
Tarrytown, N.Y. : Pergamon Press; 1992.
Environmental toxicology and chemistry v. 11 (5): p. 721-728;
1992. Includes references.
Language: English
Descriptors: Florida; Pesticides; Public health; Toxicity;
Environment; Environmental impact; Groundwater; Groundwater
pollution; Leaching; Registration; Indexes; Ranking;
Environmental protection; Subtropics; Models
144 NAL Call. No.: TD224.I3P75 1991
McCook Reservoir water quality model numerical model
investigation. Price, Richard E.; Tillman, Dottie
United States, Army, Corps of Engineers, Chicago District,
U.S. Army Engineer Waterways Experiment Station
Vicksburg : Miss. : U.S. Army Engineer Waterways Experiment
Station ; Springfield, Va. : Available from National Technical
Information Service,; 1991.
48 p. : ill. ; 28 cm. (Technical report (U.S. Army Engineer
Waterways Experiment Station) ; HL-91-17.). September 1991.
Cover title. Bibliography: p. 46-48.
Language: English
Descriptors: McCook Reservoir (Ill.); Reservoirs; Water
quality; Flood dams and reservoirs
145 NAL Call. No.: QH84.8.B46
Measured and simulated denitrification activity in a cropped
sandy and loamy soil.
Vinther, F.P.
Berlin : Springer International; 1992.
Biology and fertility of soils v. 14 (1): p. 43-48; 1992.
Includes references.
Language: English
Descriptors: Denmark; Hordeum vulgare; Lolium multiflorum;
Denitrification; Leaching; Losses from soil systems;
Measurement; Nitrogen; Soil temperature; Soil water; Long term
experiments; Loam soils; Sandy soils
146 NAL Call. No.: SB610.2.B74
Measurement and modelling of pesticide residues at Rosemaund
Farm. Williams, R.J.; Brooke, D.N.; Glendinning, P.J.;
Matthiessen, P.; Mills, M.J.; Turnbull, A.
Surrey : BCPC Registered Office; 1991.
Brighton Crop Protection Conference-Weeds v. 2: p. 507-514;
1991. Conference held November 18-21, 1991, Brighton,
England. Includes references.
Language: English
Descriptors: England; Pesticide residues; Water pollution;
Models
147 NAL Call. No.: S541.5.W2R47
Measuring economic benefits of water pollution abatement in an
irrigated river basin.
Willis, D.; May, L.; Gutema, Y.
Pullman, Wash. : The Center; 1992.
Research bulletin XB - Washington State University,
Agricultural Research Center (1019): 24 p.; 1992. Includes
references.
Language: English
Descriptors: Washington; Rivers; Water pollution; Water
quality; Water recreation; Fishing; Irrigation; Pollutants;
Environmental impact; Water purification; Economic impact;
Mathematical models
148 NAL Call. No.: 56.9 SO3
Measuring field variability of disturbed soils for simulation
purposes. Finke, P.A.; Bouma, J.; Stein, A.
Madison, Wis. : The Society; 1992 Jan.
Soil Science Society of America journal v. 56 (1): p. 187-192;
1992 Jan. Includes references.
Language: English
Descriptors: Netherlands; Disturbed soils; Soil variability;
Profiles; Spatial variation; Soil surveys; Thickness;
Determination; Soil structure; Porosity; Soil texture; Soil
organic matter; Soil water content; Soil water retention;
Hydraulic conductivity; Nitrate; Leaching; Soil morphology;
Simulation models
Abstract: Spatial variation of soil profiles disturbed by
leveling was inventoried on a field scale to obtain
representative data for simulation purposes. Depth of
occurrence, thickness, and morphology of functional layers,
which are different pedogenetic horizons with comparable soil
physical properties, were considered to be regionalized
variables. The layers served as carriers of physical
information, such as water-retention and hydraulic-
conductivity characteristics and organic-matter content. An
impression of the variability within each layer was obtained
by six fold sampling. Spatial variability, expressed by
variations in thickness of functional layers, was inventoried
in a two-step soil survey. First, semivariograms were
constructed using data obtained following a nested sampling
scheme supplemented by a nugget estimation procedure.
Variograms were used to evaluate cost/quality ratios at
varying potential grid sampling densities, using the root of
the prediction error variance (RPEV) to compare quality of
interpolations. Based on these evaluations and a sequential
sampling test, a grid mesh of 12 m was chosen. Second, a grid
soil survey and an independent quality test were done, in
which root mean square errors (RMSE) on test points were
compared with RPEV. The RPEV to RMSE ratios varied between 0.7
and 1.1 for the sampled grid mesh, and had comparable values
for other grid meshes. Estimations on test points by an
hypothesized spatial mean, based on 26 measurements by a
sequential sampling method, produced RMSE values not
significantly different from RMSE values from kriging
interpolations. However, sequential sampling required 26
observations whereas kriging required 153, a saving of 93%.
149 NAL Call. No.: 56.8 J823
Measuring the diffusion coefficient of rhizosphere exudates in
soil. I. The diffusion of non-sorbing compounds.
Darrah, P.R.
Oxford : Blackwell Scientific Publications; 1991 Sep.
The Journal of soil science v. 42 (3): p. 413-420; 1991 Sep.
Includes references.
Language: English
Descriptors: Brown earths; Root exudates; Diffusivity;
Measurement; Solutes; Transport processes; Rhizosphere;
Mathematical models; Sorption
Abstract: A quick, convenient and robust method is presented
for measuring the effective diffusion coefficients of non-
sorbing solutes in soil. The method estimates the effective
diffusion coefficient from a measured diffusion profile by
optimizing the solution of a numerical simulation model
describing the experimental system. The method was used to
measure the effective diffusion coefficients of compounds
found in root exudates.
150 NAL Call. No.: 56.8 J823
Measuring the diffusion coefficients or rhizosphere exudates
in soil. II. The diffusion of sorbing compouds.
Darrah, P.R.
Oxford : Blackwell Scientific Publications; 1991 Sep.
The Journal of soil science v. 42 (3): p. 421-434; 1991 Sep.
Includes references.
Language: English
Descriptors: Brown earths; Root exudates; Diffusivity;
Measurement; Transport processes; Rhizosphere; Sorption
isotherms; Mathematical models; Simulation models; Sorption;
Solutes
Abstract: A mathematical model was developed which was
capable of simulating the diffusion of compounds with a
concentration-dependent diffusion coefficient, by virtue of
their sorption on the solid phase of the soil. Methods were
developed which allowed the sorption characteristics and the
effective diffusion coefficient of several organic compounds
to be inferred from their measured diffusion profiles.
151 NAL Call. No.: 56.8 J823 A
method for assessing the goodness of computer simulation of
soil processes. Whitmore, A.P.
Oxford : Blackwell Scientific Publications; 1991 Jun.
The Journal of soil science v. 42 (2): p. 289-299; 1991 Jun.
Includes references.
Language: English
Descriptors: Soil testing; Bromide; Diffusion; Nitrate
nitrogen; Leaching; Movement in soil; Computer simulation;
Simulation models; Assessment; Evaluation; Statistical
analysis; Statistical data; Measurement; Variation;
Experimental design; Replication; Temporal variation;
Mathematics; Errors
Abstract: Any satisfactory computer simulation model of a
soil process must match actual behaviour in the laboratory or
field; a model can be evaluated by how well it does so. This
paper describes a method for assessing models using anion
diffusion and nitrate leaching as examples. The method
partitions the sum of squares of the differences between
measurement and simulation into two components, one calculated
from the differences between the simulation and the mean of
replicate measurements (the 'lack of fit'), and the other
calculated from the variance within each set of replicate
measurements (the 'pure error'). If the former is not
significantly larger than the latter than the data present no
grounds for rejecting the model. Where a model simulates the
change in a process with time the method can also take account
of how experimental error in the initial measurements affects
the goodness of fit of the simulation of subsequent
measurements. The method is particularly valuable where it is
difficult or costly to take many replicate measurements, such
as often happens in soil science or agriculture; nonetheless,
some replicates must be taken.
152 NAL Call. No.: 56.8 SO3 A
method for studying nonequilibrium sorption during transport
of pesticides in soil.
Kookana, R.S.; Gerritse, R.G.; Aylmore, L.A.G.
Baltimore, Md. : Williams & Wilkins; 1992 Nov.
Soil science v. 154 (5): p. 344-349; 1992 Nov. Includes
references.
Language: English
Descriptors: Soil analysis; Linuron; Simazine; Sorption;
Kinetics; Transport processes; Simulation models; Saturated
conditions; Movement in soil
153 NAL Call. No.: QH540.J6
Microlysimeter soil columns for evaluating pesticide movement
through the root zone.
Fermanich, K.J.; Daniel, T.C.; Lowery, B.
Madison, Wis. : American Society of Agronomy; 1991 Jan.
Journal of environmental quality v. 20 (1): p. 189-195; 1991
Jan. Includes references.
Language: English
Descriptors: Pesticides; Leaching; Lysimetry; Measurement;
Movement in soil; Simulation models; Soil temperature; Soil
water; Water balance
Abstract: Field approaches to studying pesticide movement are
subject to numerous variables of the environment, many of
which are difficult and expensive to monitor. This study
describes the design, construction, operation, and performance
of intact microlysimeter soil (Plainfield loamy sand-mixed,
mesic, Typic Udipsamment) columns used to examine the mobility
of two insecticides through soil from two tillage plots
(conventional-moldboard plow and no-till tillage). Field
leaching conditions were approximated by simulating a moisture
and temperature regime characteristic of a natural soil
profile. Measured daily and seasonal temperature fluctuated
according to a pattern characteristic of a field soil.
Evapotranspiration (ET) from the soil columns was 61% of the
total water applied and was nearly equal to the ET measured
(63%) from field lysimeters of this soil planted to corn (Zea
mays L.). Variation in cumulative drainage was small, total
drainage from all columns was within a range of 3.9 cm. There
was no significant difference in the transport of bromide
(conservative tracer) through columns from the two tillage
plots. Bromide leachate loss was 62 and 63% of the amount
applied for conventional-moldboard plow and no-till columns,
respectively. Intact soil columns established in a
microlysimeter fashion provided a means to compare the
movement of agricultural chemicals under controlled conditions
in the greenhouse that approximate conditions/processes in the
field.
154 NAL Call. No.: 292.8 W295
Microtargeting the acquistion of cropping rights to reduce
nonpoint source water pollution.
Kozloff, K.; Taff, S.J.; Wang, Y.
Washington, D.C. : American Geophysical Union; 1992 Mar.
Water resources research v. 28 (3): p. 623-628; 1992 Mar.
Includes references.
Language: English
Descriptors: Minnesota; Agricultural land; Land use; Land
management; Watersheds; Water pollution; Water quality;
Erosion; Sediment yield; Simulation models; Cost effectiveness
analysis
Abstract: Targeting cropland retirement programs to reduce
agricultural nonpoint source pollution is accomplished by
employing disaggregated information about physical and
economic factors that influence the benefits and costs of
adopting specific erosion control practices on specific land
parcels. The agricultural nonpoint source (AGNPS) model is
used in a Minnesota watershed to simulate the relative
effectiveness of alternative targeting schemes with respect to
budget outlays for annual payments to landowners, reduction in
downstream sediment yield and nutrient loss, and reduction in
on-site erosion. Cost-effectiveness increased with information
on economic factors (the opportunity cost of retiring a parcel
of land) as well as on physical factors (contribution of a
parcel to downstream sediment yield). The marginal cost-
effectiveness of all schemes decreased as the enrolled
proportion of watershed land increased.
155 NAL Call. No.: TD403.G7
Model development and simulation of bioremediation in soil
beds with aggregates.
Dhawan, S.; Erickson, L.E.; Fan, L.T.
Dublin, Ohio : Ground Water Pub. Co; 1993 Mar.
Ground water v. 31 (2): p. 271-284; 1993 Mar. Includes
references.
Language: English
Descriptors: Soil pollution; Groundwater pollution; Organic
compounds; Biodegradation; Simulation models; Soil; Aggregates
Abstract: One method of remediating contaminated soil and
ground water is through management of the subsurface
environment so that indigenous microorganisms can biodegrade
organic contaminants. Modeling and simulation offer promising
means of assessing the migration and attenuation of such
contaminants being treated in situ in the subsurface. In this
paper, a macropore flow model has been developed to account
for bioremediation in the interstitial spaces among soil
aggregates. This model has been combined with another
bioremediation model which accounts for diffusion and
biodegradation in the micropores and soil particles in the
aggregates. The combined model comprises a system of six
coupled equations, of which three are nonlinear ordinary
differential equations and three are nonlinear partial
differential equations. Dimensional analysis of these
equations has yielded useful dimensionless parameters for
evaluating the relative significance of each mechanism in
remediation. Numerical experiments have been conducted to
evaluate the effects of initial contaminant concentration,
aggregate size, and soil-water partition factor. The total
time of remediation has been found to depend on the rate at
which contaminants are consumed within the large aggregates
which, in turn, depends on the biodegradation kinetics and the
rates of diffusion of substrate and oxygen in the aggregates.
For soil with aggregates whose radius is 1 cm or larger, the
results of simulation indicate that the remediation time for
the aggregates is significantly longer compared to the
corresponding result for homogeneous soil. For contaminants
with large partition coefficients, the estimated time for
remediation achieved through microbial oxidation in situ is
much shorter than that achieved through purely diffusional
transport of the contaminants out of the soil bed.
156 NAL Call. No.: TD419.R47 A
model for evaluating the impacts of land application of
organic waste on runoff water quality.
Deizman, M.M.; Mostaghimi, S.
Alexandria, Va. : The Federation; 1991 Jan.
Research journal of the Water Pollution Control Federation v.
63 (1): p. 17-27; 1991 Jan. Includes references.
Language: English
Descriptors: Organic wastes; Application to land; Organic
fertilizers; Runoff water; Water pollution; Soil pollution;
Simulation models; Agricultural land; Nitrogen;
Transformation; Losses
157 NAL Call. No.: 292.8 J82 A
model for oxygen transport and consumption in the unsaturated
zone. Refsgaard, J.C.; Christensen, T.H.; Ammentorp, H.C.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1991 Dec.
Journal of hydrology v. 129 (1/4): p. 349-369; 1991 Dec.
Includes references.
Language: English
Descriptors: Soil water; Soil air; Oxygen transport; Oxygen
consumption; Solutes; Transport processes; Unsaturated flow;
Diffusion; Diffusivity; Soil water content; Crumbs; Size;
Denitrification; Mathematical models
Abstract: An oxygen transport and consumption model has been
developed as a submodel to a general numerical model for
solute transport in the unsaturated zone. The model comprises
diffusive and convective transport of oxygen in soil air,
convective transport and oxygen consumption in free water, and
diffusive transport and a constant-rate oxygen consumption in
the water-saturated soil crumbs. The model also estimates the
anaerobic fraction of the water-saturated crumbs where no
oxygen consumption takes place. The model dynamics and
applicability are illustrated using the examples of the
operation of a waste water infiltration plant and of anaerobic
zones in the soil of importance for modelling denitrification.
158 NAL Call. No.: 56.9 SO3
Model of boron movement in soils.
Shani, U.; Dudley, L.M.; Hanks, R.J.
Madison, Wis. : The Society; 1992 Sep.
Soil Science Society of America journal v. 56 (5): p.
1365-1370; 1992 Sep. Includes references.
Language: English
Descriptors: Calcareous soils; Boron; Movement in soil;
Transport processes; Simulation models; Mathematical models
Abstract: A model to predict B transport in calcareous soils
is presented. The model considers one-dimensional, non-steady-
state soil water flow, convective-dispersive solute transport
of both noninteracting salt (i.e., Cl) and B. The model was
designed to simulate field situations including infiltration,
evaporation, transpiration, drainage, and water extraction by
plant roots. Predictions were compared with field B profiles
and column leaching studies. The model accurately simulated
Bleaching from columns of B-contaminated soils under saturated
and steady-state water flow conditions. Model simulations,
Udder conditions of transient water flow and transient B
concentrations in a column study, were in reasonable agreement
with the measured values. Model predictions were also compared
with evolving soil soluble-B profiles determined in a field
study (5-7 yr) with repeated irrigation with saline, B-
containing waters. Computed results of the B accumulation in
the upper portion of the soil profile, and of the B front,
were in good agreement with measured data.
159 NAL Call. No.: TD172.J6
Model simulation and regional pollution reduction strategies.
Shirmohammadi, A.; Shoemaker, L.L.; Magette, W.L.
New York, N.Y. : Marcel Dekker; 1992 Dec.
Journal of environmental science and health : Part A :
Environmental science and engineering v. 27 (8): p. 2319-2336;
1992 Dec. Includes references.
Language: English
Descriptors: Maryland; Soil pollution; Groundwater pollution;
Nitrogen; Losses; Erosion control; Coastal plains; Mountain
areas; Plains; Tillage; Practice; Simulation models;
Cultivation; Cropping systems; Fertilizers; Application
methods
160 NAL Call. No.: 292.8 W295
Modeling base flow soil water residence times from deuterium
concentrations. Stewart, M.K.; McDonnell, J.J.
Washington, D.C. : American Geophysical Union; 1991 Oct.
Water resources research v. 27 (10): p. 2681-2693; 1991 Oct.
Includes references.
Language: English
Descriptors: New Zealand; Soil water; Transport processes;
Rain; Water flow; Stream flow; Watersheds; Deuterium;
Measurement; Mathematical models
Abstract: Three approaches to determining mean soil water
residence times in a steep headwater catchment were
investigated. The deuterium concentrations of soil water
collected from 11 suction cup samplers at the Maimai M8
catchment were determined weekly for 14 weeks and the results
compared with those of rainfall in the same period. Deuterium
variations in the suction samples were considerably delayed
and diminished compared with the rainfall, indicating
significant storage times and mixing with soil water. Soil
matrix water at shallow levels (approximately 200 mm depth) in
unsaturated soils was relatively responsive to fresh input,
but deeper water and water near the stream subject to
occasional water table rises showed much less variation.
Steady state and non-steady state exponential models gave
similar mean residence times, ranging from 12 to more than 100
days for different locations. Three groups of soil water
response were defined, comprising shallow, medium and deep
(near-stream) soil locations based on the mean residence
times. The nonsteady models revealed considerable week-to-week
and longer variations in mean residence time for shallow soil
(SL4), but indicated that steady state models could adequately
represent the system in the overall period investigated. In
the third approach, model types and parameters that gave the
best fits to the soil water deuterium concentrations were
determined. Exponential and especially dispersion models were
the most satisfactory. Weighting the input (rainfall delta D)
partially or fully with the amount of rainfall gave much worse
fits than with the unweighted input, showing that much of the
rainfall bypasses the soil matrix. The best fitting dispersion
model (designated DM2) yielded the most accurate mean
residence times: 13 days for shallow soil (SL4), 42 days for
soil at 400 mm depth (SL5), both at midslope locations, and 63
days for soil at 800 mm depth near the stream (SL2). Capillary
flow was important for the unsaturated s
161 NAL Call. No.: KyUThesis 1991 Storm
Modeling dynamic rill networks from random surfaces on
moderate slopes. Storm, Daniel E.
1991; 1991.
2 v. : ill. ; 28 cm. Includes vita and abstract. Includes
bibliographic refernces (l. 499-508).
Language: English
Descriptors: Soil erosion; Drainage; Probabilities
162 NAL Call. No.: 292.8 W295
Modeling infiltration for multistorm runoff events.
Smith, R.E.; Corradini, C.; Melone, F.
Washington, D.C. : American Geophysical Union; 1993 Jan.
Water resources research v. 29 (1): p. 133-144; 1993 Jan.
Includes references.
Language: English
Descriptors: Infiltration; Mathematical models; Soil water
movement; Redistribution; Runoff; Soil water content; Rain;
Storms; Simulation
Abstract: We present a relatively simple
analytical/conceptual model for rainfall infiltration during
complex storms. It is an approximate but physically based
model which can treat intervals of either no rain, low rain,
or evaporation. The infiltration model is based on the very
general three-parameter analytic model of Parlange et al.
(1982), extended to treat soils with very high initial water
content. The redistribution model is based on profile
extension with shape similarity. A wide range of soil types
can be simulated. The model is tested by comparison with
numerical solutions of Richards's equation carried out for a
variety of events upon four selected soils. The model
simulates the solution to Richards's equation quite
accurately, provided basic soil retention relations are
parametrically represented. It simulates redistribution
particularly well for redistribution intervals up to 20 hours.
The model usefulness in comparison with the common and simple
approach which disregards soil water redistribution is also
shown.
163 NAL Call. No.: 292.8 W295
Modeling long-term solute transport in drained unsaturated
zones. Kandil, H.; Miller, C.T.; Skaggs, R.W.
Washington, D.C. : American Geophysical Union; 1992 Oct.
Water resources research v. 28 (10): p. 2799-2809; 1992 Oct.
Includes references.
Language: English
Descriptors: Unsaturated flow; Transport processes; Solutes;
Drained conditions; Soil water balance; Water table; Water
quality; Prediction; Simulation; Mathematical models;
Algorithms
Abstract: Long-term assessment of solute transport in the
unsaturated zone is an important consideration for irrigation
management, pesticide management, and subsurface contaminant
restoration analysis and design. Mathematical models are often
used to perform such analyses. Modeling fluid flow and solute
transport in the unsaturated zone typically requires solution
of the nonlinear Richards equation and an advective-dispersive
equation for contaminant transport as a function of time. Such
solutions are possible but computationally expensive. A
simplified water balance approach to solve fluid flow in
shallow, drained unsaturated zones has been developed and
refined over the last 15 years. The objectives of this study
were to use results from a water balance model to obtain
solutions for solute transport in drained, shallow water table
soils, and to compare the results with solutions based upon
Richards' equation. Transient soil water flux rates computed
with a water balance model were used as input to a Petrov-
Galerkin advective-dispersive transport model to simulate
solute transport in unsaturated soils. The transport model was
checked for consistency by comparison with an analytical
solution. Sample simulations showed good agreement between a
Richards' equation-based transport model and a water balance-
based transport model. Simulations were performed to show
predicted trends in water quality over 1-year periods.
164 NAL Call. No.: 292.8 W295
Modeling of carbon dioxide transport and production in soil.
1. Model development.
Simunek, J.; Suarez, D.L.
Washington, D.C. : American Geophysical Union; 1993 Feb.
Water resources research v. 29 (2): p. 487-497; 1993 Feb.
Includes references.
Language: English
Descriptors: Carbon dioxide; Production; Transport processes;
Spatial distribution; Water flow; Heat flow; Respiration; Soil
biology; Soil chemistry; Prediction; Simulation models;
Mathematical models
Abstract: Knowledge of the CO2 concentration in the
unsaturated zone is essential for prediction of solution
chemistry in the vadose zone and groundwater recharge as well
as for quantifying carbon source/sink terms as part of the
global CO2 mass balance. In this paper we present a predictive
simulation model, SOILCO2, based on process-oriented
relationships. The model includes one-dimensional water flow
and multiphase transport of CO2 utilizing the Richards and the
convection-dispersion equations, respectively, as well as heat
flow and a CO2 production model. The transport of CO2 in the
unsaturated zone can occur in both the liquid and gas phases.
The gas transport equation accounts for production of CO2 and
uptake of CO2 by plant roots associated with root water
uptake. The CO2 production model considers both microbial and
root respiration which is dependent on water content,
temperature, growth, salinity and plant and soil
characteristics. Heat flow is included, since some gas
transport parameters, partitioning coefficients and production
parameters are strongly temperature dependent. The resulting
set of partial differential equations is solved numerically
using the finite element and finite difference methods.
165 NAL Call. No.: 292.8 W295
Modeling of carbon dioxide transport and production in soil.
2. Parameter selection, sensitivity analysis, and comparison
of model predictions to field data.
Suarez, D.L.; Simunek, J.
Washington, D.C. : American Geophysical Union; 1993 Feb.
Water resources research v. 29 (2): p. 499-513; 1993 Feb.
Includes references.
Language: English
Descriptors: California; Missouri; Carbon dioxide; Production;
Spatial distribution; Transport processes; Mathematical
models; Simulation models; Prediction; Steady flow; Transient
flow; Water flow; Heat flow; Triticum aestivum; Zea mays;
Glycine max; Environmental factors
Abstract: In paper 1 of this two-paper series (Simunek and
Suarez, this issue) we presented a description of the
numerical model, SOILCO2, for CO2 transport and production in
the unsaturated zone. In paper 2 the model sensitivity to
various parameters is evaluated by both steady state and
transient simulations, with a range in the parameter values
typically found under field conditions. We also select
parameter values for optimal plant and microbial CO2
production and production dependence on temperature, water
content, osmotic potential and gas composition for plant and
microbial respiration, all based on literature review. The
predictive capabilities of the SOILCO2 model are evaluated by
comparing model simulations to published field data from
Missouri for three different crops and two growing seasons
under transient conditions as well as a data set collected in
Riverside, California, under relatively constant water content
at depth. The model provided good prediction of the CO2 flux
to the atmosphere as well as the concentrations in the root
zone for all data sets.
166 NAL Call. No.: TD1.E2 no.91/039
Modeling of nonpoint source water quality in urban and non-
urban areas. Donigian, Anthony S.; Huber, Wayne C.
Environmental Research Laboratory (Athens, Ga.)
Athens, Ga. : Environmental Research Laboratory, Office of
Research and Development, U.S. Environmental Protection
Agency,; 1991. vi, 72 p. : ill. (EPA/600/3 ; 91/039). June
1991. Includes bibliographical references.
Language: English
Descriptors: Water
167 NAL Call. No.: 290.9 AM32T
Modeling pollutant transport in runoff and sediment.
Ashraf, M.S.; Borah, D.K.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 Nov. Transactions of the ASAE v. 35 (6): p.
1789-1797; 1992 Nov. Includes references.
Language: English
Descriptors: Agricultural chemicals; Cyanazine; Nitrates;
Phosphates; Pollutants; Rain; Runoff; Sediment; Simulation
models
Abstract: A dynamic model was developed to simulate mixing of
rainwater with soils containing agricultural nutrients and
pesticides, entrainment of these pollutants to runoff, and
their transport in runoff and sediment within a watershed and
during a single storm event. The model is an advancement to
the existing models in simulating chemical transport during
individual storms. It routes infiltrating rainwater and
solutes through the soil profile using concepts of complete
mixing and piston displacement. When runoff begins, chemical
exchange between runoff and a mixing soil layer of the soil
profile, containing the chemicals in dissolved and adsorbed
forms, are simulated using the concept of non-uniform mixing
with respect to the soil layer depths. Entrained chemicals in
runoff are routed along slope lengths in dissolved and
adsorbed forms based on mass conservation. The basic model
concepts and algorithms on chemical mixing and entrainment
were tested for time varying concentrations of nitrate,
phosphate, and cyanazine in runoff using a suitable laboratory
data set found in the literature. A total of 15 model runs, 5
for each pollutant, were made. Predicted concentrations were
compared with the respective observed data. The comparisons
showed that the concepts and the algorithms were valid and
promising.
168 NAL Call. No.: QH540.J6
Modeling selenium transport in steady-state, unsaturated soil
columns. Alemi, M.H.; Goldhamer, D.A.; Nielsen, D.R.
Madison, Wis. : American Society of Agronomy; 1991 Jan.
Journal of environmental quality v. 20 (1): p. 89-95; 1991
Jan. Includes references.
Language: English
Descriptors: Selenium; Soil air; Soil chemistry; Soil flora;
Soil sterilization; Transport processes; Adsorption; Leaching;
Methodology; Microbial activities; Simulation models
Abstract: This study was conducted to characterize batch
adsorption of selenate SeO4(2-), selenite (SeO4(2-), and
selenomethionine (Se-CH2CH2CHNH2COOH)2 and transformations of
Se in the presence of microbial activity in Panoche loam
(fine-loamy, mixed, calcareous, thermic Typic Torriorthents).
The effects of sterilization, enhanced microbial activity, and
aerobic vs. anaerobic conditions on the transport of pulse-fed
Se in soil columns were also investigated. Selenate was
rapidly leached in the soil columns compared with
selenomethionine and selenite both of which invaded the
columns to only a limited extent. Adsorption was highest for
selenite and least for selenate. Selenate was transformed to
reduced and less mobile forms when soil was C-enriched,
particularly with smaller water fluxes and under anaerobic
conditions. Systems of partial differential equations (PDEs)
involving equilibrium adsorption of Se are set up to simulate
transport of selenate, selenite, and selenomethionine under
sterilized conditions. The transport model is solved by an
iterative procedure using a finite difference scheme.
Experimentally determined adsorption parameters of selenite
and selenomethionine did not produce a satisfactory fit when
used in simulation of these Se species in column studies. The
Se transport model adequately simulated Se concentrations in
soil solution under sterilized conditions when the adsorption
coefficients derived from batch experiments were adjusted. No
transport modeling was considered for nonsterilized
conditions.
169 NAL Call. No.: SB191.R5I59
Modeling soil processes with N dynamics as an example.
Kirk, G.J.D.; Rachhpal-Singh
Manila : The Institute; 1991 Nov.
IRRI research paper series - International Rice Research
Institute (151): p. 39-42; 1991 Nov. In the series analytic:
Systems simulation at IRRI / edited by F.W.T. Penning de
Vries, M.J. Kropff, P.S. Teng, and G.J.D. Kirk. Includes
references.
Language: English
Descriptors: Urea fertilizers; Prediction; Transport
processes; Volatilization; Simulation models; Computer
simulation; Losses from soil systems; Nitrogen; Rhizosphere
170 NAL Call. No.: 292.8 W295
Modeling solute transport influenced by multiprocess
nonequilibrium and transformation reactions.
Brusseau, M.L.; Jessup, R.E.; Rao, P.S.C.
Washington, D.C. : American Geophysical Union; 1992 Jan.
Water resources research v. 28 (1): p. 175-182; 1992 Jan.
Includes references.
Language: English
Descriptors: Contaminants; Solutes; Transport processes;
Sorption; Transformation; Degradation; Prediction; Simulation;
Mathematical models
Abstract: We present an advective-dispersive solute transport
model that explicitly accounts for multiple sources of
nonequilibrium and transformation reactions during steady
state flow in porous media. The multiprocess nonequilibrium
with transformation (MPNET) model is formulated for cases
where nonequilibrium, caused by a combination of transport-
related and sorption-related processes, and abiotic/biotic
transformations can be described as first-order processes. The
impact of the coupling of nonequilibrium and transformation
reactions on solute transport is examined using selected
illustrative examples. The performance of the model is
evaluated by comparing predictions obtained with the model,
where values for all model parameters are obtained
independently, to a data set obtained from the literature. The
prediction obtained with the MPNET model matched the data very
well, much better than did the predictions obtained with the
MPNET model assuming no degradation and with a model that does
not account for rate-limited sorption.
171 NAL Call. No.: QH540.J6
Modeling the influence of sorption and transformation on
pesticide leaching and persistence.
Boesten, J.J.T.I.; Linden, A.M.A. van der
Madison, Wis. : American Society of Agronomy; 1991 Apr.
Journal of environmental quality v. 20 (2): p. 425-435; 1991
Apr. Includes references.
Language: English
Descriptors: Diuron; Aldicarb; Leaching; Persistence; Soil
morphological features; Sandy soils; Mathematical models;
Application date; Spring; Autumn; Continuous cropping; Zea
mays; Water uptake; Water flow; Soil temperature;
Precipitation; Evapotranspiration
Abstract: Pesticide leaching to ground water at 1 m depth and
pesticide persistence in the plow layer were calculated with a
mathematical model for a sandy soil continuously cropped with
maize (Zea mays L.) and exposed to weather conditions in a
temperate climate. The pesticide was applied in spring. In the
model water flow was described by Darcy's law and water uptake
by the crop was included. Daily averages of meteorological
conditions (rainfall, evapotranspiration, soil temperature)
were used as input. The model assumes first-order
transformation, equilibrium sorption (Freundlich equation),
and passive plant uptake. Pesticide leaching and persistence
were calculated as a function of pesticide sorption
(characterized by the organic-matter/water distribution
coefficient, Kom) and of transformation rate. It was found
that pesticide leaching is very sensitive to both Kom and the
transformation rate: changing Kom or the transformation rate
by a factor of 2 changes the fraction of the dose leached
typically by about a factor of 10. Pesticide persistence in
the plow layer was found to be sensitive to Kom at low
transformation rates and sensitive to the transformation rate
at high Kom values. Additional calculations showed that autumn
application results in much higher leaching of nonsorbing
pesticides with short half-lives than spring application
(difference of two orders of magnitude).
172 NAL Call. No.: 292.8 W295
Modeling the nonequilibrium transport of linearly interacting
solutes in porous media: a review.
Sardin, M.; Schweich, D.; Leij, F.J.; Van Genuchten, M.T.
Washington, D.C. : American Geophysical Union; 1991 Sep.
Water resources research v. 27 (9): p. 2287-2307; 1991 Sep.
Includes references.
Language: English
Descriptors: Transport processes; Solutes; Aggregates;
Porosity; Soil pore system; Time; Dynamics; Kinetics;
Mathematical models
Abstract: The transport of linearly interacting solutes in
porous media is investigated with the help of residence time
distributions, transfer functions, methods of system dynamics,
and time-moment analyses. The classical one-dimensional
convection-dispersion equation is extended to two-region
(mobile-immobile water) transport by including diffusional
mass transfer limitations characteristic of aggregated soils.
The two-region model is further revised by incorporating the
effects of multiple retention sites (in parallel or in
series), multiple porosity levels, and arbitrary but steady
flow fields. It is shown that different physical situations
can be represented by a relatively small number of transfer
functions containing only two types of parameters:
distribution coefficients to account for equilibrium
properties and characteristic times reflecting kinetic
processes. Relevant kinetic processes include convective
transport, hydrodynamic dispersion, adsorption-desorption, and
physical or chemical mass transfer limitations. In most
situations, theoretical breakthrough curves are found to be
relatively insensitive to the mathematical structure of the
transfer function, irrespective of the physical interpretation
of the distribution coefficients and the characteristic times
in the model. This means that alternative physical and
chemical interpretations of model parameters can lead to
nearly identical breakthrough curves. Certain transfer time
distributions can lead to quite unusual shapes in the
breakthrough curves; these curves strongly depend on the
characteristic times and a few operational variables. Results
of this study show that the transfer time distribution is an
extremely useful tool for explaining some unexpected
experimental results in the solute transport literature.
173 NAL Call. No.: 56.9 SO3
Modeling the transport and retention of cadmium in soils:
multireaction and muticomponent approaches.
Selim, H.M.; Buchter, B.; Hinz, C.; Ma, L.
Madison, Wis. : The Society; 1992 Jul.
Soil Science Society of America journal v. 56 (4): p.
1004-1015; 1992 Jul. Includes references.
Language: English
Descriptors: Soil types (genetic); Cadmium; Transport
processes; Heavy metals; Retention; Kinetics; Mathematical
models; Simulation models; Ion exchange; Sorption
Abstract: A major challenge in modeling the mobility or
solutes in soils is to take into account the time-dependent
retention of reactive solutes in a transport model that can be
evaluated by independent experiments. The kinetics of
retention and transport or Cd in two soils were investigated
in this study. Time-dependent batch experiments were carried
out to describe the extent of Cd sorption by two soils.
Miscible-displacement experiments were conducted to quantify
Cd transport in soil columns that received single and multiple
Cd pulses. A multi-reaction convective-dispersive transport
model inadequately predicted effluent concentrations for both
soils when independently measured parameters of retention-
release rate coefficients were obtained from batch data sets.
We developed a multicomponent approach that accounts for
reversible and irreversible Cd retention during transport in
soils. Retention mechanisms considered include instantaneous
equilibrium ion exchange and a specific sorption process that
was based on a second-order (Langmuir) kinetic reaction. The
multicomponent model adequately predicted the observed
breakthrough results. The use of kinetic ion exchange and
specific sorption for irreversible retention provided improved
overall predictions of the results. Parameter values used for
the rates of specific sorption (kf) and that for kinetic ion
exchange (alpha) which provided improved predictions for
single-pulse applications, were similar to those used for
multiple-pulse applications. This finding was consistent for
both soils and was considered to add credence to our
multicomponent model.
174 NAL Call. No.: 30 AD9
Modeling the transport and retention of inorganics in soils.
Selim, H.M.
San Diego, Calif. : Academic Press; 1992.
Advances in agronomy v. 47: p. 331-384; 1992. Literature
review. Includes references.
Language: English
Descriptors: Soil chemistry; Solutes; Transport processes;
Leaching; Movement in soil; Mathematical models; Literature
reviews
175 NAL Call. No.: QH545.A1E58
Modelling pesticide movement in forested watersheds: use of
PRZM for evaluating pesticide options in loblolly pine stand
management. Dowd, J.F.; Bush, P.B.; Neary, D.G.; Taylor, J.W.;
Berisford, Y.C. Tarrytown, N.Y. : Pergamon Press; 1993 Mar.
Environmental toxicology and chemistry v. 12 (3): p. 429-439;
1993 Mar. Paper presented at the "Symposium on Pesticides in
Forest Management, 11th Annual Meeting of the Society of
Environmental Toxicology and Chemistry," November 11-15, 1990,
Arlington, Virginia. Includes references.
Language: English
Descriptors: Georgia; Pesticides; Watersheds; Forests; Pinus
taeda; Leaching; Profiles; Weather; Climatic factors; Soil
water movement; Forest management; Simulation models;
Prediction
176 NAL Call. No.: 292.8 J82
Modelling surface runoff contamination by soil chemicals under
transient water infiltration.
Wallach, R.; Shabtai, R.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Mar.
Journal of hydrology v. 132 (1/4): p. 263-281; 1992 Mar.
Includes references.
Language: English
Descriptors: Agricultural chemicals; Contamination; Soil
water; Runoff; Overland flow; Rain; Solutes; Transport
processes; Infiltration; Sloping land; Relationships;
Prediction; Mathematical models
Abstract: A model was developed to predict the potential
contamination of overland flow by chemicals removed from soil
water by rainfall on sloping soil. The model accounts for
transient water infiltration, overland flow and convective-
dispersive solute transport in the soil. Solutes are assumed
to be subjected to linear equilibrium sorption onto the soil's
solid phase. Numerical simulations indicated that the value of
the coefficient for soil chemical transfer to surface runoff
does not affect the soil surface concentration when soil is
initially dry, but is linearly related to the dissolved
chemical flux to overland flow. This enables an approximate
solution to the convective-dispersive equation for determining
soil surface concentration, independent of its determination
from rainfall-runoff relationships. Simulated dissolved
chemical concentrations at the soil surface and in surface
runoff were determined for different antecedent soil moistures
and rainfall intensities. These concentrations were found to
be lower when antecedent moisture was low, because ponding
time for drier soils is longer and during this period soil
solutes are therefore displaced downward by greater volumes of
infiltrating water. For a specified initial soilwater content,
higher rainfall rates cause higher dissolved chemical
concentrations at the soil surface and in runoff water. The
hydrological parameters (e.g. soil-surface slope, length and
roughness) affecting the residence time of surface water on
the field, greatly affect runoff concentration for a short
time after the initiation of overland flow. The runoff
concentration for longer periods is mainly affected by soil
surface concentration, which is in turn controlled by the
dispersion of the chemicals in the soil. The distribution
coefficient between the liquid and solid phases of the soil
controls the release of adsorbed chemicals to the soil
solution and therefore affects the runoff concentration.
177 NAL Call. No.: 56.8 J823
Modelling water and solute transport in macroporous soil. I.
Model description and sensitivity analysis.
Jarvis, N.J.; Jansson, P.E.; Dik, P.E.; Messing, I.
Oxford : Blackwell Scientific Publications; 1991 Mar.
The Journal of soil science v. 42 (1): p. 59-70; 1991 Mar.
Includes references.
Language: English
Descriptors: Soil physics; Macropore flow; Solutes;
Macropores; Transport processes; Mathematical models;
Diffusion models; Equations
Abstract: A detailed mechanistic model of water movement and
transport of non-reactive solute in a macroporous soil is
described. One important feature of the model is that it may
be run in either one or two flow domains using the same values
for the hydraulic properties characterizing the soil. Water
and solute movement in the micropores is calculated with the
Richards and convection-dispersion equations and, in two
domains, this is coupled to fluxes of water and solute in the
macropores by empirical interaction terms. These interaction
terms are redundant in the one-domain model, which simply
reduces to the non-steady state convection-dispersion
equation. A sensitivity analysis is presented showing how it
is possible to identify conditions under which a macropore
flow domain may need to be considered. In part II (Jarvis et
al., 1991), the model is evaluated under field conditions in
chloride breakthrough experiments in soil monolith lysimeters.
178 NAL Call. No.: 56.8 J823
Modelling water and solute transport in macroporous soil. II.
Chloride breakthrough under non-steady flow.
Jarvis, N.J.; Bergstrom, L.; Dik, P.E.
Oxford : Blackwell Scientific Publications; 1991 Mar.
The Journal of soil science v. 42 (1): p. 71-81; 1991 Mar.
Includes references.
Language: English
Descriptors: Soil physics; Macropore flow; Solutes; Chlorides;
Leaching; Prediction; Topsoil; Hydraulic conductivity;
Porosity; Clay soils; Mathematical models; Diffusion models
Abstract: A model of water and solute transport in
macroporous soils (Jarvis et al., 1991) has been evaluated in
column breakthrough experiments under field conditions.
Hydraulic properties were first measured in replicate soil
monolith lysimeters sampled from grass ley and continuous
barley treatments in a clay soil. A pulse input of 0.05 M KCl
was then supplied by drip irrigation and measurements made of
the water discharge and chloride leaching resulting from the
natural rainfall over a 1-month period. The results showed
that the macropores constituted the dominant flow pathway
(accounting for 80% of the total water outflow) and that
diffusive exchange of chloride between the two flow domains
was the main factor causing variability in leaching. Larger
hydraulic conductivities and macroporosities in the lower
topsoil and at plough depth in the grass ley monoliths were
taken as evidence of structural amelioration. Less of the
applied chloride was leached in the grass monoliths than in
the barley (means of 20% and 31% respectively). This was
mainly due to a smaller effective aggregate size and thus a
more efficient diffusion-controlled retention.
179 NAL Call. No.: 290.9 AM32T
Modification of EPIC to incorporate drainage systems.
Sabbagh, G.J.; Bengtson, R.L.; Fouss, J.L.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 Mar. Transactions of the ASAE v. 34 (2): p.
467-472; 1991 Mar. Includes references.
Language: English
Descriptors: Louisiana; Drainage; Erosion; Evapotranspiration;
Runoff; Simulation models; Water table; Watersheds; Zea mays;
Crop production
Abstract: EPIC-WT is a modified verison of the Erosion
Productivity Impact Calculator (EPIC). It is capable of
determining the relationship between soil erosion and soil
productivity, simulating the daily watertable fluctuations,
and predicting the effect of subsurface drainage systems on
the water budget components for shallow watertable soils.
Validation of the performance of EPIC-WT in simulating surface
and subsurface drained flows, daily watertable fluctuations,
sediment loss, and crop yield was conducted over seven years
(1981-1987) on a clay loam soil near Baton Rouge, LA.
Satisfactory results were obtained.
180 NAL Call. No.: 290.9 AM32T
Modification of Epic to simulate pesticide activities: EPIC-
PST. Sabbagh, G.J.; Geleta, S.; Elliott, R.L.; Williams, J.R.;
Griggs, R.H. St. Joseph, Mich. : American Society of
Agricultural Engineers; 1991 Jul. Transactions of the ASAE v.
34 (4): p. 1683-1692; 1991 Jul. Includes references.
Language: English
Descriptors: Georgia; Louisiana; Atrazine; Metolachlor;
Groundwater; Leaching; Mathematical models; Runoff; Water
pollution
Abstract: The need for a mathematical model capable of
simulating simultaneously the effects of different
agricultural management practices on crop yield, and chemical
(nutrients and pesticides) losses by surface runoff, sediment
movement and leaching below the rootzone has prompted the
development of EPIC-PST. This model was developed by using
EPIC as a building block and adopting from the GLEAMS model
the pesticide related subroutines. EPIC-PST was evaluated by
a) validating the incorporation of GLEAMS pesticide
subroutines into EPIC; b) comparing chemical losses by runoff
and chemical concentration in the soil profile with observed
data from Ben Hur Research Farm, near Baton Rouge, Louisiana;
and c) comparing chemical concentration in the soil profile
with observed data from Dorminey farm near Tifton, Georgia. It
was concluded from the evaluation that the incorporation of
GLEAMS pesticide-related subroutines was successfully
accomplished. EPIC-PST overestimated total Atrazine loss in
runoff by 7% and underestimated total Metolachlor loss in
runoff by 8% when compared to the values observed at Ben Hur
Research Farm. For both sites, comparison of observed and
predicted pesticide concentrations in the soil profile has
shown that the model is apparently simulating faster movement
of chemical through the rootzone than that observed in the
field. However, the patterns in the changes of chemical
concentration with time were similar to the observed.
181 NAL Call. No.: S1.S68
Moisture transport in plastic coverings.
Sariev, A.L.; Kotovich, I.N.; Kobylyanskii, G.V.; Shukurov,
M.S. New York, N.Y. : Allerton Press; 1991.
Soviet agricultural sciences (5): p. 53-57; 1991. Translated
from: Vsesoiuznaia akademiia sel'skokhoziaistvennykh nauk.
Doklady, (5), p. 53-56. (20 AK1). Includes references.
Language: English; Russian
Descriptors: Greenhouses; Plastic cladding; Condensation;
Runoff; Mathematical models; Equations
182 NAL Call. No.: 56.9 SO3
Moment method applied to solute transport with binary and
ternary exchange. Leij, F.J.; Dane, J.H.
Madison, Wis. : The Society; 1992 May.
Soil Science Society of America journal v. 56 (3): p. 667-674;
1992 May. Includes references.
Language: English
Descriptors: Solutes; Movement in soil; Cation exchange;
Transport processes; Mathematical models; Simulation models;
Hydrodynamic dispersion
Abstract: When modeling transport of exchanging solutes in
soils, it is sometimes conveniently assumed that the solutes
interact linearly with the solid phase of the soil. In this
study, an attempt was made to quantify the influence of
nonlinear cation exchange on solute spreading with the moment
method. Theoretical expressions for the first four moments
were derived based on the equilibrium and physical
nonequilibrium models of the advection-dispersion equation
(ADE). Displacement experiments were conducted in which either
a NaCl pulse (binary exchange) or a pulse of KBr and NaBr
(ternary exchange) was applied to a CaBr2-saturated medium.
Values for the transport parameters were determined with
moment analysis and curve fitting. The observed breakthrough
curves were somewhat better reproduced with parameters
obtained from curve fitting than from the moment method.
However, the curve-fitting program produced some unrealistic
parameter estimates for the nonequilibrium model. A
disadvantage of the moment method was that the fourth-order
moment sometimes yielded unstable results for the
nonequilibrium model. Parameters form the anion displacement
were used to estimate the theoretical variance due to
hydrodynamic dispersion and nonequilibrium spreading for the
cation breakthrough curves. The difference between the
variance of the observed cation breakthrough curve and these
theoretical variances was used as an approximation of the
variance due to nonlinear exchange. Particularly for the
ternary exchange, the variance due to nonlinear exchange was
often several times greater than predicted according to the
transport model. The results enabled us to quantify errors in
dispersion coefficient (D) values directly determined from
cation-displacement experiments.
183 NAL Call. No.: 290.9 AM3PS (IR)
Movement of nonpoint-source contaminants through heterogeneous
soils. Tracy, J.C.
New York, N.Y. : American Society of Civil Engineers; 1992
Jan. Journal of irrigation and drainage engineering v. 118
(1): p. 88-103; 1992 Jan. Includes references.
Language: English
Descriptors: U.S.A.; Groundwater; Groundwater pollution;
Pollutants; Movement in soil; Transport processes; Seepage;
Soil water content; Simulation; Probabilistic models;
Deterministic models; Comparisons
184 NAL Call. No.: 56.8 AU7
Movement of solutes associated with intermittent soil water
flow. I. Tritium and bromide.
Scotter, D.R.; Tilman, R.W.
East Melbourne : Commonwealth Scientific and Industrial
Research Organization; 1991.
Australian journal of soil research v. 29 (2): p. 175-183;
1991. Includes references.
Language: English
Descriptors: Silt loam soils; Potassium bromide; Tritiated
water; Soil water movement; Solutes; Movement in soil;
Leaching; Diffusion; Equations; Hydrodynamic dispersion;
Diffusion models
185 NAL Call. No.: 292.9 AM34
Multicriterion analysis of groundwater contamination
management. Shafike, N.G.; Duckstein, L.; Maddock, T. III
Bethesda, Md. : American Water Resources Association; 1992
Jan. Water resources bulletin v. 28 (1): p. 33-43; 1992 Jan.
Includes references.
Language: English
Descriptors: Groundwater pollution; Groundwater; Water
management; Decision making; Water supply; Wastes; Costs;
Mathematical models
Abstract: Multicriterion decision making (MCDM) techniques
were used to analyze a groundwater contamination management
problem from the viewpoint of conflicting multiple objectives.
The groundwater management model was used to find a compromise
strategy for trading off fresh water supply, containment of
the waste, and total pumping cost in a hypothetical confined
aquifer affected by previous waste disposal action. A
groundwater flow model was used to formulate the hydraulic
constraints. A linear system model was used to describe
drawdown and velocity as functions of the decision variables
which were pumping rates. The model determines the pumping
location and rates. A modified epsilon-constraint method was
used to generate the set of nondominated solutions which were
the alternative compromise strategies. Three different MCDM
techniques, Compromise programming (CP), ELECTRA II and MCQA
II, were used to select a "satisficing" alternative. Analysis
of the results showed that, although these techniques follow
different principles, the same preferred strategies were
reached. Also, it was noticed that maintaining high
groundwater velocities is expensive and difficult. In order to
meet a two year target date, large amounts of water had to be
pumped. Therefore, rapid restoration results in large pumping
volumes and high costs.
186 NAL Call. No.: HD1.A3 A
multi-objective dynamic programming model for evaluation of
agricultural management systems in Richmond County, Virginia.
Zhu, M.; Taylor, D.B.; Sarin, S.C.
Essex : Elsevier Applied Science Publishers; 1993.
Agricultural systems v. 42 (1/2): p. 127-152; 1993. In the
special issue: Application of dynamic optimization techniques
to agricultural problems / edited by C.R. Taylor. Includes
references.
Language: English
Descriptors: Virginia; Legumes; Farm management; Farming
systems; Dynamic programming; Simulation models; Economic
impact; Environmental impact; Nitrogen fertilizers
187 NAL Call. No.: 290.9 AM32T
Multiobjective parameter estimation for hydrologic models--
multiobjective programming.
Yan, J.; Haan, C.T.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 May. Transactions of the ASAE v. 34 (3): p.
848-856; 1991 May. Includes references.
Language: English
Descriptors: Oklahoma; Hydrology; Precipitation; Problem
solving; Programming; Runoff; Simulation models; Watershed
management
Abstract: A procedure for parameter estimation in
multipurpose hydrologic models based on multiobjective
programming is developed. The procedure helps overcome a
problem which often occurs using traditional parameter
estimation techniques-producing parameters that are good with
respect to one objective but poor in terms of other
objectives. The proposed method was tested using a
precipitation runoff modeling system. The multiobjective
function used had three objectives for estimating four
parameters. It is shown that substantial improvement in
parameter estimates can be obtained using the tested method.
188 NAL Call. No.: QH540.N3
Multiphase contaminants in natural permeable media: various
modeling approaches.
Corapcioglu, M.Y.; Panday, S.
Berlin, W. Ger. : Springer-Verlag; 1993.
NATO ASI series : Series G : Ecological sciences v. 32: p.
191-220; 1993. In the series analytic: Migration and fate of
pollutants in soils and subsoils / edited by D. Petruzzelli
and F.G. Helfferich. Proceedings of the NATO Advanced Study
Institute, May 24-June 5, 1992, Maratea, Italy. Includes
references.
Language: English
Descriptors: Soil pollution; Groundwater pollution;
Pollutants; Transport processes; Mathematical models;
Equations; Organic compounds; Groundwater flow; Soil water
movement
189 NAL Call. No.: HD101.S6
Multiproduct production choices and pesticide regulation in
Georgia. McIntosh, C.S.; Williams, A.A.
Experiment, Ga. : The Association; 1992 Jul.
Southern journal of agricultural economics - Southern
Agricultural Economics Association v. 24 (1): p. 135-144; 1992
Jul. Includes references.
Language: English
Descriptors: Georgia; Pesticides; Uses; Groundwater pollution;
Regulations; Agricultural production; Supply response; Profit
functions; Econometric models; Economic impact; Taxes
Abstract: An increasing emphasis on surface and groundwater
quality and food safety may result in some form of pesticide
regulations. A restricted profit function model of Georgia
agriculture is used to examine the short-run effects of 2 and
5 percent reductions in all pesticides. Point estimates of
short-run impacts, along with their 90 percent confidence
intervals are presented.
190 NAL Call. No.: SF85.A1R32
National rangeland hydrology study.
Flanagan, M.
Denver, Colo. : Society for Range Management; 1992 Aug.
Rangelands v. 14 (4): p. 217-218; 1992 Aug.
Language: English
Descriptors: Nebraska; Texas; Kansas; Wyoming; Colorado;
Rangelands; Watersheds; Water quality; Vegetation; Erosion;
Runoff; Models; Databases; Data analysis; Hydrological data;
Plant communities
191 NAL Call. No.: QH540.N3
Nitrate ground-water modeling for agricultural and other
nonpoint sources. Kelly, W.E.; Curtis, B.; Adelman, D.
Berlin, W. Ger. : Springer-Verlag; 1991.
NATO ASI series : Series G : Ecological sciences v. 30: p.
97-113; 1991. In the series analytic: Nitrate contamination:
Exposure, consequence, and control / edited by I. Bogardi and
R.D. Kuzelka. Proceedings of the NATO Advanced Research
Workshop on Nitrate Contamination: Exposure, Consequences, and
Control, September 9-14, 1990, Lincoln, Nebraska. Includes
references.
Language: English
Descriptors: Nebraska; Nitrate; Nitrate fertilizers;
Groundwater pollution; Groundwater recharge; Farmland;
Simulation models
192 NAL Call. No.: QE1.E5
Nitrate pollution of groundwater in the Alsatian Plain
(France)--a multidisciplinary study of an agricultural area:
the Central Ried of the Ill River.
Bernhard, C.; Carbiener, R.; Cloots, A.R.; Froehlicher, R.;
Schenck, C.; Zilliox, L.
New York, N.Y. : Springer; 1992 Sep.
Environmental geology and water sciences v. 20 (2): p.
125-137; 1992 Sep. Includes references.
Language: English
Descriptors: France; Groundwater pollution; Nitrates; Maize;
Grain crops; Intensive cropping; Hydromorphic soils; Problem
solving; Grasslands; Geomorphology; Soil types; Agricultural
development; Land use; Models
193 NAL Call. No.: 292.8 W295
Nitrate reduction in an unconfined sandy aquifer: water
chemistry, reduction proceses, and geochemical modeling.
Postma, D.; Boesen, C.; Kristiansen, H.; Larsen, F.
Washington, D.C. : American Geophysical Union; 1991 Aug.
Water resources research v. 27 (8): p. 2027-2045; 1991 Aug.
Includes references.
Language: English
Descriptors: Nitrates; Soil pollution; Groundwater pollution;
Aquifers; Arable land; Heathland; Coniferous forests; Land
use; Transport processes; Reduction; Geochemistry; Models
Abstract: Nitrate distribution and reduction processes were
investigated in an unconfined sandy aquifer of Quaternary age.
Groundwater chemistry was studied in a series of eight
multilevel samplers along a flow line, deriving water from
both arable and forested land. Results show that plumes of
nitrate-contaminated groundwater emanate from the agricultural
areas and spread through the aquifer. The aquifer can be
subdivided into an upper 10- to 15-m thick oxic zone that
contains O2 and NO3(-), and a lower anoxic zone characterized
by Fe2+-rich waters. The redox boundary is very sharp, which
suggests that reduction processes of O2 and NO3(-) occur at
rates that are fast compared to the rate of downward water
transport. Nitrate-contaminated groundwater contains total
contents of dissolved ions that are two to four times higher
than in groundwater derived from the forested area. The
persistence of the high content of total dissolved ions in the
NO3(-) free anoxic zone indicates the downward migration of
contaminants and that active nitrate reduction is taking
place. Nitrate is apparently reduced to N2 because both
nitrite and ammonia are absent or found at very low
concentrations. Possible electron donors in the reduced zone
of the aquifer are organic matter, present as reworked brown
coal fragments from the underlying Miocene. and small amounts
of pyrite at an average concentration of 3.6 mmol/kg. Electron
balances across the redoxcline, based on concentrations of O2,
NO3(-), SO4(2-) and total inorganic carbon (TIC), indicate
that pyrite is by far the dominant electron donor even though
organic matter is much more abundant. Groundwater transport
and chemical reactions were modeled using the code PHREEQM,
which combines a chemical equilibrium model with a one-
dimensional mixing cell transport model. Only the vertical
component of the water transport was modeled since, in
contrast to rates along flow lines, the vertical rates are
close to constant as required by the one-dimensio
194 NAL Call. No.: 56.8 J822
Nitrogen leaching sensitivity to evapotranspiration and soil
water storage estimates in EPIC.
Benson, V.W.; Potter, K.N.; Bogusch, H.C.; Goss, D.; Williams,
J.R. Ankeny, Iowa : Soil and Water Conservation Society of
America; 1992 Jul. Journal of soil and water conservation v.
47 (4): p. 334-337; 1992 Jul. Includes references.
Language: English
Descriptors: U.S.A.; Water quality; Nitrogen; Leaching;
Movement in soil; Percolation; Soil water balance;
Evapotranspiration; Soil water; Storage; Estimation;
Methodology; Comparisons; Simulation models; Climatic zones;
Meteorological factors; Geographical distribution; Spatial
variation; Soil variability; Crop growth stage; Crop
management
195 NAL Call. No.: QH540.N3
Nitrogen modeling on a regional scale.
Rijtema, P.E.; Kroes, J.G.
Berlin, W. Ger. : Springer-Verlag; 1991.
NATO ASI series : Series G : Ecological sciences v. 30: p.
81-95; 1991. In the series analytic: Nitrate contamination:
Exposure, consequence, and control / edited by I. Bogardi and
R.D. Kuzelka. Proceedings of the NATO Advanced Research
Workshop on Nitrate Contamination: Exposure, Consequences, and
Control, September 9-14, 1990, Lincoln, Nebraska. Includes
references.
Language: English
Descriptors: Netherlands; Nitrate; Nitrate fertilizers; Water
pollution; Groundwater pollution; Simulation models; Computer
simulation; Runoff; Drainage; Farmland; Groundwater recharge
196 NAL Call. No.: TD419.R47
Nonpoint sources.
Line, D.E.; Arnold, J.A.; Osmond, D.L.; Coffey, S.W.; Gale,
J.A.; Spooner, J.; Jennings, G.D.
Alexandria, Va. : The Federation; 1993 Jun.
Water environment research v. 65 (4): p. 558-571; 1993 Jun.
Literature review. Includes references.
Language: English
Descriptors: Agricultural production; Agricultural chemicals;
Water pollution; Models
197 NAL Call. No.: TD419.R47
Nonpoint sources.
Spooner, J.; Coffey, S.W.; Brichford, S.L.; Arnold, J.A.;
Smolen, M.D.; Jennings, G.D.; Gale, J.A.
Alexandria, Va. : The Federation; 1991 Jun.
Research journal of the Water Pollution Control Federation v.
63 (4): p. 527-536; 1991 Jun. Literature review. Includes
references.
Language: English
Descriptors: Water pollution; Groundwater; Surface water; Land
use; Activity; Agricultural land; Forest soils; Urban areas;
Economics; Planning; Water quality; Water resources; Models;
Reviews
198 NAL Call. No.: QH540.N3
Numerical modeling of contaminant transport in groundwater.
Gambolati, G.; Paniconi, C.; Putti, M.
Berlin, W. Ger. : Springer-Verlag; 1993.
NATO ASI series : Series G : Ecological sciences v. 32: p.
381-410; 1993. In the series analytic: Migration and fate of
pollutants in soils and subsoils / edited by D. Petruzzelli
and F.G. Helfferich. Proceedings of the NATO Advanced Study
Institute, May 24-June 5, 1992, Maratea, Italy. Includes
references.
Language: English
Descriptors: Groundwater pollution; Pollutants; Transport
processes; Groundwater flow; Soil water movement; Equations;
Mathematical models
199 NAL Call. No.: 292.8 J82
Numerical simulation of infiltration and solute transport in
an S-shaped model basin by a boundary-fitted grid system.
Kinouchi, T.; Kanda, M.; Hino, M.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1991 Jan.
Journal of hydrology v. 122 (1/4): p. 373-406; 1991 Jan.
Includes references.
Language: English
Descriptors: Subsurface layers; Soil water movement; Solutes;
Transport processes; Rain; Simulation; Water; Discharge; Water
distribution; Velocity; Unsaturated flow; Capillary fringe;
Overland flow; Runoff; Groundwater; Mathematical models;
Simulation models
Abstract: The boundary-fitted grid method, which transforms a
complicated computational domain into a rectangular domain, is
applied for the moisture and solute transport problems in the
unsaturated soil layer of an S-shaped model hillslope. In the
transformed domain, the fundamental equations of moisture and
solute transport (i.e. the Richards equation and the Fickian
equation) can be easily discretized into the finite-difference
form. For three types of rainfall pattern (a unit rainfall,
two-unit successive rainfalls and two unit rainfalls with a
lag between them), hydrographs of total (pre-event and event
water) and event water discharges, contour lines of soil
moisture, pressure and total hydraulic head distributions, and
flow velocity vectors are compared. For a relatively thick
soil layer or for a relatively light rainfall, the capillary
fringe effect plays an important role, whereas for a
relatively thin soil layer or for a relatively heavy rainfall,
overland flow from a variable source area is superimposed on
the capillary-fringe-type runoff.
200 NAL Call. No.: 10 J822
Nutrient cycling and losses based on a mass-balance model in
grazed pastures receiving long-term superphosphate
applications in New Zealand. 1. Phosphorus. Nguyen, M.L.; Goh,
K.M.
Cambridge : Cambridge University Press; 1992 Aug.
The Journal of agricultural science v. 119 (pt.1): p. 89-106;
1992 Aug. Literature review. Includes references.
Language: English
Descriptors: New Zealand; Pastures; Phosphorus;
Superphosphates; Cycling; Leaching; Grazing effects; Nutrient
intake; Sheep; Simulation models; Literature reviews
201 NAL Call. No.: 10 J822
Nutrient cycling and losses based on a mass-balance model in
grazed pastures receiving long-term superphosphate
applications in New Zealand. 2. Sulphur. Nguyen, M.L.; Goh,
K.M.
Cambridge : Cambridge University Press; 1992 Aug.
The Journal of agricultural science v. 119 (pt.1): p. 107-122;
1992 Aug. Literature review. Includes references.
Language: English
Descriptors: New Zealand; Pastures; Fertilizer requirement
determination; Sulfur; Superphosphates; Cycling; Grazing
effects; Irrigated conditions; Leaching; Nutrient intake;
Sheep; Simulation models; Literature reviews
202 NAL Call. No.: 26 T754
Nutrient leaching loss from two contrasting cropping systems
in the humid tropics.
Seyfried, M.S.; Rao, P.S.C.
Guildford : Butterworth Scientific; 1991 Jan.
Tropical agriculture v. 68 (1): p. 9-18; 1991 Jan. Includes
references.
Language: English
Descriptors: Costa Rica; Cropping systems; Fertilizers;
Leaching; Losses from soil systems; Nutrients; Soil fertility;
Soil water balance; Simulation models; Humid tropics
203 NAL Call. No.: TD426.J68
One-dimensional immiscible displacement experiments.
Thomson, N.R.; Graham, D.N.; Farquhar, G.J.
Amsterdam : Elsevier; 1992 Aug.
Journal of contaminant hydrology v. 10 (3): p. 197-223; 1992
Aug. Includes references.
Language: English
Descriptors: Soil pollution; Immiscible displacement;
Prediction; Models; Groundwater pollution; Water table
204 NAL Call. No.: 292.8 J82
One-dimensional solute transport modelling in aggregated
porous media. 1. Model description and numerical solution.
Lafolie, F.; Hayot, C.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1993 Mar01.
Journal of hydrology v. 143 (1/2): p. 63-83; 1993 Mar01.
Special Issue: Modelling Flow and Transport in the Unsaturated
Zone: Scale Problems and Spatial Variability. Includes
references.
Language: English
Descriptors: Aggregates; Porosity; Macropores; Transport
processes; Particle size distribution; Simulation models
Abstract: A model for the simulation of solute transport in
aggregated porous media is presented. Transport by convection
and dispersion in the mobile phase, diffusion of solute inside
aggregates of arbitrary shapes and sizes, external mass
transfer resistance and linear adsorption are considered.
Depth-dependent properties of porous media and size
distribution of aggregates are accounted for. The problem of
solute diffusion inside arbitrarily shaped aggregates is
rigorously and easily treated by application of the Laplace
transformation and by introduction of an 'aggregate shape
function'. The whole system of equations is solved by: (1)
application of the Laplace transformation; (2) introduction of
the 'aggregate shape function' to reduce the transport problem
to a single ordinary differential equation whatever the
geometry of aggregates and the phenomena accounted for
(kinetic or instantaneous adsorption, external mass transfer
resistance); (3) finite-difference numerical solution of this
differential equation; (4) numerical inversion of the solution
obtained in the Laplace space. The main advantages of this
model are: (1) it incorporates, in a unique frame, the whole
variety of models so far proposed for transport modelling in
aggregated porous media (zero-, first- and higher order
approaches); (2) it simplifies the numerical treatment so that
there is no need to make simplifying assumptions about the
phenomena; (3) it provides an accurate solution using very
little computer time. The model is compared with previous
solutions, analytical or numerical, obtained for simple
aggregate geometries.
205 NAL Call. No.: 292.8 J82
One-dimensional solute transport modelling in aggregated
porous media. 2. Effects of aggregate size distribution.
Hayot, C.; Lafolie, F.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1993 Mar01.
Journal of hydrology v. 143 (1/2): p. 85-107; 1993 Mar01.
Special Issue: Modelling Flow and Transport in the Unsaturated
Zone: Scale Problems and Spatial Variability. Includes
references.
Language: English
Descriptors: Aggregates; Porosity; Particle size distribution;
Particle velocity; Transport processes; Diffusion;
Mathematical models
Abstract: The influence of various aggregate size
distributions on solute transport is analysed from a
quantitative and qualitative point of view. Uniform, normal,
log-normal and discrete aggregate size distributions are
considered. The model described in Part 1 is used to calculate
the breakthrough curves. The second-order moments and the sum
of squared differences are used to compare the responses
calculated with the distributions and with the mean radius.
The influence of a distribution depends on the velocity, and
consequently on the proportion of aggregates in situations of
local equilibrium or physical non-equilibrium. Breakthrough
curves calculated from normal distributions, whatever their
spread, do not differ significantly from those calculated
using the mean radii, while slightly skewed narrow
distributions generate significant differences. Thus, the
skewness and not only the spreading of the distribution seem
to modify the spreading of solute. The problem of using a
unique 'mean radius' instead of a distribution is also
considered. It is shown that the problem does not have a
simple answer. For a given distribution, the existence of an
acceptable mean radius depends strongly on the contrast
between the mobile phase residence time and the distribution
of characteristic diffusion times. Also, intuitively,
acceptable mean radii are more easily found for narrow
distributions. In most cases, it appears that a mean radius
cannot be used instead of the distribution. The analysis of
the way the distributions modify the breakthrough curves
suggests that simple bimodal distributions presenting fast-
and slow-reacting sites could be used in lieu of complete
distributions.
206 NAL Call. No.: 280.8 J822
The on-farm costs of reducing groundwater pollution.
Johnson, S.L.; Adams, R.M.; Perry, G.M.
Ames, Iowa : American Agricultural Economics Association; 1991
Nov. American journal of agricultural economics v. 73 (4): p.
1063-1073; 1991 Nov. Includes references.
Language: English
Descriptors: Oregon; Groundwater pollution; Nitrates; Economic
impact; Farm management; Crop yield; Simulation models; Farm
income; Costs; Farm inputs; Taxes; Dynamic models
Abstract: Agricultural chemicals are a source of groundwater
pollution in some areas. Regulatory options to reduce such
nonpoint pollution imply costs to producers. By integrating
plant simulation, hydrologic, and economic models of farm-
level processes, this study evaluates on-farm costs of
strategies to reduce nitrate groundwater pollution. The
empirical focus is on intensively managed, irrigated farms in
the Columbia Basin of Oregon. Results suggest that changes in
timing and application rates of nitrogen and water reduce
nitrate pollution with little loss in profits. Once such
practices are adopted, further reductions in nitrates can be
achieved only at increasing costs to producers.
207 NAL Call. No.: 292.8 W295
Optimal data acquisition strategy for the development of a
transport model for groundwater remediation.
Tucciarelli, T.; Pinder, G.
Washington, D.C. : American Geophysical Union; 1991 Apr.
Water resources research v. 27 (4): p. 577-588; 1991 Apr.
Includes references.
Language: English
Descriptors: Groundwater; Water quality; Water management;
Costs; Measurement; Stochastic models; Simulation models
Abstract: The reliability of groundwater quality management
algorithms is limited in large part by the uncertainty present
in the model parameters. Because the field parameter
measurement costs and the remediation costs must be supplied
by the same financial source, the classical optimization
procedure does not minimize the real total remediation
investment. This research presents an algorithm able to find
the total minimum for the sum of both the measurement and the
pumping costs. A chance-constrained technique is used to cast
the optimization problem in stochastic form, relating the
concentration covariance matrix to the log-transmissivity
covariance matrix by means of the transport equations and a
first-order approximation for the uncertainty. The simulation
model solves the steady state flow equations on a finite
element triangular mesh and the transport equations using the
backward method of characteristics. The resulting nonlinearly
constrained optimization problem is solved using the quasi-
linearity algorithm; this algorithm is designed to find a good
initial point for the local minimum search when the feasible
domain is not convex.
208 NAL Call. No.: aS21.R44A7
Opus: an integrated simulation model for transport of
nonpoint-source pollutants at the field scale: volume I.
Documentation.
Smith, R.E.
Beltsville, Md. : The Service; 1992 Jul.
ARS - U.S. Department of Agriculture, Agricultural Research
Service (98): 135 p.; 1992 Jul. Includes references.
Language: English
Descriptors: Pollution; Pollutants; Transport processes;
Movement in soil; Hydrology; Computer simulation; Simulation
models; Water flow; Meteorological factors; Growth models
209 NAL Call. No.: 292.8 W295 A
partial contributing area model for linking rainfall
simulation data with hydrographs of a small arid watershed.
Ben-Asher, J.; Humborg, G.
Washington, D.C. : American Geophysical Union; 1992 Aug.
Water resources research v. 28 (8): p. 2041-2047; 1992 Aug.
Includes references.
Language: English
Descriptors: Mali; Watersheds; Runoff water; Rain; Water
harvesting; Measurement; Prediction; Simulation; Satellite
imagery; Remote sensing; Catchment hydrology; Semiarid zones
Abstract: Four years of runoff measurement (29 events) in
Kangussano, Mali, were analyzed on the basis of the partial
area contribution concept. The study region is semiarid and
the use of runoff water to satisfy crop consumption is of high
importance. A first-order basin which included two flow
channels draining an area of 1.14 X 10(6) ha (1.14 km(2)) was
used for this purpose. The objective of this study was to
develop and test a conceptual model to predict runoff on
natural catchments of about this size. The model assumes that
a basin is composed of a large number of pixels (satellite
picture elements). Each pixel covers an area of 900 m(2). The
hydraulic properties of a representative pixel are determined
by runoff simulation experiments. The model calculates the
number of runoff generating pixels at a given time and rain
depth. The areal runoff is a product of these two factors.
Analysis of satellite images from LANDSAT and SPOT indicated
similarities of soil cover complexes between the study area
and an experimental area in Upper Volta. Results of runoff
simulation from this area were adapted for the study area and
used for the calculations. A good agreement between predicted
and measured contributing area was obtained when the number of
runoff generating pixels was 80 pixels/mm effective rain.
Predicted and measured hydrographs were also in good
agreement. It was therefore concluded that the model can
satisfactorily predict actual hydrographs from data generated
by rainfall-runoff simulators. Dividing the watershed to
surface elements of pixel's size makes the model capable of
linking remote sensing information with simulation data in
order to predict areal runoff.
210 NAL Call. No.: 292.8 W295
Partitioning solute transport between infiltration and
overland flow under rainfall.
Havis, R.N.; Smith, R.E.; Adrian, D.D.
Washington, D.C. : American Geophysical Union; 1992 Oct.
Water resources research v. 28 (10): p. 2569-2580; 1992 Oct.
Includes references.
Language: English
Descriptors: Pollutants; Solutes; Transport processes;
Infiltration; Overland flow; Rain; Surface water; Soil depth;
Interactions; Mathematical models; Field experimentation
Abstract: Solute transport from soil to overland flow is an
important source of nonpoint pollution and was investigated
through tracer studies in the laboratory and at an outdoor
laboratory catchment. The depth of surface water interaction
with soil, defined as the mixing zone is a useful value for
approximate estimation of potential solute transport into
surface water under rainfall. It was measured in the
laboratory for a noninfiltration case (0.90 to 1.0 cm) and
estimated through mass balance modeling for an infiltration
case (0.52 and 0.73 cm). At an outdoor laboratory catchment,
mixing zones were calculated through calibration of a
numerical model that describes unsteady, uniform, infiltration
and chemical transport. Overland flow was simulated using
kinematic wave theory. Mixing zone depths ranged from 0.47 to
1.02 cm and were a linear function of rainfall intensity.
Also, the fraction of solute present in the mixing zone at the
time of ponding which was extracted into overland flow was a
linear function of the initial soil moisture content. A steady
state analytical approximation of the solute transport model
was also developed which overpredicted solute transport into
overland flow by 1 to 60%.
211 NAL Call. No.: 290.9 AM32T
PATS: pesticide availability and transfer simualtor.
Kenimer, A.L.; Mitchell, J.K.; Bode, L.E.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 May. Transactions of the ASAE v. 35 (3): p.
841-853; 1992 May. Includes references.
Language: English
Descriptors: Alachlor; Terbufos; Pesticides; Absorption;
Availability; Computer software; Losses from soil systems;
Runoff; Simulation models
Abstract: A computer model was developed to simulate the
availability of pesticides in the soil matrix and uptake of
these pesticides into overland flow. The Pesticide
Availability and Transfer Simulator, PATS, accounts for the
distribution of chemical within soil, adsorption kinetics, and
chemical release from soil to overland flow. PLIERS, Pesticide
Losses In Erosion and Runoff Simulator, was used to simulate
surface transport of pesticides. Hydrologic data required by
PATS and PLIERS were generated by the distributed parameter
hydrologic model ANSWERS. PLIERS was enhanced through the
incorporation of PATS. Performance of enhanced model was
evaluated by comparing model predictions to observed data.
PATS-enhanced PLIERS dissolved pesticide loss predictions were
similar to predictions made with PLIERS alone and were in
reasonably good agreement with observed data. PATS-enhanced
PLIERS adsorbed pesticide loss predictions were frequently
lower than observed losses, but were generally closer to
observed losses than were PLIERS adsorbed pesticide loss
predictions.
212 NAL Call. No.: 100 SO82 (3)
Pesticide, nutrient and salt movement through the root zone.
Carlson, C.G.
Brookings, S.D. : The Station; 1991.
TB - Agricultural Experiment Station, South Dakota State
University (97): 6 p. (soil PR 90-41); 1991. Includes
references.
Language: English
Descriptors: South Dakota; Pesticides; Nutrients; Root zone
flux; Groundwater pollution; Models
213 NAL Call. No.: SB610.W39
Pesticide runoff simulations: long-term annual means vs. event
extremes?. Leonard, R.A.; Truman, C.C.; Knisel, W.G.; Davis,
F.M.
Champaign, Ill. : The Society; 1992 Jul.
Weed technology : a journal of the Weed Science Society of
America v. 6 (3): p. 725-730; 1992 Jul. Paper presented at a
Symposium on the, "Role of Modeling in Regulatory Affairs," at
the Weed Science Society of America, February 4, 1991,
Louisville, Kentucky. Includes references.
Language: English
Descriptors: Simulation models; Pesticides; Runoff; Losses
from soil; Rain; Simulation
214 NAL Call. No.: QD241.T6
Pesticide transport modelling in soil for risk assessment of
groundwater contamination.
Matthies, M.; Behrendt, H.
London : Gordon and Breach Science Publishers; 1991.
Toxicological and environmental chemistry v. 31/32: p.
357-365; 1991. Includes references.
Language: English
Descriptors: 2,4,5-t; Pesticide residues; Movement in soil;
Soil water movement; Groundwater pollution
Abstract: The risk of groundwater contamination with
pesticides applied to soil surface depends on the soil
properties, the agricultural practices, the climatic
influences, and on the properties of the pesticides
themselves. The EXSOL model was developed for the simulation
of the transport and fate of pesticides and organic in soils.
The dynamics of mobility, accumulation and degradation can be
studied under various soil and climatic conditions. Transient
water flow is provided from a simulation model of the field
water balance. The percentages of the herbicide 2,4-5-
trichlorophenoxyacetic acid in a luvisol soil after a single
application in summer are compared with model calculations
using sorption coefficients from laboratory column studies.
The calculated percentages lie within the measured range,
except for those in the deeper soil layer. The underestimation
can be explained with preferential flow in macropores which
may have occurred during the heavy rainfall six days after
application.
215 NAL Call. No.: HD1773.A2N6
Physical and economic model integration for measurement of the
environmental impacts of agricultural chemical use.
Antle, J.M.; Capalbo, S.M.
Morgantown, W.Va. : The Northeastern Agricultural and Resource
Economics Association; 1991 Apr.
Northeastern journal of agricultural and resource economics v.
20 (1): p. 68-82; 1991 Apr. Paper submitted in response to
call for papers on the theme "The Effects of Agricultural
Production on Environmental Quality.". Includes references.
Language: English
Descriptors: Groundwater; Surface water; Water quality;
Agricultural chemicals; Usage; Environmental impact;
Measurement; Agricultural production; Cost benefit analysis;
Models
216 NAL Call. No.: S601.A34
Potential contribution of ploughed grassland to nitrate
leaching. Whitmore, A.P.; Bradbury, N.J.; Johnson, P.A.
Amsterdam : Elsevier; 1992 Apr.
Agriculture, ecosystems and environment v. 39 (3/4): p.
221-233; 1992 Apr. Includes references.
Language: English
Descriptors: England; Wales; Leaching; Nitrate nitrogen;
Nitrogen; Plowing; Grassland soils; Soil organic matter;
Losses from soil systems; Runoff water; Drinking water;
Mathematical models
217 NAL Call. No.: QD1.A45
Potential leaching of herbicides applied to golf course
greens. Smith, A.E.; Tillotson, W.R.
Washington, D.C. : The Society; 1993.
ACS Symposium series - American Chemical Society (522): p.
168-181; 1993. In the series analytic: Pesticides in urban
environments: Fate and significance / edited by K.D. Racke and
A.R. Leslie. Paper presented at the 203rd National Meeting of
the American Chemical Society, April 5-10, 1992, San
Francisco, California. Includes references.
Language: English
Descriptors: 2,4-d; Herbicide residues; Leaching; Golf
courses; Golf green soils; Cynodon dactylon; Mathematical
models; Simulation models
Abstract: A critical issue facing the turfgrass industry is
the environmental fate and safety of pesticides used in the
management of national facilities. The purpose of our research
program was to develop a data base for the determination of
the potential movement of pesticides from golf course greens
into potable aquifers. Lysimeters were developed, in the
greenhouse, for the measurement of herbicide leaching from
simulated greens. Data were obtained from lysimeters
containing 'Tifdwarf' bermudagrass maintained as simulated
greens and receiving treatments of the dimethylamine salt of
2,4-D as a split application at rates of 0.56 + 0.56 kg ae
ha-1 on a two week interval. Only minute quantities of 2,4-D
were detected in the effluent from the lysimeters containing
two mixtures of rooting media. These data were compared to the
estimated values obtained from the GLEAMS mathematical model
simulations using parameters independently determined to
describe the lysimeter system. The GLEAMS model overestimated
the actual data-values received from the lysimeter experiments
on the potential for 2,4-D to leach through both rooting-media
profiles.
218 NAL Call. No.: TC401.W27
The potential of runoff-farming in the Sahel region:
developing a methodology to identifiy suitable areas.
Tauer, W.; Prinz, D.; Vogtle, T.
Hingham, Mass. : Kluwer Academic Publishers; 1991.
Water resources management v. 5 (3/4): p. 281-287; 1991.
Includes references.
Language: English
Descriptors: West Africa; Runoff farming; Runoff irrigation;
Site selection; Crops; Water requirements; Soil; Water
storage; Capacity; Models
219 NAL Call. No.: 290.9 AM32T
Potential runoff quality effects of poultry manure slurry
applied to fescue plots.
Edwards, D.R.; Daniel, T.C.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 Nov. Transactions of the ASAE v. 35 (6): p.
1827-1832; 1992 Nov. Includes references.
Language: English
Descriptors: Arkansas; Poultry manure; Runoff; Soil
amendments; Water quality; Simulation models
Abstract: A 3 X 2 factorial experiment was conducted to
determine how quality of runoff from grassed areas amended
with poultry manure slurry is affected by slurry application
rate and rainfall intensity for storms occurring one day
following application. Poultry manure slurry was applied at
rates of 0, 220, and 879 kg N ha-1 to plots established with
fescue grass on a Captina silt loam soil. Simulated rainfall
was applied 24 h following slurry application at intensities
of 5 and 10 cm h-1 until runoff had occurred for a duration of
0.5 h. Flow-weighted composite runoff samples were collected
and analyzed for total Kjeldahl N, ammonia N, nitrate N, total
P, dissolved reactive P, chemical oxygen demand, total
suspended solids, and electrical conductivity. Effects of the
experimental variables on both runoff concentrations and mass
losses of slurry constituents were assessed by analyses of
variance. Increasing slurry application rate significantly
increased runoff concentrations of all slurry constituents
investigated except nitrate N. For the affected slurry
constituents, the relationships between runoff concentration
of the constituent and slurry application rate appeared to be
linear over the range of application rates used. Mass losses
of all slurry constituents except nitrate N significantly
increased with increases in both slurry application rate and
rainfall intensity. Relationships between mass losses and
slurry application rate also appeared to be linear for the
range of application rates used in the study.
220 NAL Call. No.: 290.9 AM3PS (IR)
Precipitation distributions and Green-Ampt runoff.
Van Mullem, J.A.
New York, N.Y. : American Society of Civil Engineers; 1991
Nov. Journal of irrigation and drainage engineering v. 117
(6): p. 944-959; 1991 Nov. Includes references.
Language: English
Descriptors: Montana; Drainage; Runoff; Water distribution;
Precipitation; Storms; Flow; Green and ampt equation;
Infiltration; Prediction; Models
221 NAL Call. No.: 56.9 SO3
Predicting cation mobility in kaolinitic media based on
exchange selectivities of kaolinite.
Gaston, L.A.; Selim, H.M.
Madison, Wis. : The Society; 1991 Sep.
Soil Science Society of America journal v. 55 (5): p.
1255-1261; 1991 Sep. Includes references.
Language: English
Descriptors: Louisiana; Hapludults; Kaolinite; Sand; Subsoil;
Cation exchange; Cation exchange capacity; Exchangeable
cations; Calcium; Magnesium; Exchangeable sodium; Spatial
distribution; Movement in soil; Transport processes;
Mathematical models; Adsorption; Soil solution; Soil water;
Potassium; Pores; Physicochemical properties; Prediction
Abstract: Predictive modeling of cation transport in soils
requires knowledge of the distribution of exchangeable species
between solution and adsorbed phases. Such distribution of
exchangeable species may be described with an exchange
selectivity coefficient. Typically, the selectivity
coefficient for any cation-exchange pair varies among soils.
If the exchange complex of a soil is dominated by one type of
exchanger, however, then the selectivity coefficient for that
soil may be similar in magnitude to that for the principal
mineral (or organic) constituent. Therefore, reasonably
accurate predictions of cation transport in that soil might be
obtained using exchange data for the dominant exchange
material. This study was undertaken to determine whether
exchange data for kaolinite could be successfully used in
predicting Ca, Mg, and Na retention during movement in a Mahan
series soil (clayey, kaolinitic, thermic Typic Hapludult).
Binary-exchange isotherms for Ca-Mg, Ca-Na, and Mg-Na were
generated for Ga-1 kaotinite (well crystallized). Selectivity
coefficients derived from these data were used to describe
cation exchange during miscible displacement through columns
of (i) kaolinite admixed with acid-washed sand and (ii) Mahan
soil. Use of the selectivity coefficients for kaotinite
provided good predictions of cation transport in the
kaolinite/sand mixture. Predictions for the kaolinitic Mahan
soil were not as good. The presence of small amounts of 2:1
minerals may have influenced the overall exchange behavior of
the Mahan soil. When the uncertainty in values for selectivity
coefficients and other exchange or transport parameters was
considered, however, the exchange selectivity data for
kaolinite could adequately describe cation transport in the
Mahan soil.
222 NAL Call. No.: 56.8 AU7
Predicting exchangeable cation distributions in soil by using
exchange coefficients and solution activity ratios.
Phillips, I.R.; Black, A.S.
East Melbourne : Commonwealth Scientific and Industrial
Research Organization; 1991.
Australian journal of soil research v. 29 (3): p. 403-414;
1991. Includes references.
Language: English
Descriptors: Exchangeable cations; Potassium; Magnesium;
Movement in soil; Distribution; Leaching; Prediction; Models;
Equilibrium; Soil solution; Soil water content
223 NAL Call. No.: 290.9 AM32T
Predicting runoff of water, sediment, and nutrients from a New
Zealand grazed pasture using CREAMS.
Cooper, A.B.; Smith, C.M.; Bottcher, A.B.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 Jan. Transactions of the ASAE v. 35 (1): p.
105-112; 1992 Jan. Includes references.
Language: English
Descriptors: New Zealand; Grassland management; Grazing
effects; Hydraulic conductivity; Losses from soil systems;
Prediction; Runoff; Water quality; Computers; Simulation
models
Abstract: The ability of the CREAMS model to predict loadings
of runoff, sediment and nutrients from a New Zealand grazed
pasture was evaluated. Before use, CREAMS was adapted to
better represent N and P cycling in grazed pastures and the
seasonal variation in hydraulic conductivity observed at the
site. There was a moderately strong relationship (r2 = 0.81)
between daily surface runoff volumes predicted by this
modified model and volumes measured at the site for 62 events
over a three and one half year period. Although the ability of
the model to predict daily losses of sediment and nutrients
was considerably less (r2 < 0.45), the model was always an
unbiased predictor. This unbiased predictive ability provides
good estimates of losses over longer time scales (e.g.,
seasonal) which is often sufficient when evaluating the
impacts of land use practices on water quality. The adapted
CREAMS model successfully simulated measured reductions in
edge-of-field losses of sediment and nutrient upon
installation of a vegetated filter strip. We conclude that
although CREAMS has limitations in representing the dynamics
of grazed pastures, it shows potential as a water quality
management tool in pastoral watersheds.
224 NAL Call. No.: QH545.A1E52
Predicting stream-water quality using catchment and soil
chemical characteristics.
Billett, M.F.; Cresser, M.S.
Essex : Elsevier Applied Science; 1992.
Environmental pollution v. 77 (2/3): p. 263-268; 1992. In the
special issue: Effects of acidic pollutants on the chemistry
of freshwater streams and lakes / edited by R. Harriman. Paper
presented at the "Fourth International Conference on Acidic
Deposition: Its Nature and Impacts," September 16-21, 1990,
Glasgow, Scotland. Includes references.
Language: English
Descriptors: Northern scotland; Eastern scotland; Soil
chemistry; Cation exchange; Prediction; Water quality;
Hydrogen ions; Acidity; Calcium ions; Streams; Watersheds;
Horizons; Simulation; Simulation models
225 NAL Call. No.: 292.8 W295
Prediction uncertainty in solute flux through heterogeneous
soil. Destouni, G.
Washington, D.C. : American Geophysical Union; 1992 Mar.
Water resources research v. 28 (3): p. 793-801; 1992 Mar.
Includes references.
Language: English
Descriptors: Solutes; Transport processes; Unsaturated flow;
Degradation; Surface layers; Soil depth; Hydraulic
conductivity; Soil zonation; Mathematical models
Abstract: The Lagrangian framework presented by Dagan et al.
(1992a) is used to analyze the uncertainty in predictions of
the field scale mass flux of solute through the unsaturated
zone. Transport of both nonreactive and degradable solutes is
investigated for input sources that are located at the soil
surface of fields with spatially variable hydraulic
conductivity at saturation. The variances of the solute flux
and accumulated mass, which quantify the corresponding
prediction uncertainties, are illustrated at an arbitrary
depth below the soil surface for different sizes and shapes of
the input domain, and for different flow and degradation
conditions. The greatest solute flux variances arise when the
expected breakthrough curve has a steep slope. The coefficient
of variation for the solute flux is minimum at the peak
arrival time of the expected breakthrough curve; this minimum
value is relatively insensitive to the assumed distribution
for solute travel time and to the loss rate coefficient for
degradable solute. The prediction uncertainty decreases with
increasing size of the input domain and is smaller for a
planar source than for a linear one. The relative uncertainty
in the total leached mass of degradable solute increases with
increasing loss rate coefficient.
226 NAL Call. No.: 290.9 AM32T
Predictive capabilities of erosion models for different storm
sizes. Bingner, R.L.; Mutchler, C.K.; Murphree, C.E.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 Mar. Transactions of the ASAE v. 35 (2): p.
505-513; 1992 Mar. Includes references.
Language: English
Descriptors: Mississippi; Erosion; Rain; Runoff; Sediment
yield; Simulation models; Slopes; Storms; Watersheds
Abstract: When conservation practices are evaluated for
erosion control effectiveness, the erosion or sediment yield
produced by all the various storms that occur throughout the
year should he considered. The Universal Soil Loss Equation
neglects storms less than 13 mm unless the storm includes
excessive rainfall intensities. Other erosion models have been
developed that can easily consider all sizes of storms. This
study evaluates the capability of several erosion models
(CREAMS, SWRRB, EPIC, ANSWERS, and AGNPS) to predict runoff
and erosion from rainfall events of 0 to 13, 13 to 25, 25 to
50, 50 to 75, and greater than 75 mm. Runoff and erosion were
simulated on three watersheds in Mississippi: a sloping upland
watershed, a flatland watershed, and a terraced watershed with
underground outlets. Results show that the models predicted a
linear relation of runoff and erosion with rainfall. However,
the slope of the model regressions varied widely from data
values. Only CREAMS and SWRRB were successful in predicting
annual average runoff and sediment yield within 20% of
measured amounts from the upland watershed and only SWRRB and
AGNPS were successful in prediction for the flatland
watershed. None of the models predicted within 20% of measured
amounts from the terraced watershed. In all cases, errors were
greatest for the larger storms.
227 NAL Call. No.: GB701.W375 no.92-4108
Preliminary results of the simulation of Oregon coastal basins
using Precipitation-Runoff Modeling System (PRMS).
Allen, Roderick L.; Laenen, Antonius
United States, Bureau of Land Management, Geological Survey
(U.S.) Portland, Or. : U.S. Dept. of the Interior, U.S.
Geological Survey ; Denver, CO : Books and Open-File Reports
Section [distributor],; 1993; I 19.42/4:92-4108.
vi, 99 p. : ill., maps ; 28 cm. (Water-resources
investigations report ; 92-4108). Shipping list no.: 93-0315-
P. Includes bibliographical references (p. 43-44).
Language: English; English
Descriptors: Hydrologic models; Runoff; Coasts
228 NAL Call. No.: 60.18 J82
Rangeland experiments to parameterize the water erosion
prediction project model: vegetation canopy cover effects.
Simanton, J.R.; Weltz, M.A.; Larsen, H.D.
Denver, Colo. : Society for Range Management; 1991 May.
Journal of range management v. 44 (3): p. 276-282; 1991 May.
Includes references.
Language: English
Descriptors: Rangelands; Water erosion; Prediction; Simulation
models; Rain; Interception; Canopy; Ground vegetation;
Infiltration; Runoff; Losses from soil systems; Prairies;
Steppes; Soil types; Edaphic factors; Site factors
Abstract: The Water Erosion Prediction Project (WEPP) is a
new water erosion prediction technology being developed by the
USDA-Agricultural Research Service to replace the Universal
Soil Loss Equation. Rangeland field experiments were designed
to parameterize the WEPP rangeland erosion model. Included in
the field experiments were plot treatments designed to
separate direct from indirect effects of vegetation canopy on
runoff and soil erosion. Nine rangeland sites from a wide
range of soil and vegetation types were evaluated using
rainfall simulation techniques. Natural versus clipped
treatment surface characteristics and runoff and erosion
responses were compared using regression analyses. These
analyses showed that there were no significant differences
between natural and clipped plot surface characteristics,
runoff ratios, final infiltration rates, or initial rainfall
abstractions. Erosion rates were different between treatments
with the clipped plots having slightly less erosion than the
natural plots. Results indicated that, under the rainfall
conditions simulated, canopy cover was not directly
contributing to initial abstractions through rainfall
interception loss or significantly affecting runoff or
erosion.
229 NAL Call. No.: QD241.T6
Regression models for some solute distribution equilibria in
the terrestrial environment.
Noegrohati, S.; Hammers, W.E.
Reading : Gordon and Breach Science Publishers; 1992.
Toxicological and environmental chemistry v. 34 (2/4): p.
175-185; 1992. Includes references.
Language: English
Descriptors: Organochlorine insecticides; Soil; Sorption;
Solvents; Leaching; Regression analysis
Abstract: Sorption coefficients (K(p)) of several
organochlorine insecticides (OCs) in volcanic ash silt from
Central Java are presented. Selected experimental and
estimated octanol-water partition coefficient (P) values are
used to study log-log regressions with K(p) data collected
from the literature (PAHs, chlorophenols, phenylureas, chloro-
s-triazines, carbamates and organophosphorus insecticides) and
those of the OCs determined in the present study. Leaching
distances and bioactivities in soil are correlated with the
K(p) values of the pesticides, and with the organic matter and
the water content of the soil.
230 NAL Call. No.: HC79.P55J6
Regulating agricultural contamination of groundwater through
strict liability and negligence legislation.
Wetzstein, M.E.; Centner, T.J.
Orlando, Fla. : Academic Press; 1992 Jan.
Journal of environmental economics and management v. 22 (1):
p. 1-11; 1992 Jan. Includes references.
Language: English
Descriptors: Georgia; Idaho; Iowa; Minnesota; Vermont;
Groundwater pollution; Environmental legislation; Regulations;
Legal liability; Game theory; Dynamic models; Agricultural
chemicals
Abstract: New state and national legislation attempts to
limit the liability of agricultural chemical users by
emasculating existing strict liability standards and replacing
them with negligence standards. The allocation of
contamination costs and precaution level between producers and
victims of contamination associated with these alternative
legislative standards is investigated. The analysis employed
is a dynamic game theoretic framework considering moral
hazard. Based on this analysis, a new institutional response
is recommended to assign property rights based upon propensity
and severity of injury and to require victim precaution.
231 NAL Call. No.: 292.8 W295
The regulation of groundwater quality with delayed responses.
Kim, C.S.; Hostetler, J.; Amacher, G.
Washington, D.C. : American Geophysical Union; 1993 May.
Water resources research v. 29 (5): p. 1369-1377; 1993 May.
Includes references.
Language: English
Descriptors: Groundwater pollution; Pollution control;
Groundwater; Water quality; Regulations; Dynamic models;
Algorithms; Nitrogen fertilizers; Farm inputs; Leachates;
Nitrates; Usage; Costs; Agricultural policy
Abstract: This research develops a dynamic model of input
regulation in the presence of externalities that do not occur
simultaneously with input use. The model is formulated to
study the regulation of firms that apply fertilizer, where
leachate from the application of fertilizer accumulates in
groundwater over time. In the model we show the derivation of
an optimal nitrogen user fee and the consequences of
regulatory design when time lags between nitrogen application
and nitrate contamination are present. This research also
responds to the need of developing a general solution
algorithm for an optimal control model when the control
variable exhibits a delayed response. A multistage solution
algorithm presented in this paper is different from other
studies in that a typical relationship is not assumed for the
state and adjoint variables.
232 NAL Call. No.: HC79.P55J6
The regulation of non-point source pollution under imperfect
and asymmetric information.
Cabe, R.; Herriges, J.A.
Orlando, Fla. : Academic Press; 1992 Mar.
Journal of environmental economics and management v. 22 (2):
p. 134-146; 1992 Mar. Includes references.
Language: English
Descriptors: Pollution; Control methods; Agricultural
chemicals; Information; Costs; Reliability; Bayesian theory;
Regulations; Taxes; Farmers' attitudes; Beliefs; Mathematical
models
Abstract: This paper develops a Bayesian framework for
discussing the role of information in the design of non-point-
source pollution control mechanisms. An ambient concentration
tax is examined, allowing for spatial transport among multiple
zones. Imposition of the tax requires costly measurement of
concentrations in selected zones, and the selection of zones
for measurement must be undertaken without perfect information
regarding several parameters of the problem. Potentially
crucial information issues discussed include: (a) the impact
of asymmetric priors regarding fate and transport. (b) the
cost of measuring ambient concentration, and (c) the optimal
acquisition of information regarding fate and transport.
233 NAL Call. No.: 10 J822
Relating the nitrogen fertilizer needs of winter wheat crops
to the soil's mineral nitrogen. Influence of the downward
movement of nitrate during winter and spring.
Addiscott, T.M.; Darby, R.J.
Cambridge : Cambridge University Press; 1991 Oct.
The Journal of agricultural science v. 117 (pt.2): p. 241-249;
1991 Oct. Includes references.
Language: English
Descriptors: Triticum aestivum; Fertilizer requirement
determination; Leaching; Mineralization; Nitrates; Nitrogen
fertilizers; Simulation models; Soil fertility
234 NAL Call. No.: QH540.N3
Risk analysis for water supply from a river polluted by
nitrate runoff. Plate, E.J.; Duckstein, L.
Berlin, W. Ger. : Springer-Verlag; 1991.
NATO ASI series : Series G : Ecological sciences v. 30: p.
67-79; 1991. In the series analytic: Nitrate contamination:
Exposure, consequence, and control / edited by I. Bogardi and
R.D. Kuzelka. Proceedings of the NATO Advanced Research
Workshop on Nitrate Contamination: Exposure, Consequences, and
Control, September 9-14, 1990, Lincoln, Nebraska. Includes
references.
Language: English
Descriptors: German federal republic; Nitrate; Nitrate
fertilizers; Water pollution; Rivers; Runoff; Water quality;
Risk; Drainage; Farmland; Stochastic models
235 NAL Call. No.: QH540.N3
Risk analysis of groundwater contamination.
Ganoulis, J.
Berlin, W. Ger. : Springer-Verlag; 1993.
NATO ASI series : Series G : Ecological sciences v. 32: p.
455-474; 1993. In the series analytic: Migration and fate of
pollutants in soils and subsoils / edited by D. Petruzzelli
and F.G. Helfferich. Proceedings of the NATO Advanced Study
Institute, May 24-June 5, 1992, Maratea, Italy. Includes
references.
Language: English
Descriptors: Victoria; Groundwater pollution; Pollutants;
Hydrodynamics; Transport processes; Groundwater flow;
Aquifers; Mathematical models; Risk; Saline water; Irrigation
water
236 NAL Call. No.: QH540.N3 A
river water quality management model for Canal de Isabel. II.
Comunidad de Madrid.
Cubillo, F.; Rodriguez, B.
Berlin, W. Ger. : Springer-Verlag; 1991.
NATO ASI series : Series G : Ecological sciences v. 26: p.
375-385; 1991. In the series analytic: Decision support
systems: Water resources planning / edited by D.P. Loucks and
J.R. da Costa. Proceedings of the NATO Advanced Research
Workshop on Computer-Aided Support Systems for Water
Resources, Research and Management, September 24-28, 1990,
Ericeira, Portugal. Includes references.
Language: English
Descriptors: Spain; Water management; Rivers; Water quality;
Water pollution; Waste water treatment; Simulation models;
Computer simulation; Computer software
237 NAL Call. No.: SB610.W39
The role of sensitivity analysis in groundwater risk modeling
for pesticides. Fontaine, D.D.; Havens, P.L.; Blau, G.E.;
Tillotson, P.M. Champaign, Ill. : The Society; 1992 Jul.
Weed technology : a journal of the Weed Science Society of
America v. 6 (3): p. 716-724; 1992 Jul. Paper presented at a
Symposium on the, "Role of Modeling in Regulatory Affairs," at
the Weed Science Society of America, February 4, 1991,
Louisville, Kentucky. Includes references.
Language: English
Descriptors: Simulation models; Pesticides; Leaching;
Groundwater; Methodology
238 NAL Call. No.: 56.8 J822
Runoff characteristics of sagebrush rangelands: modeling
implications. Wilcox, B.P.; Seyfried, M.S.; Cooley, K.R.;
Hanson, C.L.
Ankeny, Iowa : Soil and Water Conservation Society of America;
1991 Mar. Journal of soil and water conservation v. 46 (2): p.
153-158; 1991 Mar. Includes references.
Language: English
Descriptors: Rangelands; Runoff; Computer simulation;
Prediction; Watersheds; Precipitation
239 NAL Call. No.: 292.8 W295
Runoff contamination by soil chemicals: time scale approach.
Wallach, R.
Washington, D.C. : American Geophysical Union; 1991 Feb.
Water resources research v. 27 (2): p. 215-223; 1991 Feb.
Includes references.
Language: English
Descriptors: Runoff; Runoff water; Chemicals; Contamination;
Overland flow; Soil solution; Transport processes; Profiles;
Mathematical models
Abstract: Two mass balance equations were used to model the
transfer of dissolved chemicals from the soil solution to the
surface runoff water and transport of these chemicals to the
field outlet end. One mass balance equation is written for the
chemicals dissolved in the overland water, and the other for
the chemicals within the soil profile. The chemical input into
the surface runoff water is by the rate-limited convective
mass transfer process. Two time scales are isolated: the slow
time scale represents the diffusion-based mass transfer
process and the fast time scale represents the convective
transport of dissolved chemicals by overland flow. Scaling the
mass balance equations for the slow time scale yields a small
parameter, which multiplies the time derivative of the mass
balance equation written for the overland flow, providing a
singular perturbation problem. By using the method of matched
asymptotic expansion, an inner and outer problem is formulated
and solved for each order of approximation. A single composite
expansion, uniformly valid over the entire domain, is derived
analytically. This approximated solution was compared with an
exact analytical solution for the case in which chemicals are
initially uniformly distributed throughout a semi-infinite
soil profile. The time scale method was then used to solve a
more complicated problem in which chemicals are initially
distributed within a certain soil surface layer of a semi-
infinite soil profile.
240 NAL Call. No.: 290.9 AM32T
Runoff curve numbers determined by three methods under
conventional and conservation tillages.
Yoo, K.H.; Yoon, K.S.; Soileau, J.M.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1993 Jan. Transactions of the ASAE v. 36 (1): p.
57-63; 1993 Jan. Includes references.
Language: English
Descriptors: Alabama; Runoff; Tillage; Traditional farming;
Conservation tillage; Gossypium; Mathematical models
Abstract: Event-based rainfall and the associated runoff data
collected from a small watershed planted to cotton were
analyzed to determine effects of two tillage systems on SCS
runoff curve numbers. A tillage study was conducted for six
years on a 3.8 ha watershed planted to cotton in the Limestone
Valley region of northern Alabama. The tillage included three
years of conventional (CvT), followed by three years of
conservation tillage (CsT). Soils of the watershed are Decatur
(clayey, kaolinitic, thermic Rhodic Paleudults) and Emory silt
loam (fine-silty, siliceous, thermic Fluventic Umbric
Dystrochrepts) which are classified in Hydrologic Soil Group
B. Curve numbers (CN) were determined by the SCS method and a
method developed assuming a log-normal probability
distribution of potential maximum retention, S. The published
CN of the average soil moisture condition or antecedent
moisture condition II (AMC II) for the study site are 78 and
75 for CvT and CsT, respectively, which are recommended in
many watershed/water quality computer simulation models such
as CREAMS and AGNPS. The results showed that CN of AMC II (CN-
II) calculated by the log-normal method were 83 and 88 for CvT
and CsT, respectively. These were slightly higher than those
calculated by the SCS method which were 82 for CvT and 86 for
CsT. The calculated CN-II values were higher than the
published CN-II values but the order of magnitude was
reversed.
241 NAL Call. No.: 290.9 AM32T
Runoff curve numbers for the southern High Plains.
Hauser, V.L.; Jones, O.R.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 Jan. Transactions of the ASAE v. 34 (1): p.
142-148; 1991 Jan. Includes references.
Language: English
Descriptors: Southern plains states of U.S.A.; Runoff; Surface
water; Water erosion; Water quality; Watersheds; Mathematical
models; Rain; Soil conservation
Abstract: Rainfall produces significant amounts of surface
runoff from cultivated drylands of the western Great Plains.
Currently, engineers must extrapolate runoff data from more
humid regions to estimate runoff from farm fields. Runoff data
are now available from a 32-year record in the semiarid,
western Great Plains. We derived curve numbers (CN) for the
Soil Conservation Service curve number method for three field-
sized watersheds that were dryland-farmed in a wheat-sorghum-
fallow crop sequence. The watershed soils are classified in
hydrologic group D. The CNs for wheat and sorghum should be 79
and 82, respectively (handbook CN are both 80). The single
handbook CN for fallow (90) is too high; it should be 77 for
fallow after wheat and 82 for fallow after sorghum. These new
CNs should improve computer model predictions of runoff,
erosion and water quality, and provide more accurate estimates
of runoff volume for use in designing conservation structures,
water supply, flood control, and numerous other uses.
242 NAL Call. No.: 60.18 J82
Runoff prediction from sagebrush rangelands using water
erosion prediction project (WEPP) technology.
Wilcox, B.P.; Sbaa, M.; Blackburn, W.H.; Milligan, J.H.
Denver, Colo. : Society for Range Management; 1992 Sep.
Journal of range management v. 45 (5): p. 470-474; 1992 Sep.
Includes references.
Language: English
Descriptors: Artemisia tridentata; Rangelands; Grassland
management; Water erosion; Erosion control; Runoff;
Prediction; Simulation models; Mathematical models
Abstract: Runoff prediction is an important component of any
process-based soil erosion model. In this paper we evaluate
the runoff prediction capabilities of a new soil erosion
model, WEPP, on sagebrush rangelands. Particular attention was
given to the parameter estimation techniques used in WEPP to
predict infiltration. Runoff volume predicted by WEPP is based
on the Green and Ampt infiltration equation. Predicted runoff
was compared to observed runoff from 90 large plot rainfall
simulation experiments on sagebrush rangelands. There was a
poor correlation between predicted and observed runoff when
the Green and Ampt parameters were estimated using the
parameter estimation techniques. Runoff prediction was
improved when parameters were determined from field
measurements. Additional refinement of the Green and Ampt
parameterization techniques is needed for continued
improvement of WEPP.
243 NAL Call. No.: 56.8 SO3
Saline and sodic-saline soil reclamation: first order kinetic
model. Selassie, T.G.; Jurinak, J.J.; Dudley, L.M.
Baltimore, Md. : Williams & Wilkins; 1992 Jul.
Soil science v. 154 (1): p. 1-7; 1992 Jul. Includes
references.
Language: English
Descriptors: Saline sodic soils; Saline soils; Reclamation;
Leaching; Kinetics; Soil water movement; Saturated conditions;
Drained conditions; Salts in soil; Sodium; Solutes; Movement
in soil; Electrical conductivity; Exchangeable sodium;
Adsorption; Ratios; Ion exchange; Diffusion
244 NAL Call. No.: 56.8 SO3 A
scaled sorption model validated at the column scale to predict
cadmium contents in a spatially variable field soil.
Boekhold, A.E.; Zee, S.E.A.T.M. van der
Baltimore, Md. : Williams & Wilkins; 1992 Aug.
Soil science v. 154 (2): p. 105-112; 1992 Aug. Includes
references.
Language: English
Descriptors: Netherlands; Spodosols; Arable soils; Polluted
soils; Cadmium; Sorption; Mathematical models; Validity; Soil
ph; Soil organic matter; Soil variability; Spatial variation;
Soil solution; Sorption isotherms; Transport processes
245 NAL Call. No.: SB610.W39
Screening procedure for soils and pesticides for potential
water quality impacts.
Goss, D.W.
Champaign, Ill. : The Society; 1992 Jul.
Weed technology : a journal of the Weed Science Society of
America v. 6 (3): p. 701-708; 1992 Jul. Paper presented at a
Symposium on the, "Role of Modeling in Regulatory Affairs," at
the Weed Science Society of America, February 4, 1991,
Louisville, Kentucky. Includes references.
Language: English
Descriptors: Pesticides; Losses from soil; Leaching; Water
quality; Groundwater pollution; Simulation models
246 NAL Call. No.: 292.8 J82
The seasonal variation of streamwater chemistry in three
forested Mediterranean catchments.
Pinol, J.; Avila, A.; Roda, F.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Dec.
Journal of hydrology v. 140 (1/4): p. 119-141; 1992 Dec.
Includes references.
Language: English
Descriptors: Spain; Watersheds; Broadleaved evergreen forests;
Streams; Water quality; Water content; Chemical properties;
Stream flow; Seasonal variation; Discharge; Solutes; Ions;
Soil water; Groundwater; Temperature; Catchment hydrology;
Mediterranean climate; Mathematical models
Abstract: Streamwater chemistry is described for three
streams draining undisturbed, evergreen broad-leaved forested
catchments on phyllites in NE Spain: two streams with no or
negligible flow in summer are located in the Prades massif,
and one perennial stream is in the wetter Montseny mountains.
Weekly data for a study period of 24 years are provided to (1)
describe the seasonal variations in streamwater chemistry, (2)
analyse the relationship between stream discharge and solute
concentrations using a two-component mixing model and (3)
search for patterns of temporal variation in stream solute
concentrations after discounting the effects of discharge. At
Prades, concentrations of all analysed ions, except NO3(-1),
showed marked seasonal variations in stream water, whereas at
Montseny only ions related to mineral weathering (HCO3(-1),
Na+, Ca2+ and Mg2+) showed strong seasonality. Ion
concentrations were more closely dependent on instantaneous
discharge at Montseny than at Prades. The residuals of the
relationship between solute concentrations and discharge
retained a strong seasonality at Prades, but not at Montseny.
These differences are related to the major hydrochemical
processes that determine the streamwater chemistry at each
site. The same processes are probably operative in the three
catchments, but are of varying relative importance. At
Montseny, the mixing of waters of different chemical
composition seems to be the major process controlling
streamwater chemistry, although the soilwater end-member
composition predicted by the mixing model applied did not
match the measured soilwater chemistry. In the drier Prades
catchments, the two major hydrochemical processes determining
the seasonal variation of streamwater chemistry are (1) the
restart of flow after the summer drought, which flushes out
the solutes accumulated during the dry period, and (2) the
seasonal changes in groundwater chemistry that result from the
interplay of water residence time, temperature and CO
247 NAL Call. No.: 292.8 W295
The second Las Cruces Trench experiment: experimental results
and two-dimensional flow predictions.
Hills, R.G.; Wierenga, P.J.; Hudson, D.B.; Kirkland, M.R.
Washington, D.C. : American Geophysical Union; 1991 Oct.
Water resources research v. 27 (10): p. 2707-2718; 1991 Oct.
Includes references.
Language: English
Descriptors: New Mexico; Soil water; Water flow; Tritium;
Bromide; Solutes; Transport processes; Infiltration;
Redistribution; Semiarid soils; Soil variability; Measurement;
Deterministic models; Prediction
Abstract: As part of a comprehensive field study designed to
provide data to test stochastic and deterministic models of
water flow and contaminant transport in the vadose zone,
several trench experiments were performed in the semiarid
region of southern New Mexico. The first trench experiment is
discussed by Wierenga et al. (this issue). During the second
trench experiment, a 1.2 m wide by 12 m long area on the north
side of and parallel to a 26.4 m long by 4.8 m wide by 6 m
deep trench was irrigated with water containing tracers using
a carefully controlled drip irrigation system. The irrigated
area was heavily instrumented with tensiometers and neutron
probe access tubes to monitor water movement, and with suction
samplers to monitor solute transport. Water containing tritium
and bromide was applied during the first 11.5 days of the
study. Thereafter, water was applied without tracers for an
additional 64 days. Both water movement and tracer movement
were monitored in the subsoil during infiltration and
redistribution. The experimental results indicate that water
and bromide moved fairly uniformly during infiltration and the
bromide moved ahead of the tritium due to anion exclusion
during redistribution. Comparisons between measurements and
predictions made with a two-dimensional model show qualitative
agreement for two of the three water content measurement
planes. Model predictions of tritium and bromide transport
were not as satisfactory. Measurements of both tritium and
bromide show localized areas of high relative concentrations
and a large downward motion of bromide relative to tritium
during redistribution. While the simple deterministic model
does show larger downward motions for bromide than for tritium
during redistribution, it does not predict the high
concentrations of solute observed during infiltration, nor can
it predict the heterogeneous behavior observed for tritium
during infiltration and for bromide during redistribution.
248 NAL Call. No.: QE581.F4 1991
Sediment-nutrient transport during severe storms.
Smith, S.J.; Sharpley, A.N.; Williams, J.R.; Berg, W.A.;
Coleman, G.A. Washington, D.C.? : Federal Energy Regulatory
Commission; 1991. Proceedings of the Fifth Federal Interagency
Sedimentation Conference, 1991 / edited by Shou-Shan Fan and
Yung-Huang Kuo ; sponsored by Subcommittee on Sedimentation of
the Interagency Advisory Committee on Water Data. p. PS/48-
PS/55; 1991. Includes references.
Language: English
Descriptors: Oklahoma; Texas; Runoff; Geological
sedimentation; Storms; Mathematical models; Prediction
249 NAL Call. No.: 56.9 SO3
Selenium mobility and distribution in irrigated and
nonirrigated alluvial soils.
Fio, J.L.; Fujii, R.; Deverel, S.J.
Madison, Wis. : The Society; 1991 Sep.
Soil Science Society of America journal v. 55 (5): p.
1313-1320; 1991 Sep. Includes references.
Language: English
Descriptors: California; Selenium; Salts in soil; Movement in
soil; Alluvial soils; Irrigated soils; Alkaline soils;
Solutes; Transport processes; Adsorption; Desorption;
Irrigation; Drainage; Irrigation water; Drainage water;
Dispersion; Mathematical models; Dissolving; Leaching;
Groundwater; Oxidation; Saturated conditions; Spatial
distribution; Soil depth; Gypsum; Hysteresis; Time lag;
Physicochemical properties
Abstract: Dissolution and leaching of soil salts by
irrigation water is a primary source of Se to shallow
groundwater in the western San Joaquin Valley, California. In
this study, the mobility and distribution of selenite and
selenate in soils with different irrigation and drainage
histories was evaluated using sorption experiments and an
advection-dispersion model. The sorption studies showed that
selenate (15-12 400 micrograms Se L-1) is not adsorbed to soil
whereas selenite (10-5000 micrograms Se L-1) is rapidly
adsorbed. The time lag between adsorption and desorption of
selenite is considerable, indicating a dependence of reaction
rate on reaction direction (hysteresis). Selenite adsorption
and desorption isotherms were different, and both were
described with the Freundlich equation. Model results and
chemical analyses of extracts from the soil samples showed
that selenite is resistant to leaching and therefore can
represent a potential long-term source of Se to groundwater.
In contrast, selenate behaves as a conservative constituent
under alkaline and oxidized conditions and is easily leached
from soil.
250 NAL Call. No.: 292.8 W295 A
semidiscrete model for water and solute movement in tile-
drained soils. 1. Governing equations and solution.
Kamra, S.K.; Singh, S.R.; Rao, K.V.G.K.; Van Genuchten, M.T.
Washington, D.C. : American Geophysical Union; 1991 Sep.
Water resources research v. 27 (9): p. 2439-2447; 1991 Sep.
Includes references.
Language: English
Descriptors: Drainage water; Solutes; Water flow; Movement in
soil; Transport processes; Aquifers; Tile drainage;
Prediction; Mathematical models
Abstract: A finite element model has been developed to
simulate solute transport in tile-drained soil-aquifer
systems. Water flow in the unsaturated zone and to drains in
the saturated zone was assumed to be at steady state. The
model considers the transport of nonreactive solutes, as well
as of reactive solutes whose behavior can be described by a
distribution coefficient. The exact-in-time numerical solution
yields explicit expressions for the concentration field at any
future point in time without having to compute concentrations
at intermediate times. The semidiscrete method involves the
determination of an eigensystem of eigenvalues and
eigenvectors of the coefficient matrix. The eigensystem may be
complex (i.e., it may have imaginary components) due to
asymmetry created by the convection term in the governing
convection-dispersion equation. The proposed approach
facilitates long-term predictions of concentrations in
drainage effluents and of salt distributions in soil and
groundwater. The accuracy of the model was verified by
comparing model results with those based on an analytical
solution for two-dimensional solute transport in groundwater.
251 NAL Call. No.: 292.8 W295 A
semidiscrete model for water and solute movement in tile-
drained soils. 2. Field validation and applications.
Kamra, S.K.; Singh, S.R.; Rao, K.V.G.K.; Van Genuchten, M.T.
Washington, D.C. : American Geophysical Union; 1991 Sep.
Water resources research v. 27 (9): p. 2449-2456; 1991 Sep.
Includes references.
Language: English
Descriptors: India; Drainage water; Solutes; Movement in soil;
Tile drainage; Subsurface drainage; Depth; Spacing; Soil
salinity; Water table; Effluents; Water quality; Aquifers;
Simulation; Prediction; Mathematical models
Abstract: An exact-in-time two-dimensional finite element
model for simulating convective-dispersive solute transport in
a tile-drained field is validated against observed data from a
subsurface drainage experiment. The model is capable of
predicting the long-term effects of different irrigation and
drainage practices on the salt distribution in an artificially
drained soil-aquifer system. The model was used to predict
transient changes in the salinity of the soil, the shallow
groundwater table, and the drain effluent. Results are also
presented on the effects of imposing alternative drain
spacing-depth combinations, initial groundwater salinities,
solute distribution coefficients, and different types of
layering of the aquifer, on the computed salinity
distributions in the unsaturated zone, the groundwater, and
the drain effluent.
252 NAL Call. No.: SB951.P47
Sensitivity analysis of a mathematical model for pesticide
leaching to groundwater.
Boesten, J.J.T.I.
Essex : Elsevier Applied Science Publishers; 1991.
Pesticide science v. 31 (3): p. 375-388; 1991. Includes
references.
Language: English
Descriptors: Netherlands; Pesticides; Groundwater; Leaching;
Mathematical models; Meteorological factors; Plants; Uptake;
Water pollution; Soil properties; Zea mays; Sandy soils
Abstract: The sensitivity of pesticide leaching to
pesticide/soil properties and to meteorological conditions was
assessed by calculations with an existing convection-
dispersion model. The model assumes equilibrium sorption
(Freundlich equation), first-order transformation kinetics and
passive plant uptake. The extent of pesticide leaching was
characterized by the percentage of the dose leached below 1 m
depth. The calculations were carried out for a humic sand soil
cropped with maize and exposed to Dutch weather conditions. In
general, the percentage leached was found to be very sensitive
to the sorption coefficient, the Freundlich exponent
(describing the curvature of the isotherm) and the
transformation rate. The percentage leached was moderately
sensitive to weather conditions (wet/dry years), long-term
sorption equilibration and the relationship between
transformation rate and temperature. Sensitivity to the extent
of plant uptake was only significant for pesticides with low
sorption coefficients. Sensitivity to soil hydraulic
properties was small. The effect of application in autumn
instead of in spring was found to be very large for non-
sorbing pesticides with short half-lives. The sensitivity to
spatial variability in sorption coefficient and transformation
rate was found to be substantial at low percentages leached.
253 NAL Call. No.: TD403.G7 A
simple analytical approach for predicting nitrate
concentrations in pumped ground water.
Lerner, D.N.; Papatolios, K.T.
Dublin, Ohio : Ground Water Pub. Co; 1993 May.
Ground water v. 31 (3): p. 37-375; 1993 May. Includes
references.
Language: English
Descriptors: England; Groundwater pollution; Pollutants;
Nitrates; Wells; Groundwater recharge; Concentration;
Prediction; Models; Aquifers
Abstract: A simple analytical expression is presented which
predicts how solute concentrations evolve with time in a
pumped well. The basic expression is for uniform recharge and
uniform concentration of a conservative solute (e.g. nitrate)
in the recharge. It shows that pumped concentrations are
independent of pumping rates. The expression can be developed
to allow for more complex patterns of recharge and solute
loading, and an example is given with three zones of recharge
and concentrations, induced river recharge, and a cross-
boundary inflow. Predictions are made for Edgmond Bridge, a
new pumping station which lies in a drift-filled valley in the
Triassic sandstone aquifer of Shropshire, UK. The model
predicts that concentrations of nitrate will stay below the
drinking water limit for 78 years, although this would be
substantially reduced if the aquifer were significantly
layered or if nitrate loads from agriculture increased.
Predictions were reevaluated after two years and found to be
consistent with observed patterns once actual, rather than
expected, conditions were incorporated in the model.
254 NAL Call. No.: 56.8 SO3 A
simple, inverse model for estimating nitrogen reaction rates
from soil column leaching experiments at steady water flow.
Yamaguchi, T.; Moldrup, P.; Rolston, D.E.; Hansen, J.A.
Baltimore, Md. : Williams & Wilkins; 1992 Dec.
Soil science v. 154 (6): p. 490-496; 1992 Dec. Includes
references.
Language: English
Descriptors: Soil analysis; Nitrification; Denitrification;
Nitrogen; Transport processes; Movement in soil; Soil water
movement; Leaching; Mathematical models
255 NAL Call. No.: S590.C63
Simple techniques for monitoring and predicting the movement
of chemicals in a field soil.
Phillips, I.R.
New York, N.Y. : Marcel Dekker; 1992.
Communications in soil science and plant analysis v. 23
(9/10): p. 965-980; 1992. Includes references.
Language: English
Descriptors: Leaching; Chemicals; Podzolic soils; Movement in
soil; Soil water movement; Exchangeable sodium; Sodium;
Calcium; Magnesium; Potassium; Bromide; Chloride; Soil
solution; Cation exchange; Anion exchange; Soil depth;
Mathematical models
256 NAL Call. No.: aZ5071.N3
Simulation models, GIS and nonpoint-source pollution--January
1988-June 1992. Holloway, D.; Makuch, J.
Beltsville, Md. : The Library; 1992 Sep.
Quick bibliography series - U.S. Department of Agriculture,
National Agricultural Library (U.S.). (92-69): 43 p.; 1992
Sep. Bibliography.
Language: English
Descriptors: Simulation models; Information systems;
Groundwater pollution; Agricultural chemicals; Bibliographies
257 NAL Call. No.: 292.8 W295
Simulation of a two-pollutant, two-season pollution offset
system for the Colorado River of Texas below Austin.
Letson, D.
Washington, D.C. : American Geophysical Union; 1992 May.
Water resources research v. 28 (5): p. 1311-1318; 1992 May.
Includes references.
Language: English
Descriptors: Texas; River water; Water pollution; Pollutants;
Water quality; Environmental impact; Seasonal variation;
Simulation models; Mathematical models
Abstract: A pollution offset system is a discharge permit
system in which transfers are made subject to a restriction
that no violations of water quality standards occur at any
location. Simulation of a pollution offset system with
seasonal variation and multiple pollutants allows for
comparison of the savings possible from these design features.
A simulation model (Qual-TX) developed by the Texas Water
Commission is applied to a case study region near Austin,
Texas, yielding impact coefficients for an economic
optimization model without investment whose least cost
solution represents the theoretical equilibrium of a pollution
offset system. The optimization model finds short-run savings
of 17.5% for a pollution offset system, as compared to a
command and control policy that would also achieve the
dissolved oxygen standard. Seasonalvariation in permit design
produces minimal effects; virtually all savings come from
allowing pollution offsets for the two different pollutants.
258 NAL Call. No.: TD426.J68
Simulation of nitrogen dynamics and leaching from arable
soils. Lotse, E.G.; Jabro, J.D.; Simmons, K.E.; Baker, D.E.
Amsterdam : Elsevier; 1992 Aug.
Journal of contaminant hydrology v. 10 (3): p. 183-196; 1992
Aug. Includes references.
Language: English
Descriptors: Pennsylvania; Arable soils; Soil chemistry;
Nitrogen balance; Nitrogen; Uptake; Nitrate nitrogen; Storage;
Profiles; Mineralization; Nitrification; Leaching; Simulation
models; Water pollution
259 NAL Call. No.: 56.8 SO3
Simulation of one-dimensional nitrate transport through soil
and concomitant nitrate diminution.
Sadeghi, A.M.; Kunishi, H.M.
Baltimore, Md. : Williams & Wilkins; 1991 Nov.
Soil science v. 152 (5): p. 333-339; 1991 Nov. Includes
references.
Language: English
Descriptors: Maryland; Sandy loam soils; Clay loam soils;
Nitrate; Ion transport; Movement in soil; Losses from soil
systems; Leaching; Laboratory methods; Undisturbed sampling;
Horizontal flow; Velocity; Dispersion; Sorption; Mathematical
models; Simulation; Nitrate nitrogen; Potassium nitrate;
Carbon; Phthalates; Nutrient sources; Hydrology; Watershed
management; Denitrification
260 NAL Call. No.: 292.9 AM34
Simulation of sediment and plant nutrient losses by the CREAMS
water quality model.
Yoon, K.S.; Yoo, K.H.; Soileau, J.M.; Touchton, J.T.
Bethesda, Md. : American Water Resources Association; 1992
Nov. Water resources bulletin v. 28 (6): p. 1013-1021; 1992
Nov. Includes references.
Language: English
Descriptors: Alabama; Gossypium hirsutum; Conservation
tillage; Tillage; Erosion; Runoff; Nitrogen; Phosphorus;
Losses from soil; Water quality; Water pollution; Catchment
hydrology; Simulation models; Prediction
Abstract: CREAMS was applied to a field-sized watershed
planted to cotton in the Limestone Valley region of northern
Alabama. The field was cultivated for three years with
conventional tillage (CvT) followed by three years or
conservation tillage (CsT). CREAMS is composed of three
components: hydrology, erosion, and chemistry. Surface runoff
and losses of sediment, N and P were simulated and results
were compared with the observed data from the watershed. Curve
numbers recommended in the CREAMS user's guide were not
adequate for the watershed conditions. The hydrology submodel
improved runoff simulation from CvT and CsT when field-data
based curve numbers were used. The erosion submodel
demonstrated that CsT reduced sediment loss more than CvT,
even though CsT had higher runoff than CvT. The nutrient
submodel based on the simulated runoff and sediment
underpredicted N loss for both CvT and CsT. This submodel,
however, accurately predicted P loss for CvT, but
underpredicted for CsT (50 percent lower than the observed).
The results of CREAMS simulation generally matched the
observed order of magnitude for higher runoff, lower sediment,
and higher N and P losses from CsT than from CvT.
261 NAL Call. No.: 292.8 J82
Simulation of water and chemicals in macropore soils. 2.
Application of linear filter theory.
Chen, C.; Wagenet, R.J.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Jan.
Journal of hydrology v. 130 (1/4): p. 127-149; 1992 Jan.
Includes references.
Language: English
Descriptors: Macropores; Macropore flow; Water flow; Hydraulic
conductivity; Soil water content; Transport processes; Linear
models; Simulation
Abstract: Description of flow in soils with macropores is
difficult, yet quite important in describing the dynamics of
field soils. Recognizing the two structural domains of the
macropore and matrix, and possible water-flow situations,
three flow regions have been suggested: matrix, macropore, and
transaction. The matrix and the macropore are the two domains,
and the transaction represents the exchange of water between
the matrix and the macropore. As a beginning point for the
description of such systems, linear filter theory is applied
to the Richards equation to obtain a general set of analytical
solutions for water and contaminant movement in unsaturated
soil in which there are no macropores. To develop these
solutions, it unique relationship between water flux (q) and
water content (0) is demonstrated by executing a numerical
simulation based on the Richards equation. By piece-wise curve
fitting of q(0), it is possible to establish and obtain a set
of equations which describe water flow and chemical movement
in soil, and which take the form of linear filter systems,
providing analytical solutions by convolution. A two-domain
approach applies equations for homogeneous soil to describe
the matrix domain, with the macropore domain described with
coefficients obtained by applying the Poiseuille and Chezy
equations. These equations are analytically solved in
correspondence with the three flow situations, resulting in a
model. LASOMS (linear analytical solutions of macropore
soils). Simulations, data and model comparisons of LASOMS have
shown the above solutions to be reasonable under several
conditions.
262 NAL Call. No.: 292.8 J82
Simulation of water and chemicals in macropore soils. 2.
Application of linear filter theory.
Chen, C.; Wagenet, R.J.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Jan.
Journal of hydrology v. 130 (1/4): p. 127-149; 1992 Jan.
Includes references.
Language: English
Descriptors: Macropores; Macropore flow; Water flow; Hydraulic
conductivity; Soil water content; Transport processes; Linear
models; Simulation
Abstract: Description of flow in soils with macropores is
difficult, yet quite important in describing the dynamics of
field soils. Recognizing the two structural domains of the
macropore and matrix, and possible water-flow situations,
three flow regions have been suggested: matrix, macropore, and
transaction. The matrix and the macropore are the two domains,
and the transaction represents the exchange of water between
the matrix and the macropore. As a beginning point for the
description of such systems, linear filter theory is applied
to the Richards equation to obtain a general set of analytical
solutions for water and contaminant movement in unsaturated
soil in which there are no macropores. To develop these
solutions, it unique relationship between water flux (q) and
water content (0) is demonstrated by executing a numerical
simulation based on the Richards equation. By piece-wise curve
fitting of q(0), it is possible to establish and obtain a set
of equations which describe water flow and chemical movement
in soil, and which take the form of linear filter systems,
providing analytical solutions by convolution. A two-domain
approach applies equations for homogeneous soil to describe
the matrix domain, with the macropore domain described with
coefficients obtained by applying the Poiseuille and Chezy
equations. These equations are analytically solved in
correspondence with the three flow situations, resulting in a
model. LASOMS (linear analytical solutions of macropore
soils). Simulations, data and model comparisons of LASOMS have
shown the above solutions to be reasonable under several
conditions.
263 NAL Call. No.: SB610.W39
Site-specific pesticide recommendations: the final step in
environmental impact prevention.
Hornsby, A.G.
Champaign, Ill. : The Society; 1992 Jul.
Weed technology : a journal of the Weed Science Society of
America v. 6 (3): p. 736-742; 1992 Jul. Paper presented at a
Symposium on the, "Role of Modeling in Regulatory Affairs," at
the Weed Science Society of America, February 4, 1991,
Louisville, Kentucky. Includes references.
Language: English
Descriptors: Florida; Pesticides; Environmental impact;
Leaching; Runoff; Toxicology; Soil properties; Water quality;
Water pollution; Decision making; Methodology; Simulation
models; Geographical information systems; Risk; Cooperative
extension service
264 NAL Call. No.: S623.O94 1992
Soil erosion and sediment yield modeling, simulation and
prediction. Overton, Donald E.,
Knoxville, TN : Stormwater Publications,; 1992.
197 p. : ill. (some col.) ; 23 cm. Includes bibliographical
references and indexes.
Language: English
Descriptors: Runoff; Soil erosion; Sediment transport
265 NAL Call. No.: 292.8 J82
Soil water content at R-5. 2. Impact of antecedent conditions
on rainfall-runoff simulations.
Loague, K.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Nov.
Journal of hydrology v. 139 (1/4): p. 253-261; 1992 Nov.
Includes references.
Language: English
Descriptors: Soil water content; Simulation models; Rain;
Runoff; Watersheds; Spatial variation; Topsoil; Subsoil; Soil
depth; Estimation
Abstract: In this paper, the second part of a two-part
series, the performance of a quasi-physically based rainfall-
runoff model (QPBRRM) is evaluated for a set of 39 events from
a small rangeland catchment (R-5) using a suite of alternative
antecedent soil water content estimates. The data set used to
glean antecedent conditions for the R-5 events, described in
the companion paper contains 22 848 observations of soil water
content made over a 4 year period. The performance of the
model is improved by using estimates of antecedent soil water
content that include consideration of spatial variability.
266 NAL Call. No.: 56.9 SO3
Soil water movement in response to temperature graidents:
experimental measurements and model evaluation.
Bach, L.B.
Madison, Wis. : The Society; 1992 Jan.
Soil Science Society of America journal v. 56 (1): p. 37-46;
1992 Jan. Includes references.
Language: English
Descriptors: Sandy loam soils; Soil water movement; Transport
processes; Soil water; Spatial distribution; Soil temperature;
Spatial variation; Laboratory methods; Measurement;
Comparisons; Simulation models; Mathematical models; Soil
water content; Heat flow; Thermal conductivity; Thermal
diffusivity; Water vapor; Matric potential; Soil water
retention
Abstract: Temperature gradients may have a significant effect
on soil water movement under certain conditions, but inclusion
of these effects adds complexity to the flow analysis. This
study was conducted to help clarify the significance of
nonisothermal water flow, and to examine theoretical and
numerical descriptions of the transport processes. At initial
water contents of 0.00, 0.049, 0.099, 0.151, and 0.282 m3 m-3
isothermal and nonisothermal laboratory experiments were
conducted to provide direct information on soil water movement
in response to temperature gradients. These data were used to
evaluate the numerical simulation model SPLaSHWaTr2, and to
examine calculation of the thermal conductivity, the thermal
vapor diffusivity, and the temperature coefficient of the
matric potential, based on modifications to a theory proposed
by Philip and de Vries in 1957. A statistically significant
effect of the temperature gradient was found at an initial
water content of 0.151 m3 m-3, which corresponds to a pressure
head of approximately -1.2 m of H2O. No effect of the
temperature gradient was found at initial water contents of
0.00, 0.049, 0.099, or 0.282 m3 m-3. Under isothermal
conditions, the model provided simulated water-content
profiles that were in good agreement with measured profiles.
Under nonisothermal conditions, profiles simulated by the
model were in poor agreement with the measured data, using the
original values of thermal conductivity, thermal vapor
diffusivity and the temperature coefficient of the matric
potential. Sensitivity analysis showed that thermal
conductivity and thermal vapor diffusivity had a negligible
influence on nonisothermal water movement. On the other hand,
the temperature coefficient of the matric potential had a
significant influence on nonisothermal water movement.
Adjusting the temperature coefficient of the matric potential
from the original value of -0.0068 K-1 to the value suggested
by Philip and de Vries, -0.00209 K-1, improved the a
267 NAL Call. No.: 56.9 SO3
Solute transport in a two-layer medium investigated with time
moments. Leij, F.J.; Dane, J.H.
Madison, Wis. : The Society; 1991 Nov.
Soil Science Society of America journal v. 55 (6): p.
1529-1535; 1991 Nov. Includes references.
Language: English
Descriptors: Layered soils; Transport processes; Solutes;
Movement in soil; Statistical methods; Mathematical models;
Soil boundaries; Interface; Soil water movement; Variance;
Models; Spreading
Abstract: The study of solute transport in porous media
requires knowledge of the transport parameters. These
transport parameters can be determined from data collected
during displacement experiments using a number of mathematical
procedures, among them the moment method. An advantage of this
method is that it can also be used to theoretically analyze,
and therefore enhance our understanding of, transport
problems. We present theoretical time moments as derived from
analytical solutions of the advection-dispersion equation in
the Laplace domain for a step- and pulse-type solute input
applied to a two-layer soil with steady flow transverse to
layering. These moments were used for investigating the mean
breakthrough time, u1, and variance, u2. It was shown that,
theoretically, more retardation and spreading occurs for a
third- than for a first-type boundary condition, but that the
presence of the interface, as such, does not affect spreading
for either boundary condition.
268 NAL Call. No.: 56.8 SO3
Solute transport through hard pans of paddy fields. 2. Cation
exchange processess.
Ishiguro, M.
Baltimore, Md. : Williams & Wilkins; 1992 Jan.
Soil science v. 153 (1): p. 42-47; 1992 Jan. Includes
references.
Language: English
Descriptors: Paddy soils; Compact soils; Pans; Disturbed
soils; Solutes; Transport processes; Exchangeable cations;
Movement in soil; Calcium ions; Strontium; Bromide; Simulation
models; Laboratory methods; Mathematical models; Cation
exchange; Cation exchange capacity; Adsorption; Equilibrium;
Diffusivity; Roots; Pores; Pore volume
269 NAL Call. No.: 56.8 SO3
Solute transport through hard pans of paddy fields. I. Effect
of vertical tubular pores made by rice roots on solute
transport.
Ishiguro, M.
Baltimore, Md. : Williams & Wilkins; 1991 Dec.
Soil science v. 152 (6): p. 432-439; 1991 Dec. Includes
references.
Language: English
Descriptors: Oryza sativa; Paddy soils; Gley soils; Andosols;
Lowland areas; Subsoil; Soil compaction; Transport processes;
Bromine; Movement in soil; Macropores; Roots; Simulation;
Measurement; Calculation; Mathematical models; Convection;
Diffusion; Velocity; Pore volume
270 NAL Call. No.: QH540.J6
Sorptive reversibility of atrazine and metolachlor residues in
field soil samples.
Pignatello, J.J.; Huang, L.Q.
Madison, Wis. : American Society of Agronomy; 1991 Jan.
Journal of environmental quality v. 20 (1): p. 222-228; 1991
Jan. Includes references.
Language: English
Descriptors: Atrazine; Metolachlor; Herbicide residues;
Measurement; Samples; Soil pollution; Sorption; Theory;
Transport processes; Leaching; Mathematical models
Abstract: Predictions of the fate and transport of organic
compounds in soils depend on sound sorption models. The
impacts of slowly reversible (nonequilibrium) sorption on
compound fate are not well quantified. Soil samples containing
residues of the herbicides atrazine (2-chloro-4-ethylamino-6-
isopropyl-1,3,5-triazine) and metolachlor (2-chloro-N-[2-
ethyl-5-methylphenyl]-N-[2-methoxy-1-methylethyl]-acetamide)
were collected from fields 2 to 15 mo after their last
application to assess the sorptive reversibility of these
residues. The apparent sorption constant of the native
herbicide, Kapp was determined from the sorbed and solution
concentrations after suspension of the sample in water for 24
h. The "equilibrium" sorption constant, Kd, was determined in
the same samples from 24 h sorption isotherms of freshly added
herbicide, taking into account the fraction of labile native
herbicide (fL). The ratio Kapp/Kd varied from 2.3 to 42 and
was directly related to the "age" of the residue (i.e, time
between sampling and last application). The value of fL ranged
from 0.056 to 0.60 and was inversely related to the age of the
residue. The results indicate that contaminated samples
collected from the field can contain a large fraction of
contaminant in a slowly reversible sorbed state, and that this
fraction increase with time.
271 NAL Call. No.: 501 L84B
Spatio-temporal pattern formation in nonlinear non-equilibrium
plankton dynamics.
Malchow, H.
London : The Society; 1993 Feb22.
Proceedings of the Royal Society of London : Series B :
Biological sciences v. 251 (1331): p. 103-109; 1993 Feb22.
Includes references.
Language: English
Descriptors: Algae; Phytoplankton; Zooplankton; Aquatic
communities; Indicator plants; Indicator species; Spatial
distribution; Temporal variation; Water quality; Mathematical
models
272 NAL Call. No.: 56.8 J822
Statewide GIS-based ranking of watersheds for agricultural
pollution prevention.
Hamlett, J.M.; Miller, D.A.; Day, R.L.; Peterson, G.W.;
Baumer, G.M.; Russo, J.
Ankeny, Iowa : Soil and Water Conservation Society of America;
1992 Sep. Journal of soil and water conservation v. 47 (5): p.
399-404; 1992 Sep. Includes references.
Language: English
Descriptors: Pollution; Watersheds; Ranking; Computer
techniques; Models; Databases; Geography
273 NAL Call. No.: 292.8 W295
Statistical analysis of spatial variability in unsaturated
flow parameters. Russo, D.; Bouton, M.
Washington, D.C. : American Geophysical Union; 1992 Jul.
Water resources research v. 28 (7): p. 1911-1925; 1992 Jul.
Includes references.
Language: English
Descriptors: Sandy loam soils; Unsaturated flow; Leaching;
Soil properties; Hydraulic conductivity; Soil water retention;
Spatial variation; Stochastic models; Statistical analysis;
Autocorrelation; Prediction
Abstract: Core scale estimates of soil parameters of the
Gardner-Russo and van Genuchten models of the hydraulic
conductivity and water retention functions were obtained for
417 undisturbed soil cores taken from a wall of a trench (20 m
long, 2.5 m deep), using a procedure based on inverse problem
methodology. These estimates were used to evaluate the first
two statistical moments of the underlying random space
functions (RSFs), using the restricted maximum likelihood
estimation procedure, coupled with the weighted least squares
procedure, to estimate parameters of models of the covariance
and the drift functions of the pertinent RSFs. The fitted
models were used to evaluate the mean and covariance functions
of the hydraulic conductivity and water retention functions
for given water saturations. Covariance functions of log-
saturated conductivity (log Ks) and the "shape" parameters of
the Gardner-Russo and van Genuchten models exhibited
statistical anisotropy characterized by aspect ratios that
vary between 3 to 4. Correlation scales of log Ks were larger
than those of the "shape" parameters. Consequently, the
product of the variance of log unsaturated conductivity and
its correlation scale remained essentially invariant for a
considerable range of water saturation. The implications of
these results regarding stochastic modeling of transport in
heterogeneous porous formations and possible applications of
the results of this study are discussed briefly.
274 NAL Call. No.: TD426.J68
Statistical and graphical methods for evaluating solute
transport models: Overview and application.
Loague, K.; Green, R.E.
Amsterdam : Elsevier; 1991 Jan.
Journal of contaminant hydrology v. 7 (1/2): p. 51-73. maps;
1991 Jan. Includes references.
Language: English
Descriptors: Groundwater pollution; Pollutants; Persistence;
Prediction; Mathematical models; Pesticides; Leaching
275 NAL Call. No.: 292.8 W295
Stochastic analysis of simulated vadose zone solute transport
in a vertical cross section of heterogeneous soil during
nonsteady water flow. Russo, D.
Washington, D.C. : American Geophysical Union; 1991 Mar.
Water resources research v. 27 (3): p. 267-283; 1991 Mar.
Includes references.
Language: English
Descriptors: Soil water; Solutes; Water flow; Unsaturated
flow; Horizontal flow; Vertical movement; Transport processes;
Hydraulic conductivity; Spatial variation; Stochastic models;
Simulation
Abstract: The problem of transport of a conservative
nonreactive solute in a vertical cross section of a
hypothetical partially saturated, scale-heterogeneous soil
under transient water flow was analyzed here. It was assumed
that locally the water flow and the solute transport can be
described by the Richards' equation and by the one-component
convection dispersion equation, respectively. The simulated
water content and the solute concentration distributions in
the vertical cross section of the soil at different elapsed
times were quantified in terms of space averages and two-point
autocorrelation functions. The time evolution of the solute
plume was quantified in terms of its first two normalized
spatial moments, from which the time dependence of the
longitudinal and the transverse components of the solute
velocity vector, and the spatial covariance tensor, were
estimated. The results of this study, which are relevant to
solute transport at the local or the plume scale, demonstrated
the considerable variability in the solute concentration in
space and time, due to the complex heterogeneity of the soil
hydraulic properties in both the vertical and the horizontal
directions. Consequently, the movement of the solute plume was
characterized by a compression-expansion phenomenon,
attributed to the decrease in the effective solute velocity
through the zones of relatively fine-textured soil material.
It was concluded that existing stochastic vadose zone
transport models may be applicable to shallow depths but may
fail to describe the actual spread of a solute plume when the
transport takes place at relatively large depths, mainly
because of the neglect of the significant vertical
heterogeneity in the soil hydraulic properties.
276 NAL Call. No.: 292.8 J82
Stochastic modelling of solute flux in the unsaturated zone at
the field scale.
Destouni, G.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1993 Mar01.
Journal of hydrology v. 143 (1/2): p. 46-61; 1993 Mar01.
Special Issue: Modelling Flow and Transport in the Unsaturated
Zone: Scale Problems and Spatial Variability. Includes
references.
Language: English
Descriptors: Solutes; Unsaturated flow; Transport processes;
Spatial variation; Saturated hydraulic conductivity; Pore size
distribution; Mathematical models
Abstract: Spatial variability in both the saturated hydraulic
conductivity and the pore-size distribution is incorporated in
a stochastic model of field-scale solute transport through the
unsaturated zone. The transport model considered is based on a
Lagrangian framework, in which the expected field-scale solute
flux and the associated uncertainty in predictions are defined
from distributions of solute travel time. Expressions for such
travel time distributions are derived from statistical
information on measurable soil hydraulic properties and are
used to analyze the statistics of the field-scale solute flux
in heterogeneous soil. The spatial variability in the
saturated hydraulic conductivity and in the pore-size
distribution has a similar effect on the prediction
uncertainty, quantified by the variance of the solute flux, as
on the expected breakthrough curve. The effect on the relative
prediction uncertainty, quantified by the coefficient of
variation for the solute flux, is therefore small. Both the
solute flux variance and the coefficient of variation decrease
rapidly with increasing size of the input domain and are
considerably smaller for a planar source than for a linear
one.
277 NAL Call. No.: QD1.A45
Study design to investigate and simulate agrochemical movement
and fate in groundwater recharge.
Asmussen, L.E.; Smith, C.N.
Washington, D.C. : The Society; 1991.
ACS Symposium series - American Chemical Society (465): p.
150-164; 1991. In the series analytic: Groundwater residue
sampling design / edited by R.G. Nash and A.R. Leslie.
Includes references.
Language: English
Descriptors: Georgia; Groundwater; Agricultural chemicals;
Water quality; Water pollution; Sampling; Mathematical models
Abstract: The vulnerability of aquifers to contamination by
agrochemicals is relatively high in the southeastern Coastal
Plain. Transport and fate of agrochemicals in either the root,
unsaturated, or saturated zones can be simulated by existing
mathematical models. However, a linked mathematical model is
needed to simulate the movement and degradation from the point
of application through the unsaturated zone, and into
groundwater. The United States Geological Survey and
Agricultural Research Service initiated a cooperative
investigation in 1986. In 1988, the United States
Environmental Protection Agency joined the research
investigation. These agencies are sharing technical expertise
and resources to develop an understanding of physical,
chemical, and biological processes and to evaluate their
spatial and temporal variability; and to develop and validate
linked model(s) that would describe chemical transport and
fate. Study sites have been selected in the Fall Line Hills
district of the Coastal Plain province. The Claiborne aquifer
recharge area is located in this district near Plains,
Georgia. Instrumentation to measure water and chemical
transport has been installed.
278 NAL Call. No.: TD899.P3N34 no.618
Supplemental user's guide for applying the WASP4 model
program. National Council of the Paper Industry for Air and
Stream Improvement (U.S.) New York, N.Y. : National Council of
the Paper Industry for Air and Stream Improvement,; 1991.
2 v. : ill. ; 28 cm. (Technical bulletin (National Council of
the Paper Industry for Air and Stream Improvement (U.S.) :
1981) ; no. 618.). Cover title. "September 1991"--Cover.
Includes bibliographical references.
Language: English
Descriptors: Water quality; Information storage and retrieval
systems
279 NAL Call. No.: 292.8 J82
Surface runoff and soil water percolation as affected by snow
and soil frost. Johnsson, H.; Lundin, L.C.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1991 Jan.
Journal of hydrology v. 122 (1/4): p. 141-159; 1991 Jan.
Includes references.
Language: English
Descriptors: Arable soils; Frost; Snow; Spatial variation;
Infiltration; Water flow; Drainage; Soil water content;
Unfrozen water; Soil temperature; Frozen conditions; Soil
depth; Soil pore system; Simulation models
Abstract: A coupled soil water and heat model was used to
study the influence of soil frost and snow on infiltration and
drainage flow in an agricultural field in central Sweden. An
analogy between freezing/thawing and drying/wetting was
assumed for the soil frost submodel. Model simulations were
evaluated against measurements of total soil water content,
unfrozen water content, soil temperature and drainage water-
flow. The influences of soil frost and spatial variation in
snow cover were studied by simulation of possible extreme
situations in the field. The model accurately described the
dynamics of soil temperature and water contents; however,
infiltration and field drainage flow were considerably
underestimated and delayed by about three weeks under frozen
conditions. A model simulation, discounting the effects of
soil frost, overestimated the drain response. An attempt at
simulating the field variation in snow cover by assuming
possible 'sink points' for snowmelt, explained part of the
deviations between simulated and measured drain flows. A basis
for a new model formulation of the infiltration and
percolation processes in frozen soil is proposed in which two
water-flow domains are assumed, one low-flow domain in the
fine pores. smaller than those filled with ice, and one high-
flow domain in the large air-filled pores. This allows the
simulation of rapid infiltration in large ice-free pores and
drainage flow under frozen conditions as well as the resulting
redistribution of ice from smaller to larger pores.
280 NAL Call. No.: 292.8 W295
Surface runoff contamination by chemicals initially
incorporated below the soil surface.
Wallach, R.; Shabtai, R.
Washington, D.C. : American Geophysical Union; 1993 Mar.
Water resources research v. 29 (3): p. 697-704; 1993 Mar.
Includes references.
Language: English
Descriptors: Runoff; Overland flow; Agricultural chemicals;
Contamination; Clay soils; Silt loam soils; Incorporation;
Soil depth; Mathematical models; Prediction
Abstract: One method of reducing the contamination of
overland flow by soil chemicals (e.g., nutrients, pesticides)
is to reduce their concentration at the immediate soil
surface. This can be done by incorporating the chemicals at
lower depths, by either tilling the soil or by irrigating
shortly after chemical application. A mathematical model
designed to predict the runoff concentration of chemicals
initially, located at different depths below the soil surface
is presented. The model accounts for transient water
infiltration and convective-dispersive solute transport in the
soil, and also considers rate-limited mass transfer through a
laminar boundary layer at the soil surface/runoff water
interface. Sorption-desorption interactions between soil and
chemicals are assumed to be subject to linear isotherms or to
first-order kinetics. The dissolved chemical concentrations at
the soil surface and in the surface runoff were simulated for
coarse and fine soils at different antecedent soil moistures
and rainfall intensities. The simulation indicated that the
initial depth of chemical incorporation below the soil surface
is negatively correlated to the dissolved chemical
concentration at the soil surface and in runoff water. A basic
and characteristic difference between the chemical whose
retention by the soil solids is expressed by an equilibrium
model and the one whose retention is expressed by a kinetic
model is soil surface concentration during water and chemical
redistribution following the termination of rainfall and
runoff. Contrary, to the instantaneous equilibrium-type
chemicals, the dissolved concentration of the kinetic-type
chemicals increases sharply to its final value. For the
coarser soil with higher saturated hydraulic conductivity, the
relative chemical concentrations in surface runoff are lower
than for the finer soil, when similar values of initial
pressure head psi (0) and rainfall intensities (three times
the saturated hydraulic conductivity of each soil) are
281 NAL Call. No.: 292.8 W295
Surface runoff contamination by soil chemicals: simulations
for equilibrium and first-order kinetics.
Wallach, R.; Shabtai, R.
Washington, D.C. : American Geophysical Union; 1992 Jan.
Water resources research v. 28 (1): p. 167-173; 1992 Jan.
Includes references.
Language: English
Descriptors: Agricultural chemicals; Solutes; Runoff; Overland
flow; Contamination; Soil water content; Rain; Sloping land;
Infiltration; Transport processes; Sorption; Desorption;
Kinetics; Prediction; Mathematical models
Abstract: A model was developed to predict the potential
contamination of overland flow by chemicals removed from soil
water by rainfall on sloping soil. The model accounts for
transient water infiltration and convective-dispersive solute
transport in the soil and also considers rate-limited mass
transfer through a laminar boundary layer at the soil
surface/runoff water interface. Sorption-desorption
interactions between soil and chemicals are assumed to be
subject to linear and nonlinear isotherms or to first-order
kinetics. The dissolved-chemical concentrations at the soil
surface and in the surface runoff were determined for
different antecedent soil moistures and rainfall intensities.
These concentrations are lower when the antecedent moisture is
low because the time of ponding for drier soil is longer and
because during that period soil solutes are displaced by
greater volumes of infiltrating water. For a specified initial
soil water content, higher rainfall rates cause higher
dissolved-chemical concentrations at the soil surface. The
degree of nonlinearity of the equilibrium isotherm greatly
affects the transient dissolved-chemical concentrations and
the linear isotherm cannot always be used as an alternative.
These concentrations are also greatly affected by the value of
the kinetics rate coefficient. In the first-order kinetics
model there is a recovery of the dissolved-chemical
concentration at the soil surface during the period between
rainstorms. As a result, the initial concentration at the soil
surface for the subsequent rainstorm is higher than that
expected when equilibrium is assumed.
282 NAL Call. No.: Q320.B56
Surface transport of microorganisms by water.
Moore, J.A.
Stoneham, Mass. : Butterworth Publishers; 1991.
Biotechnology (15): p. 41-55; 1991. In the Series Analytic:
Assessing Ecological Risks of Biotechnology / edited by Lev R.
Ginzburg. Includes references.
Language: English
Descriptors: Contaminants; Microbial contamination; Movement;
Water transport; Runoff water; Models
283 NAL Call. No.: TD420.A1P7
System modeling approach for solute transport through upper
soils. Liu, C.C.K.; Feng, J.S.; Chen, W.
Oxford : Pergamon Press; 1991.
Water science and technology : a journal of the International
Association on Water Pollution Research and Control v. 24 (6):
p. 67-72; 1991. In the series analytic: Watermatex '91 /
edited by T.O. Barnwell, P.J. Ossenbruggen and M.B. Beck.
Proceedings of the "Second International Conference on Systems
Analysis in Water Quality Management," June 3-6, 1991, Durham,
New Hampshire. Includes references.
Language: English
Descriptors: Hawaii; Soil; Surface layers; Solutes; Movement
in soil; Agricultural chemicals; Groundwater pollution;
Physical models; Simulation models; Systems approach; Case
studies; Fenamiphos; Transport processes
284 NAL Call. No.: S671.A66
Targeting animal waste pollution potential using a geographic
information system.
Heatwole, C.D.; Shanholtz, V.O.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 Nov. Applied engineering in agriculture v. 7
(6): p. 692-698; 1991 Nov. Includes references.
Language: English
Descriptors: Virginia; Water pollution; Animal wastes; Site
factors; Geography; Environmental impact; Models; Screening;
Indexes; Ranking
Abstract: Data on livestock operations were added as a data
layer and corresponding attribute table to the Virginia
Geographic Information System (VirGIS) for seven counties in
Virginia. A simple model calculates an animal waste pollution
index (AWPI) which rates each site based on waste load, slope,
and distance-to-stream. These factors are considered both for
the facility as well as for the potential land application
area surrounding the farm site. The geographic information
system (GIS) database and model were used to produce maps and
corresponding tables of facilities ranked by AWPI. Outputs
were used as a screening tool to identify high-risk sites.
Model evaluation based on 1253 farm sites in Rockingham County
and 311 sites in Augusta County indicate a balance in site
versus application area contribution to AWPI. For these two
counties, the distribution of AWPI ratings is conducive to
effective targeting. No relationship between animal type and
AWPI was evident.
285 NAL Call. No.: 56.8 J822
Teaching land management with a microcomputer-based model.
Ross, D.; Nash, T.; Harbor, J.
Ankeny, Iowa : Soil and Water Conservation Society of America;
1992 May. Journal of soil and water conservation v. 47 (3): p.
226-230; 1992 May. Includes references.
Language: English
Descriptors: Land management; Soil conservation; Teaching
methods; Land use; Computer assisted instruction;
Microcomputers; Computer simulation; Simulation models;
Universal soil loss equation; Water erosion; Runoff;
Measurement; Erosion control; Sediment; Geological
sedimentation; Gully erosion; Land types
286 NAL Call. No.: GB701.W375 no.91-4068
Techniques for estimating selected parameters of the U.S.
Geological Survey's Precipitation-Runoff Modeling System in
eastern Montana and northeastern Wyoming.
Cary, Lawrence E.
United States, Bureau of Land Management, Geological Survey
(U.S.) Helena, Mont. : U.S. Dept. of the Interior, U.S.
Geological Survey ; Denver, CO : Books and Open-File Reports
Section [distributor,; 1991; I 19.42/4:91-4068.
iv, 39 p. : ill., maps ; 28 cm. (Water-resources
investigations report ; 91-4068). Shipping list no.: 92-047-
P. November 1991. Includes bibliographical references (p.
36-39).
Language: English; English
Descriptors: Precipitation (Meteorology); Hydrologic cycle;
Watersheds
287 NAL Call. No.: 56.8 J822
Terrain analysis: integration into the agricultural nonpoint
source (AGNPS) pollution model.
Panuska, J.C.; Moore, I.D.; Kramer, L.A.
Ankeny, Iowa : Soil and Water Conservation Society of America;
1991 Jan. Journal of soil and water conservation v. 46 (1): p.
59-64; 1991 Jan. Includes references.
Language: English
Descriptors: Terrain; Pollution; Water quality; Erosion;
Computer simulation
288 NAL Call. No.: 56.9 SO3 A
test of the local equilibrium assumption for adsorption and
transport of picloram.
Gaber, H.M.; Comfort, S.D.; Inskeep, W.P.; El-Attar, H.A.
Madison, Wis. : The Society; 1992 Sep.
Soil Science Society of America journal v. 56 (5): p.
1392-1400; 1992 Sep. Includes references.
Language: English
Descriptors: Silt loam soils; Picloram; Movement in soil;
Equilibrium; Transport processes; Adsorption; Sorption
isotherms; Soil water; Soil pore system; Soil water movement;
Velocity; Kinetics; Mathematical models; Bromine
Abstract: The inability of transport models that use a local
equilibrium assumption (LEA) to describe contaminant transport
under certain conditions has led to the development of various
criteria for assessing LEA applicability. Our objectives were
to determine the influence of pore water velocity on the
adsorption and transport of picloram
(4-amino-3,5,6-trichloropicolinic acid) and evaluate the use
of dimensionless Damkohler numbers for identifying
experimental conditions conducive to nonequilibrium transport.
Three sets of transport experiments were conducted to study
the movement of Br- and picloram through an Amsterdam silt
loam soil (fine-silty, mixed Typic Haploboroll). Experiments
were performed by displacing a 100-mL Br-14C-labeled picloram
pulse through disturbed soil columns (5.1-cm diam, 30-cm
length) at pore water velocities of 4.1, 40.6, and 200.1 cm
d-1. The kinetic parameters of picloram adsorption and
desorption were obtained independently. Results indicated that
Br- breakthrough curves (BTCs) were symmetrical at each pore
water velocity. In contrast, picloram BTCs were shifted to the
left on a pore-volume basis and demonstrated increased tailing
with increasing pore water velocities. The use of LEA with a
batch-determined distribution coefficient (Kd) in the
convection-dispersion equation adequately described picloram
BTCs at the 4.1 cm d-1 pore water velocity, but overestimated
the elution time at faster pore water velocities. These
observations were consistent with conclusions derived from
criteria used to assess LEA applicability and indicate that
knowledge of reaction kinetics and convective velocities can
be easily used to identity conditions conducive to
nonequilibrium transport.
289 NAL Call. No.: QH540.J6
Tests of the pesticide root zone model and the aggregate model
for transport and transformation of aldicarb, metolachlor, and
bromide. Parrish, R.S.; Smith, C.N.; Fong, F.K.
Madison, Wis. : American Society of Agronomy; 1992 Oct.
Journal of environmental quality v. 21 (4): p. 685-697; 1992
Oct. Includes references.
Language: English
Descriptors: Aldicarb; Metolachlor; Bromide; Tracers;
Profiles; Leaching; Vertical movement; Pesticide residues;
Soil water movement; Sorption; Soil depth; Velocity;
Dispersion; Mathematical models; Simulation models; Prediction
Abstract: Mathematical models are widely used to predict
leaching of pesticides and nutrients in agricultural systems.
This work was conducted to investigate the predictive
capability of the Pesticide Root Zone Model (PRZM) and the
Aggregate model (AGGR) for the pesticides aldicarb [2-
methyl-2-(methylthio)propionaldehyde O-
(methylcarbamoyl)oxime], metolachlor [2-chloro-N-(2-ethyl-6-
methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide], and for
a bromide tracer. Model predictions were compared with data
collected during 1984 to 1987 in the Dougherty Plain area of
southwestern Georgia. Field data were used to estimate mean
concentrations of pesticide and bromide residues in the soil
profile on various dates after application in each of four
growing seasons. Both models tended to predict rates of
movement of bromide tracer compounds in excess of that
observed. For metolachlor, a pesticide with a sorption-
partition coefficient that is higher than for other compounds
in the study, both models provided reasonably accurate
predictions within the upper 30-cm zone. For the pesticide
aldicarb, results were more variable. The results suggest that
the hydrologic components of both models are more accurate for
the upper zones, but they are imprecise in deeper zones,
underpredicting vertical dispersion and overpredicting
transport velocity.
290 NAL Call. No.: SB249.N6
Theoretical background and validation of CPM, A new cotton
simulation model. Sequeira, R.A.; Olson, R.L.
Memphis, Tenn. : National Cotton Council of America; 1993.
Proceedings - Beltwide Cotton Conferences. p. 543-549; 1993.
Meeting held January 10-14, 1993, New Orleans, Louisiana.
Includes references.
Language: English
Descriptors: Cotton; Simulation models; Validity; Theory
291 NAL Call. No.: 292.8 W295
Theoretical study of the significance of nonequilibrium
dissolution of nonaqueous phase liquids in subsurface systems.
Powers, S.E.; Loureiro, C.O.; Abriola, L.M.; Weber, W.J. Jr
Washington, D.C. : American Geophysical Union; 1991 Apr.
Water resources research v. 27 (4): p. 463-477; 1991 Apr.
Includes references.
Language: English
Descriptors: Groundwater pollution; Soil pollution; Subsurface
layers; Aquifers; Pollutants; Mass transfer; Movement in soil;
Mathematical models
Abstract: The objective of this work is to assess the
potential significance of deviations from local equilibrium
for the exchange of mass between residual nonaqueous phase
liquids and the aqueous phase in the saturated groundwater
zone. A one-dimensional convection-dispersion mass balance
equation incorporating a first-order interphase mass transfer
rate relationship and temporal changes in blob configuration
is used to model this system. Analytical and numerical methods
are employed to examine the steady state and transient
behavior of the system under a variety of hypothetical aquifer
conditions and pumping remediation schemes. Sensitivity of the
model to several parameters including mass transfer
coefficient, blob size and shape, and Darcy velocity is
explored. Results of the theoretical assessment indicate that
nonequilibrium effects could play a significant role in some
contamination scenarios, primarily for large blob sizes and
relatively high velocities. Design of soil flushing techniques
will be impacted by these conclusions. Uncertainty in several
parameter values used in this analysis indicate the need for
further experimental investigation of this process.
292 NAL Call. No.: HC110.W43T48 1993
Theory, modeling, and experience in the management of
nonpoint-source pollution.
Russell, Clifford S.; Shogren, Jason F.
Boston : Kluwer Academic Publishers,; 1993.
xvii, 345 p. : ill., maps ; 24 cm. (Natural resource
management and policy). Papers presented at a workshop
sponsored by the Association of Environmental and Resource
Economists and held at the University of Kentucky, Lexington,
KY, in June 1991. Includes bibliographical references.
Language: English; English
Descriptors: Water; Agricultural pollution; Water quality
management
293 NAL Call. No.: 292.8 W295 A
three-dimensional field study of solute transport through
unsaturated, layered, porous media. 2. Characterization of
vertical dispersion. Ellsworth, T.R.; Jury, W.A.
Washington, D.C. : American Geophysical Union; 1991 May.
Water resources research v. 27 (5): p. 967-981; 1991 May.
Includes references.
Language: English
Descriptors: Transport processes; Vertical movement;
Dispersion; Solutes; Soil types; Prediction; Mathematical
models; Transformation
Abstract: Solute plumes were created in an unsaturated field
soil with either flux application or by leaching an initial
resident distribution (see Ellsworth et al., this issue). The
spatial variance of the plumes initially increased with time
between the soil surface and a depth of 2.5 m, within which
the soil was a nearly structureless loamy sand. Below this
depth, the plumes were observed to compress in the vertical
direction as they moved into, and through, a region of
subangular blocky structure and loam texture (between 2.5 and
4.0 m depth). As the solute moved below the layer of fine
texture, the plume variance again increased with time. Using a
transformed advection-dispersion equation description, two
constant, field-averaged transport coefficients, V and D zz,
were determined in a scaled coordinate system from the moment
equations. These two constant parameters were then used to
predict the observed local, or plot scale, transport. Results
indicate that the two constant parameters describe transport
reasonably well at each plot site and over all sampling
depths.
294 NAL Call. No.: 292.8 W295 A
three-dimensional field study of solute transport through
unsaturated, layered, porous media. I. Methodology, mass
recovery, and mean transport. Ellsworth, T.R.; Jury, W.A.;
Ernst, F.F.; Shouse, P.J.
Washington, D.C. : American Geophysical Union; 1991 May.
Water resources research v. 27 (5): p. 951-965; 1991 May.
Includes references.
Language: English
Descriptors: California; Transport processes; Solutes; Soil
types; Physicochemical properties; Prediction; Mathematical
models
Abstract: A field experiment is reported which monitored the
three-dimensional movement of cubic solute plumes through an
unsaturated, loamy sand soil. The plumes were created with one
of two methods, a two-dimensional flux application and an
initial resident distribution. Soil coring was used to sample
resident concentrations for the three solutes studied. The
data were analyzed using the method of moments. In addition to
the solute transport experiments, a detailed set of physical
properties of the field was obtained by excavating three pits
to a depth of 5.0 m and also by taking soil cores throughout
the study area. This paper explains the experimental
methodology, summarizes the relevant site characteristics, and
describes the observed transport based on the zeroth and first
order spatial moments. Mass balance varied between 78 and
138%. The field-averaged gravimetric water content and dry
bulk density were used to accurately predict the mean vertical
plume displacements. The plumes spread relatively little in
the horizontal direction.
295 NAL Call. No.: TD420.A1P7
Trace metal soil quality criteria to protect groundwater. Lee,
J.; Chen, B.; Allen, H.E.; Huang, C.P.; Sparks, D.L.; Sanders,
P. Oxford : Pergamon Press; 1992.
Water science and technology : a journal of the International
Association on Water Pollution Research and Control v. 26
(9/11): p. 2327-2329; 1992. In the series analytic: Water
Quality International '92. Part 5 / edited by M. Suzuki,
et.al. Proceedings of the Sixteenth Biennial Conference of the
International Association on Water Pollution Research and
Control held May 24-30, 1992, Washington, D.C.
Language: English
Descriptors: New Jersey; Soil pollution; Pollutants;
Standards; Metals; Groundwater pollution; Soil; Adsorption;
Soil ph; Mathematical models
296 NAL Call. No.: TD403.G7
Tracer test evaluation of a drainage ditch capture zone.
Chambers, L.W.; Bahr, J.M.
Dublin, Ohio : Ground Water Pub. Co; 1992 Sep.
Ground water v. 30 (5): p. 667-675; 1992 Sep. Includes
references.
Language: English
Descriptors: Wisconsin; Groundwater pollution; Agricultural
chemicals; Spread; Prevention; Drainage; Ditches; Tracers;
Iodide; Bromide; Tests; Prediction; Capacity; Analytical
methods; Models; Movement in soil
297 NAL Call. No.: TD403.G7
Transient and steady-state solute transport through a large
unsaturated soil column.
Porro, I.; Wierenga, P.J.
Dublin, Ohio : Ground Water Pub. Co; 1993 Mar.
Ground water v. 31 (2): p. 193-200; 1993 Mar. Includes
references.
Language: English
Descriptors: Soil pollution; Groundwater pollution;
Pollutants; Solutes; Movement in soil; Transient flow; Steady
flow; Unsaturated flow; Prediction; Models
Abstract: The use of steady-state models can sometimes reduce
the computational resources and input data required for
solution of transient transport problems. A large column
experiment was performed to test whether solute transport
parameters determined from a steady flow experiment may be
used in transient, unsaturated flow and transport model
predictions. Tritiated water and bromide were applied at a
steady rate to the top of a 0.95 m diameter by 6 m deep soil
column containing unsaturated soil. After 10 days, tracers
were eliminated from the irrigation water. When the soil
moisture content within the column ceased to change, another
10-day pulse of tritiated water and bromide was applied,
followed by water without tracers. Transport model parameters
were determined through optimization, using breakthrough
curves observed at various depths. The tritiated water and
bromide pulses lagged behind the wetting front during
infiltration into the relatively dry soil. The bromide pulse
moved 17-20% faster than the tritiated water pulse, because of
anion exclusion. Breakthrough curves for the transient and
steady-state experiments were similar. Because the solute
fronts lagged significantly behind the moisture fronts,
steady-state transport parameters, when used in a fully
transient numerical model, fairly described the transport
under transient conditions.
298 NAL Call. No.: 56.9 SO3
Transport in a horizontal flow chamber.
Sadeghi, A.M.; Starr, J.L.
Madison, Wis. : The Society; 1992 Mar.
Soil Science Society of America journal v. 56 (2): p. 600-603;
1992 Mar. Includes references.
Language: English
Descriptors: Groundwater flow; Horizontal flow; Transport
processes; Laboratory methods; Simulation models; Soil water;
Soil pore system; Velocity; Hydrodynamic dispersion
Abstract: A better understanding is needed of the factors
that control the rate of chemicals that move laterally in
shallow groundwater within fields to tile lines and drainage
ditches and from fields to nearby streams or estuaries. A
chamber was designed and used to simulate shallow groundwater
flow in the field. The chamber, made of Plexiglas with
dimensions 120 by 60 by 60 cm, was filled to a depth of 30 cm
with sand. A multiport arrangement of 10-mm-diam. holes on a 5
by 5 cm grid on both end walls of the chamber provided a
combination for quite uniform solute application at the inlet
side, and allowed sampling simultaneously from all ports at
the outlet side. As a first approximation, the flow and
transport were assumed to be one dimensional, and a
convective-dispersive solute-transport model was applied to
the Cl breakthrough data of each of the 50 outlet ports in
order to quantify the spatial distribution of the dispersion-
coefficient values at the outlet plate. Based on the
inconsistency observed between measured and estimated pore-
water velocities and dispersion coefficients of each of the 50
outlet ports, it appears that the one-dimensional model is not
appropriate to adequately characterize transport parameter in
this horizontal flow system.
299 NAL Call. No.: RA1270.P35A1
Transport of a BTX mixture in a groundwater aquifer material.
Uchrin, C.G.; Katz, J.
New York, N.Y. : Springer-Verlag; 1991 Apr.
Bulletin of environmental contamination and toxicology v. 46
(4): p. 534-541; 1991 Apr. Includes references.
Language: English
Descriptors: New Jersey; Petroleum; Benzene; Toluene; Xylene;
Flow; Leaching; Aquifers; Groundwater; Mathematical models
300 NAL Call. No.: 30 AD9
Transport of chemicals through soil: mechanisms, models, and
field applications.
Jury, W.A.; Fluhler, H.
San Diego, Calif. : Academic Press; 1992.
Advances in agronomy v. 47: p. 141-210; 1992. Literature
review. Includes references.
Language: English
Descriptors: Soil chemistry; Movement in soil; Solutes;
Transport processes; Literature reviews; Mathematical models
301 NAL Call. No.: QH540.N3
Transport of linearly reactive solutes in porous media. Basic
models and concepts.
Schweich, D.
Berlin, W. Ger. : Springer-Verlag; 1993.
NATO ASI series : Series G : Ecological sciences v. 32: p.
221-245; 1993. In the series analytic: Migration and fate of
pollutants in soils and subsoils / edited by D. Petruzzelli
and F.G. Helfferich. Proceedings of the NATO Advanced Study
Institute, May 24-June 5, 1992, Maratea, Italy. Includes
references.
Language: English
Descriptors: Soil pollution; Pollutants; Transport processes;
Equations; Mathematical models; Soil water movement;
Groundwater flow
302 NAL Call. No.: 56.8 J823
Two models for the leaching of a non-reactive solute to a mole
drain. Scotter, D.R.; Heng, L.K.; White, R.E.
Oxford : Blackwell Scientific Publications; 1991 Dec.
The Journal of soil science v. 42 (4): p. 565-576; 1991 Dec.
Includes references.
Language: English
Descriptors: Mole drainage; Solutes; Losses from soil;
Simulation models; Mathematical models; Silt loam soils;
Potassium chloride; Chloride; Leaching
Abstract: Two models of solute leaching to a mole-pipe
drainage system are described. The first model is research-
oriented. It simplifies two-dimensional water and solute flow
to a mole drain by dividing the soil between the mid-mole
plane and the mole into notional compartments. Solute movement
between compartments is assumed to occur by convection and
mechanical dispersion. Within each compartment a mobile and
immobile solute phase is defined, with diffusion occurring
between them. Rainfall intensity (over approximately hourly,
intervals) and basic soil hydraulic data are needed as inputs.
An explicit finite-difference solution to the water and solute
mass-balance and flux equations is used. The second simpler
model is management-oriented. It uses daily time steps, and
assumes the soil solution behaves as if it were a well-mixed
system. It requires only-daily rainfall and evaporation data,
the drainage coefficient of the mole-pipe system, and the soil
macroporosity as inputs. In both models a source/sink term
accounts for additions of solute in rainfall and fertilizer,
and extraction by plant uptake. The models were used to
simulate leaching, losses of chloride to a mole-pipe drainage
system in a silt loam under pasture, following the application
of potassium chloride to the soil surface. The first model
simulated leaching better immediately after fertilizer
application, and during bypass flow, induced by heavy rain.
However both models were able to simulate the measured losses
over a 2-year period equally well.
303 NAL Call. No.: TC401.W27
Two new characteristic parameters for runoff computation. Leu,
J.M.; Liu, C.L.
Dordrecht : Kluwer Academic Publishers; 1992.
Water resources management v. 6 (1): p. 165-184; 1992.
Includes references.
Language: English
Descriptors: Taiwan; Rain; Runoff; Watersheds; Models
304 NAL Call. No.: 290.9 AM32T
Uncertainty analysis of the WEPP soil erosion model.
Chasves, H.M.L.; Nearing, M.A.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 Nov. Transactions of the ASAE v. 34 (6): p.
2437-2444; 1991 Nov. Includes references.
Language: English
Descriptors: Water erosion; Prediction; Losses from soil
systems; Simulation models
Abstract: Predictions from hydrologic and erosion models
contain a large degree of uncertainty. The Modified Point
Estimate Method (Harr, 1989) used in conjunction with a
response surface exploration technique (Brooks, 1958) provides
a simple, computationally efficient, and powerful tool for
evaluating uncertainty of predictions by natural-resource
models. The method allows analysis of models with a large
number of input parameters which may be correlated and for
which the exact input parameter distribution is unknown. The
method was applied to the Water Erosion Prediction Project
single rainfall-event erosion model. Sixty treatment
combinations were selected to determine WEPP output
uncertainties for a wide range of soil, crop, management,
topographic, and storm conditions. The levels of the treatment
combinations were randomly selected to span the entire
factorial space of the 28 WEPP inputs, but with a finite
number of treatment combinations. Five WEPP outputs were
studied: peak runoff rate, average soil loss, average
deposition, sediment yield, and sediment specific surface
enrichment ratio. Maximum and average output uncertainties,
given by the coefficient of variation, were determined for
each output of the 60 treatments. Maximum coefficients of
variation for peak runoff rate, soil loss, sediment yield, and
sediment enrichment ratio were 196, 267, 323, and 47%,
respectively. Average coefficients of variation for the same
set of variables were 65, 99, 106, and 13%, respectively.
Coefficient of variation was less for larger runoff and
erosion events, which account for a large percentage of the
total soil loss at a location over extended time periods.
Significant, positive correlations existed between the
coefficients of variation of peak runoff average soil loss,
and average soil loss and sediment yield, indicating that the
uncertainty in average soil loss and in sediment yield may be
directly related to the uncertainty in peak runoff rate.
305 NAL Call. No.: 56.8 SO3
Unsaturated hydraulic characteristics of composted
agricultural wastes, tuff, and their mixtures.
Wallace, R.; Silva, F.F. da; Chen, Y.
Baltimore, Md. : Williams & Wilkins; 1992 Jun.
Soil science v. 153 (6): p. 434-441; 1992 Jun. Includes
references.
Language: English
Descriptors: Composts; Grape marc; Volcanic ash; Mixtures;
Culture media; Pot culture; Unsaturated hydraulic
conductivity; Determination; Mathematical models; Soil water
retention; Soil water potential; Saturated hydraulic
conductivity; Hysteresis; Crop management; Fertilizers;
Irrigation
306 NAL Call. No.: 56.9 SO3
Urea transformations in flooded soil columns. II. Derivation
of model and implications to ammonia volatilization.
Bouldin, D.R.; Hongprayoon, C.; Lindau, C.W.; Patrick, W.H. Jr
Madison, Wis. : The Society; 1991 Jul.
Soil Science Society of America journal v. 55 (4): p.
1135-1142; 1991 Jul. Includes references.
Language: English
Descriptors: Oryza sativa; Silt loam soils; Urea; Transport
processes; Volatilization; Ammonia; Losses from soil systems;
Diffusion; Hydrolysis; Sorption; Ammonium nitrogen;
Diffusivity; Mathematical models; Soil management;
Incorporation; Depth; Ph; Temperature; Flooded rice; Paddy
soils; Laboratory methods
Abstract: Ammonia volatilization from rice (Oryza sativa L.)
paddies following urea application reduces the effectiveness
of the urea-N. The objectives of this study were to: (i)
derive, for flooded soils, a model describing hydrolysis and
diffusion of urea and diffusion of ammoniacal N; (ii) derive
the necessary parameters from experimental data, and (iii) use
the model to study implications of hydrolysis/transport sport
parameters and management variables to NH3 volatilization. The
parameters are diffusion coefficients of urea and NH4, in soil
hydrolysis coefficients of urea in the soil and overlying
floodwater, and the sorption coefficient for NH4 on the soil.
The effects on potential for NH3 volatilization of variation
in these parameters and the management factors of depth of
flood water and depth of fertilizer incorporation were
calculated. The results illustrate that urea-hydrolysis rates
in the floodwater and soil are the most important factors
influencing the potential for NH3 volatilization. If urea-
hydrolysis rates are very high, incorporation and shallow
floodwater are the indicated management while, with low
hydrolysis rates, deep floodwater and no incorporation are the
indicated management.
307 NAL Call. No.: 56.8 J822
Use of a geographic information system for selection of sites
for land application of sewage waste.
Hendrix, W.G.; Buckley, D.J.A.
Ankeny, Iowa : Soil and Water Conservation Society of America;
1992 May. Journal of soil and water conservation v. 47 (3): p.
271-275; 1992 May. Includes references.
Language: English
Descriptors: Vermont; Agricultural land; Forests; Land types;
Sewage effluent; Sewage effluent disposal; Waste disposal
sites; Selection methods; Information systems; Geography;
Computer techniques; Site factors; Soil variability; Soil
physical properties; Land use; Topography; Social values;
Environmental legislation; Models
308 NAL Call. No.: GB701.W375 no.90-4140
Use of a geographic information system to assess risk to
ground-water quality at public-supply wells, Cape Cod,
Massachusetts.
Olimpio, Julio C.
Massachusetts, Division of Water Pollution Control, Geological
Survey (U.S.) Boston, Mass. : U.S. Dept. of the Interior, U.S.
Geological Survey ; Denver, CO : Books and Open-File Reports
Section [distributor],; 1991; I 19.42/4:90-4140.
v, 35, 10 p. : ill., maps (some col.) ; 28 cm. (Water-
resources investigations report ; 90-4140). Shipping list
no.: 91-790-P. Includes bibliographical references (p. 35).
Language: English
Descriptors: Water quality; Geographic information systems;
Water, Underground
309 NAL Call. No.: QH545.A1E58
Use of gleams to predict insecticide losses from pine seed
orchards. Nutter, W.L.; Knisel, W.G. Jr; Bush, P.B.; Taylor,
J.W.
Tarrytown, Y. : Pergamon Press; 1993 Mar.
Environmental toxicology and chemistry v. 12 (3): p. 441-452;
1993 Mar. Paper presented at the "Symposium on Pesticides in
Forest Management, 11th Annual Meeting of the Society of
Environmental Toxicology and Chemistry," November 11-15, 1990,
Arlington, Virginia. Includes references.
Language: English
Descriptors: Southern states of U.S.A.; Carbofuran; Azinphos-
methyl; Fenvalerate; Permethrin; Leaching; Groundwater;
Runoff; Vertical movement; Surface water; Seed orchards;
Simulation models; Prediction
310 NAL Call. No.: S671.A66
The use of graphics to present the results of erosion models.
Bingner, R.L.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 Mar. Applied engineering in agriculture v. 7
(2): p. 193-197; 1991 Mar. Includes references.
Language: English
Descriptors: Erosion; Models; Watersheds; Computer software;
Graphic arts; Runoff
Abstract: This study shows how graphical representations of a
watershed system can be used to analyze the runoff and
sediment yield. Combining output data from an erosion model,
such as runoff, sediment yield, and particle size distribution
of the eroded sediment, onto a single screen on a computer
monitor, permits immediate analysis as a rainfall event
occurs. This study shows how the erosion models CREAMS and
ANSWERS can be modified for simulations on small and large
watersheds, using graphics to enhance the results.
311 NAL Call. No.: SB610.W39
Use of modeling in developing label restrictions for
agricultural chemicals. Jones, R.L.
Champaign, Ill. : The Society; 1992 Jul.
Weed technology : a journal of the Weed Science Society of
America v. 6 (3): p. 683-687; 1992 Jul. Paper presented at a
Symposium on the, "Role of Modeling in Regulatory Affairs," at
the Weed Science Society of America, February 4, 1991,
Louisville, Kentucky. Includes references.
Language: English
Descriptors: Agricultural chemicals; Pesticides; Simulation
models; Regulations; Labeling; Groundwater; Drinking water;
Water quality
312 NAL Call. No.: 60.18 J82
Use of stochastically generated weather records with rangeland
simulation models.
Wight, J.R.; Hanson, C.L.
Denver, Colo. : Society for Range Management; 1991 May.
Journal of range management v. 44 (3): p. 282-285; 1991 May.
Includes references.
Language: English
Descriptors: Rangelands; Herbage; Crop yield; Prediction;
Simulation models; Weather data; Runoff; Precipitation; Air
temperature; Solar radiation; Stochastic models; Yield
forecasting; Hydrological data
Abstract: We compared long-term historical and stochastically
generated weather records in terms of their statistical
attributes and effects on herbage yield and runoff forecasts
calculated from model simulations. The historical and
synthetic air temperature and solar radiation records were in
good agreement in terms of monthly means and extremes. The
synthetic precipitation record failed to simulate extreme
precipitation events which significantly reduced forecasted
runoff values. Yield forecasts were similar using either
historical or synthetic weather records.
313 NAL Call. No.: HC79.E5E5
Use of wetlands for water quality improvement under USEPA
Region V Clean Lakes Programs.
Landers, J.C.; Knuth, B.A.
New York, N.Y. : Springer-Verlag; 1991 Mar.
Environmental management v. 15 (2): p. 151-162; 1991 Mar.
Includes references.
Language: English
Descriptors: Minnesota; Wisconsin; Indiana; Wetlands; Lakes;
Water quality; Environmental protection; Runoff water; Land
management; Program evaluation; Models; Land diversion;
Federal programs
314 NAL Call. No.: SD421.37.C6 1991
Using a GIS to document relationships between disturbance and
sedimentation following salvage logging.
Wells, W.G. II; Napoleon, E.J.; Wohlgemuth, P.M.
Bethesda, Md. : Society of American Foresters; 1991.
Proceedings of the 11th Conference on Fire and Forest
Meteorology, April 16-19, 1991, Missoula, Montana / sponsored
by the Society of American Foresters and American
Meteorological Soc. ; editors, P.L. Andrews and D.F. Potts. p.
405-411; 1991. This record corrects IND 92025711 which was
entered incorrectly under call number SD143.S64. Includes
references.
Language: English
Descriptors: California; Salvage felling and logging; Erosion;
Sediment
315 NAL Call. No.: 60.18 UN33
Using computer situations to predict the fate and
environmental impact of applied pesticides.
Franke, K.J.
Far Hills, N.J. : United States Golf Association; 1992 Mar.
USGA Green Section record v. 30 (2): p. 17-21; 1992 Mar.
Language: English
Descriptors: Lawns and turf; Golf courses; Pesticides;
Integrated pest management; Environmental impact; Computer
simulation
316 NAL Call. No.: 10 OU8
Using crop models for sustainability and environmental quality
assessment. Singh, U.; Thornton, P.K.
Oxon : C.A.B. International; 1992.
Outlook on agriculture v. 21 (3): p. 209-218; 1992. Includes
references.
Language: English
Descriptors: Crop production; Environmental impact; Leaching;
Nitrogen fertilizers; Pollution; Simulation models;
Sustainability
317 NAL Call. No.: 56.9 SO32
Using geographic information systems in a well permitting
program. Myhre, B.E.; Shih, S.F.
S.l. : The Society; 1991.
Proceedings - Soil and Crop Science Society of Florida v. 50:
p. 102-105; 1991. Paper presented at the "Symposium on
Reality of Sustainable Agriculture in Florida, September
26-28, 1990, Daytona Beach, FLorida. Includes references.
Language: English
Descriptors: Florida; Groundwater; Water quality; Wells;
Geographical distribution
318 NAL Call. No.: 56.9 SO32
Using landsat data and geographic information system for
wetland assessment in water-quality management.
Still, D.A.; Shih, S.F.
S.l. : The Society; 1991.
Proceedings - Soil and Crop Science Society of Florida v. 50:
p. 98-102; 1991. Paper presented at the "Symposium on Reality
of Sustainable Agriculture in Florida, September 26-28, 1990,
Daytona Beach, FLorida. Includes references.
Language: English
Descriptors: Florida; Wetlands; Water quality; Assessment;
Landsat
319 NAL Call. No.: 292.9 AM34
Using soil texture to estimate saturated hydraulic
conductivity and the impact on rainfall-runoff simulations.
Loague, K.
Bethesda, Md. : American Water Resources Association; 1992
Jul. Water resources bulletin v. 28 (4): p. 687-693; 1992 Jul.
Includes references.
Language: English
Descriptors: Rangelands; Rangeland soils; Soil texture;
Saturated hydraulic conductivity; Infiltration; Rain; Runoff;
Simulation models; Mathematical models
Abstract: In this paper a new set of soil texture data is
used to estimate the spatial distribution or saturated
hydraulic conductivity values for a small rangeland catchment.
The estimates of conductivity are used to re-excite and re-
evaluate a quasi-physically based rainfall-runoff model. The
performance or the model is significantly reduced with
conductivity estimates gleaned from soil texture data rather
than the infiltration data used in our previous efforts.
320 NAL Call. No.: 290.9 AM32T
Using the ANSWERS model to predict runoff and soil loss in
southwestern Quebec.
Montas, H.J.; Madramootoo, C.A.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 Jul. Transactions of the ASAE v. 34 (4): p.
1754-1762; 1991 Jul. Includes references.
Language: English
Descriptors: Quebec; Losses from soil systems; Runoff;
Sediment; Computer simulation; Erosion; Watersheds
Abstract: The distributed parameter model ANSWERS was used to
predict runoff and soil loss for two small agricultural
watersheds in southwestern Quebec. Runoff predictions were
compared for 24 observed events. Peak flow was generally
underpredicted and time to peak was overpredicted. A seasonal
adjustment of infiltration parameters was derived to account
for crusting and sealing of the soils in the spring and fall.
Runoff predictions with adjusted parameters were better than
those with measured parameters. Predictions of sediment
concentration and yield, with adjusted infiltration
parameters, were compared with seven observed storm events.
ANSWERS underpredicted sediment yield for all events.
321 NAL Call. No.: 290.9 AM32T
Validating GLEAMS with pesticide field data on a Clermont silt
loam soil. Sichani, S.A.; Engel, B.A.; Monke, E.J.; Eigel,
J.D.; Kladivko, E.J. St. Joseph, Mich. : American Society of
Agricultural Engineers; 1991 Jul. Transactions of the ASAE v.
34 (4): p. 1732-1737; 1991 Jul. Includes references.
Language: English
Descriptors: Indiana; Alachlor; Atrazine; Cyanazine;
Carbofuran; Chlorpyrifos; Groundwater; Leaching; Simulation
models; Water pollution
Abstract: The GLEAMS (Groundwater Loading Effects of
Agricultural Management Systems) model was used to simulate
the appearances of pesticides in outflow of an experimental
drainage field at the South East Purdue Agricultural Center
(SEPAC) in southeastern Indiana. This article presents the
comparison of simulated and observed loading of Alachlor,
Atrazine, Cyanazine, Carbofuran, and Chlorpyrifos in tile
outflows for 1985 through 1989. Me results of the simulation
were close to field observations for total masses of
pesticides leached from the root zone and for the overall
timing of pesticide appearance in tile flows. However, the
simulation of the watershed did not predict the observed
arrival of pesticides in the drain during the first storm
event after pesticide application. To compare the simulated
results from on-site weather data and the data from nearby
locations, long-term mean monthly solar radiation data for
SEPAC and Indianapolis, Indiana were evaluated.
322 NAL Call. No.: FICHE S-72
Validation of WEPP 91.2 with erosion plot data.
Kramer, L.A.; Alberts, E.E.; Ghidey, F.
St. Joseph, Mich. : The Society; 1991.
American Society of Agricultural Engineers (Microfiche
collection) (fiche no. 91-2079): 16 p.; 1991. Paper presented
at the 1991 Summer Meeting of the American Society of
Agricultural Engineers held June 23-26, 1991, Albuquerque, New
Mexico. Includes references.
Language: English
Descriptors: Water erosion; Prediction; Simulation models;
Runoff; Losses from soil systems; Experimental plots; Tillage;
Zea mays; Regression analysis
323 NAL Call. No.: 292.8 W295
Vapor transport in unsaturated soil columns: implications for
vapor extraction.
Gierke, J.S.; Hutzler, N.J.; McKenzie, D.B.
Washington, D.C. : American Geophysical Union; 1992 Feb.
Water resources research v. 28 (2): p. 323-335; 1992 Feb.
Includes references.
Language: English
Descriptors: Soil pollution; Contaminants; Toluene; Methane;
Vapor; Extraction; Transport processes; Sand; Aggregates;
Mathematical models
Abstract: A mathematical model was derived to examine the
impact of gas advection, gas diffusion, gas-water mass
transfer, gas-water partitioning, sorption, and intraaggregate
diffusion on subsurface movement of organic vapors. Laboratory
experiments were performed to determine the validity of the
model and to investigate the impact of the various mechanisms
on vapor transport, Columns were packed with a uniform Ottawa
sand and an aggregated porous soil material (APSM) to compare
transport in different soil structures. Toluene vapor
transport was observed in the sand under dry and wet (27%
water saturation) conditions. The experiments with the APSM
were performed dry and at 67% water saturation. in all the
sand and the dry APSM experiments, gas advection and diffusion
had the greatest impact. In a wet APSM experiment,
intraaggregate (liquid) diffusion was also important to
consider for gas velocities greater than approximately 0.05 cm
s-1. For both soil materials, sorption of toluene vapors
occurred for dry conditions, while vapor sorption was
negligible when liquid water was present. These findings imply
that vapor extraction performance in moist, aggregated soils
will be affected by nonequilibrium transport. Therefore models
that are developed for predicting the complete removal of
contaminants by vapor extraction must account for
nonequilibrium.
324 NAL Call. No.: 290.9 AM32T
Variability of optimized parameter estimates based on observed
record length. Allred, B.; Haan, C.T.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1991 Nov. Transactions of the ASAE v. 34 (6): p.
2421-2426. maps; 1991 Nov. Includes references.
Language: English
Descriptors: Oklahoma; Arkansas; Hydrology; Rain; Runoff;
Stream flow; Watersheds; Mathematical models
Abstract: The variability in parameter estimates for a
hydrologic model as a function of the number of years of data
available for estimating the parameters was investigated. A
25-year record on Spavinaw Creek in Oklahoma and Arkansas was
divided into 25 one-year, 12 two-year, and 5 five-year
records. Each period was used for parameter estimation. Two
objective functions, one based on absolute errors and one
based on error sum of squares, were used. Mean parameter
values exhibited greater than expected variability, and
variances in estimated parameters did not decrease as expected
as the number of years used for parameter estimation increased
from one to five years. One year was found to dominate one of
the estimated model parameters for any record length that
included that particular year. Significant differences between
parameter values based on the two objective functions were
found only for one parameter based on one-year optimizations.
325 NAL Call. No.: 448.3 AP5
VIRTUS, a model of virus transport in unsaturated soils.
Yates, M.V.; Ouyang, Y.
Washington, D.C. : American Society for Microbiology; 1992
May. Applied and environmental microbiology v. 58 (5): p.
1609-1616; 1992 May. Includes references.
Language: English
Descriptors: Groundwater; Viruses; Transport processes; Soil
water content; Soil water regimes; Movement in soil;
Inactivation; Soil temperature; Pollutants; Models
Abstract: As a result of the recently proposed mandatory
groundwater disinfection requirements to inactivate viruses in
potable water supplies, there has been increasing interest in
virus fate and transport in the subsurface. Several models
have been developed to predict the fate of viruses in
groundwater, but few include transport in the unsaturated zone
and all require a constant virus inactivation rate. These are
serious limitations in the models, as it has been well
documented that considerable virus removal occurs in the
unsaturated zone and that the inactivation rate of viruses is
dependent on environmental conditions. The purpose of this
research was to develop a predictive model of virus fate and
transport in unsaturated soils that allows the virus
inactivation rate to vary on the basis of changes in soil
temperature. The model was developed on the basis of the law
of mass conservation of a contaminant in porous media and
couples the flows of water, viruses, and heat through the
soil. Model predictions were compared with measured data of
virus transport in laboratory column studies and, with the
exception of one point, were within the 95% confidence limits
of the measured concentrations. The model should be a useful
tool for anyone wishing to estimate the number of viruses
entering groundwater after traveling through the soil from a
contamination source. In addition, model simulations were
performed to identify parameters that have a large effect on
the results. This information can be used to help design
experiments so that important variables are measured
accurately.
326 NAL Call. No.: 292.8 J82
Water balance and soil moisture dynamics of field plots with
barley and grass ley.
Johnsson, H.; Hansson, P.E.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1991 Dec.
Journal of hydrology v. 129 (1/4): p. 149-173; 1991 Dec.
Includes references.
Language: English
Descriptors: Sweden; Hordeum vulgare; Festuca pratensis; Leys;
Arable land; Nitrogen fertilizers; Soil water; Soil water
balance; Evapotranspiration; Evaporation; Transpiration; Soil
physical properties; Plant development; Meteorological
factors; Drainage; Runoff; Precipitation; Simulation; Physical
models
Abstract: A physically based soilwater and heat model was
used to estimate the water balance of an arable field in
central Sweden for each of three different crop covers (barley
with and without N fertilization and grass ley). Annual water
balances were calculated for each year from 1981 to 1985. On-
site measurements of soil physical properties, meteorological
variables and plant development were used as input to the
model. Simulated soil frost, snow cover, soilwater contents,
soilwater tensions and relative differences in simulated
drainage between treatments were in agreement with the
corresponding measured values. In the simulation, surface
runoff (70 mm year-1 in all treatments) mainly occurred during
snowmelt periods and accounted for much of the variation in
the total runoff estimate. Annual mean precipitation amounted
to 610 mm year-1, whereas average evapotranspiration was
calculated to be 320, 360 and 435 mm year-1 in barley without
N fertilization, barley with N fertilization and grass ley,
respectively. Soil evaporation accounted for 60, 43 and 23%
whereas evaporation of intercepted water accounted for 5, 12
and 19% of the total evapotranspiration, respectively.
Drainage estimates amounted to 205, 170 and 110 mm year-1.
327 NAL Call. No.: 56.8 J822
Water balance components in the Georgia Coastal Plain: a
GLEAMS model validation and simulation.
Knisel, W.G.; Leonard, R.A.; Davis, F.M.; Sheridan, J.M.
Ankeny, Iowa : Soil and Water Conservation Society of America;
1991 Nov. Journal of soil and water conservation v. 46 (6): p.
450-456; 1991 Nov. Includes references.
Language: English
Descriptors: Georgia; Watersheds; Rain; Runoff; Subsurface
drainage; Water balance; Simulation models; Validity
328 NAL Call. No.: 280.8 J822
Water markets and water quality.
Weinberg, M.; Kling, C.L.; Wilen, J.E.
Ames, Iowa : American Agricultural Economics Association; 1993
May. American journal of agricultural economics v. 75 (2): p.
278-291; 1993 May. Includes references.
Language: English
Descriptors: U.S.A.; Water quality; Irrigation water; Markets;
Water use efficiency; Water allocation; Farm management;
Decision making; Drainage; Simulation models; Water policy
Abstract: In addition to improving the allocative efficiency
of water use, water markets may reduce irrigation-related
water quality problems. This potential benefit is examined
with a nonlinear programming model developed to simulate
agricultural decision-making in a drainage problem area in
California's San Joaquin Valley. Results indicate that a 30%
drainage goal is achievable through improvements in irrigation
practices and changes in cropping patterns induced by a water
market. Although water markets will not generally achieve a
least-cost solution, they may be a practical alternative to
economically efficient, but informationally intensive,
environmental policies such as Pigouvian taxes.
329 NAL Call. No.: TD419.5.W365 1991
Water pollution modelling, measuring, and prediction.
Brebbia, C. A.; Wrobel, L. C.
International Conference on Water Pollution: Modelling,
Measuring, and Prediction 1st : 1991 : Southampton, England.
Southampton ; Boston : Computational Mechanics Pub. ; London ;
New York : Elsevier Applied Science,; 1991.
748 p. : ill. ; 24 cm. "Contains the edited versions of some
of the papers presented at the First International Conference
on Water Pollution: Modelling, Measuring and Prediction"--P. 4
of cover. Includes bibliographical references and index.
Language: English
Descriptors: Water; Water quality; Sewage
330 NAL Call. No.: 302.8 T162
Water quality and biological investigation of the lower Cape
Fear River Basin. Kreutzberger, W.A.; Wakild, C.R.
Norcross, Ga. : The Technical Association of the Pulp and
Paper Industry; 1993 Jul.
Tappi journal v. 76 (7): p. 169-177; 1993 Jul. Includes
references.
Language: English
Descriptors: North Carolina; Pulp and paper industry; Pulp
mill effluent; Water quality; Biochemical oxygen demand;
Models; Rivers
331 NAL Call. No.: TD172.J6
Water quality modeling in distribution systems.
Clark, R.M.
New York, N.Y. : Marcel Dekker; 1992 Jul.
Journal of environmental science and health : Part A :
Environmental science and engineering v. 27 (5): p. 1329-1366;
1992 Jul. Includes references.
Language: English
Descriptors: U.S.A.; Drinking water; Water quality;
Deterioration; Quality standards; Law enforcement;
Environmental protection; Public agencies; Water distribution;
Systems; Health hazards
332 NAL Call. No.: TD482.W38 1991
Water quality modeling in distribution systems conference
proceedings, February 4-5, 1991, Cincinnati, Ohio..
Proceedings, water quality modeling in distribution systems
AWWA Research Foundation, United States, Environmental
Protection Agency Denver, Colo. : The Foundation,; 1991.
viii, 469 p. : ill., maps ; 23 cm. Cover title: Proceedings,
water quality modeling in distribution systems. Includes
bibliographical references and index.
Language: English
Descriptors: Water quality; Water
333 NAL Call. No.: TD370.W3957 1992
Water quality modelling.
Falconer, R. A.
Institution of Water and Environmental Management
Aldershot, Hants, England ; Brookfield, Vt., USA : Ashgate,;
1992. xii, 139 p. : ill. ; 24 cm. Published in association
with the Institution of Water and Environmental Management.
Papers from a one day symposium given by the IWEM and held in
Harrogate on 11/13/91. Includes bibliographical references.
Language: English
Descriptors: Water quality
334 NAL Call. No.: 290.9 AM32T
Water table management practice effects on water quality.
Wright, J.A.; Shirmohammadi, A.; Magette, W.L.; Fouss, J.L.;
Bengtson, R.L.; Parsons, J.E.
St. Joseph, Mich. : American Society of Agricultural
Engineers; 1992 May. Transactions of the ASAE v. 35 (3): p.
823-831; 1992 May. Includes references.
Language: English
Descriptors: Water management; Water quality; Water table;
Drainage; Hydrology; Simulation models; Subsurface irrigation
Abstract: Impacts of water table management (WTM) practices
on water quality were modeled using a linked version of CREAMS
and DRAINMOD (Parsons and Skaggs, 1988). The CREAMS
denitrification component and the linked DRAINMOD-CREAMS model
were modified to simulate daily hydrology (runoff,
infiltration, evaporation, and soil moisture content),
erosion, and nutrient processes for different WTM conditions.
Measured data from Baton Rouge, Louisiana, were used to
validate the linked model, and then controlled drainage-
subirrigation (CD-SI) was simulated to investigate the effects
of different WTM systems on runoff, erosion, and nitrogen
losses. Results of the study indicated that the linked models
performed better than the original CREAMS model in predicting
runoff, infiltration, soil moisture content, and erosion, and
that the modified linked model performed better than both
CREAMS and the original linked model in predicting nitrogen
losses from the study site. Results also showed that the CD-SI
system simulated by the modified DRAINMOD-CREAMS model
predicted increased denitrification and lowered nitrate
leaching, unlike the original version. This study concluded
that the CD-SI system may be used as a BMP to reduce nitrogen
leaching to shallow groundwater systems for areas with high
water table conditions.
335 NAL Call. No.: 292.8 J82
Water vapor transfer beneath bare soil where evaporation is
influenced by a turbulent surface wind.
Ishihara, Y.; Shimojima, E.; Harada, H.
Amsterdam : Elsevier Scientific Publishers, B.V.; 1992 Feb.
Journal of hydrology v. 131 (1/4): p. 63-104; 1992 Feb.
Includes references.
Language: English
Descriptors: Soil types; Subsurface layers; Water vapor;
Evaporation; Transport processes; Diffusion; Diffusivity;
Wind; Turbulent flow; Air flow; Particle size; Mathematical
models
Abstract: A laboratory experiment on evaporation in various
porous material layers was undertaken by applying a turbulent
air flow to the exposed surface, to investigate the mechanism
of the water vapor transport beneath a bare ground surface
influenced by a turbulent surface wind. Variation of air
pressure within these layers was also measured. Based on a
physical model of water vapor transfer, an observed function
decribing bulk resistance for water vapor transfer with
evaporating front depth was investigated, using an observed
power spectrum of the pore-air pressure. The model is based on
the so-called turbulent mixing theory. The following
conclusions were reached. When porous material layers are of
low permeability such as fine sand, water vapor transfer under
the exposed surface occurs by molecular diffusion as well as
by turbulent diffusion caused by variation of the pore-air
pressure due to the turbulent surface wind (P-type). The
surface turbulence significantly affects the transport just
beneath the surface. Turbulent diffusivity near the surface is
determined by horizontal and vertical fluctuating components
of the pore-air pressure, but with increasing depth is driven
only by the vertical component. When the porous material layer
is more permeable, water vapor transfer in this layer is
analogous to that within a vegetation canopy (F-type), so that
turbulent diffusivity decays exponentially with depth. The
turbulent diffusivity is a function of the mixing length. The
mixing length for F-type was of the order of the particle
size. For P-type the mixing length ranged from the particle
size to ten times larger.
336 NAL Call. No.: 56.8 J822
WEPP: a new generation of erosion prediction technology.
Laflen, J.M.; Lane, L.J.; Foster, G.R.
Ankeny, Iowa : Soil and Water Conservation Society of America;
1991 Jan. Journal of soil and water conservation v. 46 (1): p.
34-38; 1991 Jan. Includes references.
Language: English
Descriptors: Erosion; Universal soil loss equation;
Prediction; Water erosion
337 NAL Call. No.: 56.8 J822
WEPP: soil erodibility experiments for rangeland and cropland
soils. Laflen, J.M.; Elliot, W.J.; Simanton, J.R.; Holzhey,
C.S.; Kohl, K.D. Ankeny, Iowa : Soil and Water Conservation
Society of America; 1991 Jan. Journal of soil and water
conservation v. 46 (1): p. 39-44; 1991 Jan. Includes
references.
Language: English
Descriptors: Water erosion; Prediction; Rangelands; Equations;
Erodibility; Rill erosion; Crops; Soil
# # #
Author Index
Abriola, L.M. 291
Adams, R.M. 206
Addiscott, T.M. 233
Adelman, D. 191
Adrian, D.D. 210
Aharoni, C. 127
Ahern, Jack 129
Ahlfeld, D.P. 88
Ahuja, L.R. 22
Alberts, E.E. 322
Alemi, M.H. 168
Allen, G. 114
Allen, H.E. 295
Allen, P.M. 28
Allen, Roderick L. 227
Allred, B. 324
Altafin, I. 137
Amacher, G. 231
Ammentorp, H.C. 157
Antle, J.M. 215
Arnold, J.A. 196, 197
Arnold, J.G. 19, 28
Ashraf, M.S. 167
Asmussen, L.E. 277
Aubry, B.F. 62
Avila, A. 246
AWWA Research Foundation, United States, Environmental
Protection Agency 332
Aylmore, L.A.G. 152
Bach, L.B. 266
Bahr, J.M. 296
Baker, D.E. 258
Banks, P.A. 27
Bar-Yosef, B. 91
Barnes, B.B. 22
Barnes, N.L. 106
Barrington, S.F. 78
Barry, D.A. 84
Batie, S.S. 116, 135
Baumer, G.M. 272
Beck, R.M. 111
Behl, E. 30
Behrendt, H. 214
Ben-Asher, J. 209
Bengtson, R.L. 179, 334
Benson, V.W. 194
Berg, W.A. 248
Bergstrom, L. 178
Berisford, Y.C. 175
Bernado, D.J. 68
Bernhard, C. 192
Bernhardt, G. 28
Beven, K.J. 71
Bhargava, D.S. 65
Billett, M.F. 224
Bingner, R.L. 226, 310
Black, A.S. 222
Blackburn, W.H. 34, 242
Blau, G.E. 237
Bloom, S.A. 85
Bode, L.E. 211
Boekhold, A.E. 134, 244
Boesen, C. 193
Boesten, J.J.T.I. 63, 171, 252
Bogardi, I. 142
Bogusch, H.C. 194
Borah, A. 113
Borah, D.K. 167
Bottcher, A.B. 95, 223
Bouldin, D.R. 306
Bouma, J. 148
Bouton, M. 273
Bowen, W.T. 81
Bradbury, N.J. 216
Braden, J.B. 115
Bradford, J.M. 13
Bras, R.L. 42, 125
Brebbia, C. A. 329
Brichford, S.L. 197
Britt, J.K. 143
Brooke, D. 47
Brooke, D.N. 146
Brusseau, M.L. 170
Brusven, M.A. 23
Buchter, B. 173
Buckley, D.J.A. 307
Burgoa, B. 85
Bush, P.B. 27, 89, 175, 309
Cabe, R. 232
Cabral, M.C. 125
Caldwell, D.E. 43
Campbell, K.L. 95
Capalbo, S.M. 215
Carbiener, R. 192
Carlson, C.G. 212
Carsel, R.F. 40, 48
Carsky, R.J. 81
Cary, Lawrence E. 286
Centner, T.J. 230
Chambers, L.W. 296
Chang, A.C. 74
Chasves, H.M.L. 304
Chen, B. 295
Chen, C. 261, 262
Chen, J.S. 85
Chen, W. 283
Chen, Y. 305
Christensen, T.H. 157
Chung, G.Y. 39
Chung, S.O. 80
Clark, R.M. 331
Cloots, A.R. 192
Coffey, S.W. 196, 197
Cohen, S.Z. 106
Coleman, G.A. 248
Comfort, S.D. 41, 288
Cooke, L. 29
Cooley, K.R. 238
Cooper, A.B. 223
Corapcioglu, M.Y. 188
Corradini, C. 162
Corwin, D.L. 98
Cresser, M.S. 224
Cubillo, F. 236
Curtis, B. 191
Dane, J.H. 58, 140, 182, 267
Daniel, T.C. 46, 153, 219
Darby, R.J. 233
Darrah, P.R. 149, 150
Davis, F.M. 213, 327
Day, R.L. 272
DeCoursey, D.G. 22
Deer, H.M. 20
Deizman, M.M. 156
Delong, M.D. 23
Destouni, G. 8, 59, 225, 276
Deverel, S.J. 249
Dhawan, S. 155
Dickinson, W.T. 77, 117
Diebel, P.L. 116, 135
Dik, P.E. 177, 178
Dillard, A.L. 32
Dillworth, M.E. 24
Dkstein, L. 142
Donigian, Anthony S. 166
Dowd, J.F. 175
Duckstein, L. 185, 234
Dudley, L.M. 158, 243
Dunne, T. 62
Dunnivant, F.M. 26
Durborow, T.E. 106
Dwinell, S.E. 143
Edwards, D.R. 46, 219
Ehteshami, M. 20
Eigel, J.D. 321
Ekholm, P. 79
El-Attar, H.A. 288
Elliot, W.J. 82, 337
Elliott, R.L. 68, 180
Ellsworth, T.R. 293, 294
Eltahir, E.A.B. 42
Engel, B.A. 321
Engel, Bernard A. 9
Engesgaard, P. 100
Entekhabi, D. 125
Environmental Research Laboratory (Athens, Ga.) 166
Erickson, L.E. 155
Ernst, F.F. 294
Espeby, B. 37
Euw, E.L. von 117
Fabos, Julius Gy 129
Falconer, R. A. 109, 333
Fan, L.T. 155
Farquhar, G.J. 203
Feng, J.S. 96, 283
Fermanich, K.J. 153
Ferrandino, F.J. 67
Finke, P.A. 148
Finkner, S.C. 110
Fio, J.L. 249
Fisher, A.C. 120
Flanagan, D.C. 12
Flanagan, M. 190
Florida Marine Research Institute, Florida Office of Coastal
Management 139
Fluhler, H. 300
Focazio, Michael J. 50
Foltz, J.C. 87
Fong, F.K. 289
Fontaine, D.D. 237
Fontaine, T.D. 86
Foster, G.R. 336
Fouss, J.L. 179, 334
Franke, K.J. 315
Froehlicher, R. 192
Fujii, R. 249
Gaber, H.M. 288
Gale, J.A. 196, 197
Gambolati, G. 198
Ganoulis, J. 235
Garbrecht, J. 64
Garrote, L. 125
Gaston, L.A. 221
Gel'fan, A.N. 53
Geleta, S. 68, 180
Geological Survey (U.S.) 31
Geological Survey (U.S.),California Regional Water Quality
Control Board--Colorado River Basin Region 75
Geological Survey (U.S.),Hampton Roads Planning District
Commission (Va.),Virginia Water Control Board 50
Gerke, H.H. 51
Gerritse, R.G. 152
Ghidey, F. 322
Gierke, J.S. 323
Gilley, J.E. 110
Glaser, P.H. 111
Glendinning, P.J. 146
Goh, K.M. 200, 201
Goldhamer, D.A. 168
Goodrich, D.C. 126
Goolsby, D.A. 60
Goss, D. 194
Goss, D.W. 245
Graham, D.N. 203
Graney, R.L. 25
Gray, W.G. 44
Green, R.E. 76, 274
Griggs, R.H. 180
Grismer, M.E. 52
Grunblatt, J. 103
Gutema, Y. 147
Guy, B.T. 77
Haan, C.T. 14, 113, 187, 324
Habaieb, H. 36
Haddad, Kenneth D. 139
Halliday, S.L. 16
Halstead, J.M. 116
Hamlett, J.M. 272
Hammers, W.E. 229
Hanemann, W.M. 120
Hanks, R.J. 158
Hansen, J.A. 1, 254
Hanson, C.L. 238, 312
Hansson, P.E. 326
Harada, H. 335
Harbor, J. 285
Harmsen, K. 133
Harper, J.K. 4
Harwell, J.H. 90
Hauser, V.L. 241
Havens, P.L. 237
Havis, R.N. 210
Hayashi, Y. 49
Hayot, C. 204, 205
Head, K.L. 142
Heatwole, C.D. 116, 135, 284
Hendrix, W.G. 307
Hendry, M.J. 43
Heng, L.K. 302
Herricks, E.E. 115
Herriges, J.A. 232
Hill, R.W. 20
Hills, R.G. 130, 247
Hino, M. 199
Hinz, C. 173
Hipp, B.W. 92
Hoag, D.L. 38
Holloway, D. 256
Holzhey, C.S. 337
Hongprayoon, C. 306
Hornsby, A.G. 38, 263
Host-Madsen, J. 128
Hostetler, J. 231
Huang, C.H. 13
Huang, C.P. 295
Huang, L.Q. 67, 270
Huber, Wayne C. 166
Hudson, D.B. 130, 247
Humborg, G. 209
Hummel, J.W. 82
Hummel, P.R. 40, 48
Hutzler, N.J. 323
Imhoff, J.C. 40, 48
Inskeep, W.P. 41, 288
Institution of Water and Environmental Management 333
Ishiguro, M. 268, 269
Ishihara, Y. 335
Islam, M.N. 124
Jabro, J.D. 258
Jacobsen, O.H. 136
Jakeman, A.J. 18
Jakubauskas, M.E. 24
James, A. 122
Jansson, P.E. 177
Jardine, P.M. 26
Jarvis, N.J. 177, 178
Jaynes, D.B. 94
Jennings, G.D. 196, 197
Jensen, K.H. 128
Jessup, R.E. 170
Jian, L.R. 108
Johnson, P.A. 216
Johnson, R.C. 11
Johnson, S.L. 206
Johnsson, H. 279, 326
Jones, J.W. 81
Jones, O.R. 241
Jones, Philip Edward James, 83
Jones, R.E. 27
Jones, R.L. 311
Jurinak, J.J. 243
Jury, W.A. 132, 293, 294, 300
Kamari, J. 79
Kamra, S.K. 250, 251
Kanda, M. 199
Kandil, H. 163
Katz, J. 299
Kawanishi, T. 49
Keefer, T.O. 126
Keeler, A.G. 120
Kelly, W.E. 191
Kenimer, A.L. 211
Kihou, N. 49
Kim, C.S. 231
Kinouchi, T. 199
Kipp, K.L. 100
Kirk, G.J.D. 169
Kirkland, M.R. 247
Kittle, J.L. Jr 40, 48
Kladivko, E.J. 321
Klein, M. 10
Kleveno, J.J. 76
Kling, C.L. 328
Knisel, W.G. 213, 327
Knisel, W.G. Jr 309
Knuth, B.A. 313
Knutson, R.D. 54
Kobylyanskii, G.V. 181
Kohl, K.D. 337
Kondrat'ev, S.A. 72
Kookana, R.S. 152
Kotovich, I.N. 181
Kozloff, K. 154
Kramer, L.A. 287, 322
Kramer, R.A. 116
Kreutzberger, W.A. 330
Kristiansen, H. 193
Kroes, J.G. 195
Kuchment, L.S. 53
Kuhn, Gerhard 21
Kunishi, H.M. 259
Kuo, C.H. 44
la Cour, Niels 129
Lacewell, R.D. 114
Laenen, Antonius 227
Laflen, J.M. 336, 337
Lafolie, F. 204, 205
Lam, D.C.L. 119
Landers, J.C. 313
Lane, L.J. 118, 336
Larsen, F. 193
Larsen, H.D. 228
Larson, R.S. 115
Lawrence, J.R. 43
Leatham, D.J. 114
Lee, D.J. 97
Lee, D.Y. 74
Lee, J. 295
Lee, J.G. 87
Leij, F.J. 7, 58, 136, 140, 172, 182, 267
Leonard, R.A. 61, 213, 327
Lerner, D.N. 253
Letson, D. 257
Leu, J.M. 303
Lin, J.C. 25
Lindau, C.W. 306
Linden, A.M.A. van der 171
Line, D.E. 196
Littlewood, I.G. 18
Liu, C.C.K. 96, 283
Liu, C.L. 303
Loague, K. 76, 96, 265, 274, 319
Loehr, R.C. 66
Lotse, E.G. 258
Loureiro, C.O. 291
Lovell, A.C. 114
Lowery, B. 153
Lucey, K.J. 60
Lundin, L.C. 279
Ma, L. 173
Macur, R.E. 41
Maddock, T. III 185
Madramootoo, C.A. 320
Magette, W.L. 159, 334
Makuch, J. 256
Malchow, H. 271
Mansell, R.S. 85
Mapp, H.P. 68
Marbun, O. 46
Mariam, D.W. 65
Martin, M.A. 87
Martinko, E.A. 24
Massachusetts Agricultural Experiment Station 129
Massachusetts, Division of Water Pollution Control, Geological
Survey (U.S.) 308
Matthew, R. G. S. 109
Matthies, M. 214
Matthiessen, P. 47, 146
May, L. 147
McCarthy, J.F. 26
McCoy, B.J. 35, 39
McDonnell, J.J. 160
McDowell, T.C. 143
McIntosh, C.S. 189
McIsaac, G.F. 82
McKenzie, D.B. 323
McMahon, T.A. 70
McNamara, J.P. 111
Meadows, J. Kevin 75
Melone, F. 162
Messing, I. 177
Meyer, C.R. 12
Michael, J.L. 89
Michel, A.N. 44
Miller, C.T. 163
Miller, D.A. 272
Milligan, J.H. 242
Mills, M.J. 146
Mills, W.C. 32
Ming, L.S. 108
Miranda, M.J. 112
Mitchell, J.K. 82, 211
Mohamoud, Y.M. 73
Moldrup, P. 1, 254
Monke, E.J. 321
Montas, H.J. 320
Moore, I.D. 287
Moore, J.A. 282
Mostaghimi, S. 156
Mueller, T.C. 27
Murphree, C.E. 226
Mutchler, C.K. 226
Myhre, B.E.� 317
Napoleon, E.J. 314
Nash, T. 285
Nathan, R.J. 70
National Council of the Paper Industry for Air and Stream
Improvement (U.S.) 278
Nearing, M.A. 304
Neary, D.G. 89, 175
Newman, J.B. �34
Nguyen, M.L. 200, 201
Nielsen, D.R. 168
Nkedi-Kizza, P. 85
Noegrohati, S. 229
Nofziger, D.L. 14
Nordstedt, R.A. 99
Norris, P.E. 68
Nutter, W.L. 309
Okwach, G.E. 17
Olimpio, Julio C. 308
Olson, R.L. 290
Opaluch, J.J. 3
Osmond, D.L. 196
Ottichilo, W.K. 103
Ouyang, Y. 325
Overton, Donald E., 264
Ozaki, Y. 49
Panday, S. 188
Pandey, S. 55
Paniconi, C. 198
Panuska, J.C. 287
Papatolios, K.T. 253
Parker, J.C. 84
Parlange, J.Y. 84, 141
Parlange, M.B. 141
Parrish, R.S. 289
Parsons, J.E. 334
Patrick, W.H. Jr 306
Penson, J.B. Jr 54
Peralta, R.C. 20
Perry, G.M. 206
Peterson, G.W. 272
Phillips, I.R. 222, 255
Pignatello, J.J. 67, 270
Pikes Peak Area Council of Governments, Geological Survey
(U.S.) 21
Pinder, G. 207
Pinder, G.F. 88
Pinol, J. 246
Piper, S. 105
Piper, S.L. 69
Plate, E.J. 234
Porro, I. 297
Porter, P.S. 57
Posch, M. 79
Postma, D. 193
Potter, K.N. 194
Powers, S.E. 291
Prasher, S.O. 78
Price, Richard E. 144
Priesack, E. 6
Prinz, D. 218
Punthakey, J.F. 93
Putti, M. 198
Quintana, J.O. �81
Rachhpal-Singh 169
Ranjha, A.Y. 20
Rao, K.V.G.K. 250, 251
Rao, P.S.C. 170, 202
Rashmawi, E.A. 52
Ravina, I. 56
Refsgaard, J.C. 157
Reichard, Eric George 75
Rekolainen, S. 79
Requena, A.M. 20
Rhoades, J.D. 98
Ribaudo, M.O. 69
Rijtema, P.E. 195
Ritzi, R.W. Jr 45
Robarts, R.D. 43
Robson, A.J. 11
Roda, F. 246
Rodriguez, B. 236
Rogowski, A.S. 33
Rojas, K.W. 22
Rolston, D.E. 1, 35, 254
Rose, C.W. 141
Rosenthal, W.D. 92
Ross, D. 285
Roth, K. 132
Roy, W.R. 2
Rudra, R.P. 77, 117
Russell, Clifford S. 292
Russo, D. 273, 275
Russo, J. 272
Sabatini, D.A. 90
Sabbagh, G.J. 68, 179, 180
Sadeghi, A.M. 259, 298
Salvich, P.G. 123
Samsel, Theodore B. 50
Sanchez, C.A. 57
Sanders, P. 295
Sardin, M. 172
Sariev, A.L. 181
Sarin, S.C. 186
Sbaa, M. 242
Schalk, C.W. 80
Schenck, C. 192
Schmucker, J.F. 114
Schnitkey, G.D. 112
Schwart, R.B. 114
Schweich, D. 172, 301
Scott, J. C. 31
Scotter, D.R. 184, 302
Scow, K.M. 39
Segerson, K. 3
Selassie, T.G. 243
Selim, H.M. 26, 173, 174, 221
Sequeira, R.A. 290
Setia, P. 105
Seyfried, M.S. 202, 238
Shabtai, R. 176, 280, 281
Shafike, N.G. 185
Shanholtz, V.O. 284
Shani, U. 158
Sharpley, A.N. 248
Shaviv, A. 56
Shaw, R.R. 138
Sheridan, J.M. 327
Shih, S.F. 101, 317, 318
Shimojima, E. 335
Shiono, K. 109
Shirley, E.D. 118
Shirmohammadi, A. 159, 334
Shirmohammadi, Adel,1952- 9
Shnek, M. 56
Shoemaker, L.L.� 159
Shogren, Jason F. 292
Shouse, P.J. 294
Shukurov, M.S. 181
Sichani, S.A. 321
Siegel, D.I. 111
Silva, F.F. da 305
Simanton, J.R. 228, 337
Simmons, D.E. 33
Simmons, K.E. 258
Simunek, J. 164, 165
Sinange, R.K. 103
Singh, S.R. 250, 251
Singh, U. 316
Skaggs, R.W. 163
Skaggs, T.H. 7
Smith, A.E. 217
Smith, C.M. 223
Smith, C.N. 277, 289
Smith, E.G. 54
Smith, M.C. 95
Smith, R.E. 162, 208, 210
Smith, R.T. 45
Smith, S.J. 248
Smith, W.N. 78
Smolen, M.D. 197
Snyder, W.M. 32
Soderstrom, M. 102
Soerens, T.S. 90
Soileau, J.M. 240, 260
Somlyody, L. 137
Sparks, D.L. 127, 295
Spooner, J. 196, 197
Squillace, P.J. 107
Stagnitti, F. 141
Starr, J.L. 84, 298
Steenhuis, T.S. O141
Stein, A. 148
Stewart, D.J. 86
Stewart, M.K. 160
Still, D.A. 318
Stone, J.F. 68
Stone, J.J. 118
Storm, Daniel E. 161
Suarez, D.L. 164, 165
Taff, S.J. 154
Tan, Y.R. 101
Tauer, W. 218
Taylor, C.R. 54
Taylor, D.B. 116, 135, 186
Taylor, J.W. 175, 309
Tedaldi, D.J. 66
Thomas, A.W. 32
Thomas, D.L. 95
Thomas, Daniel L. 9
Thomas, M.V. 99
Thomson, N.R. 203
Thornton, P.K. 316
Thurman, E.M. 107
Tillman, Dottie 144
Tillotson, P.M. 237
Tillotson, W.R. 217
Tilman, R.W. 184
Touchton, J.T. 260
Tracy, J.C. 183
Troch, F.P. de 36
Troch, P.A. 36
Truman, C.C. 61, 213
Tucciarelli, T. 207
Turnbull, A. 146
Uchrin, C.G. 299
United States, Army, Corps of Engineers, Chicago District,
U.S. Army Engineer Waterways Experiment Station 144
United States, Bureau of Land Management, Geological Survey
(U.S.) 227, 286
Van Genuchten, M.T. 7, 51, 136, 140, 172, 250, 251
Van Genuchten, M.Th 84
Van Mullem, J.A. 220
Vinther, F.P. 145
Vogtle, T. 218
Wagenet, R.J. 261, 262
Waggoner, B.L. 98
Wakild, C.R. 330
Walker, W.R. 20
Wallace, R. 305
Wallach, R. 15, 131, 176, 239, 280, 281
Wallis, J.R. 121
Wambua, J. 17
Wang, Y. 154
Ward, A.D. 80
Weaver, R.D. 4
Weber, W.J. Jr 291
Weinberg, M. 328
Wells, W.G. II 314
Weltz, M.A. 228
Wetzstein, M.E. 230
Whistler, J.L. 24
White, R.E. 302
Whitehead, P.G. 11, 18
Whitmore, A.P. 151, 216
Wierenga, P.J. 130, 247, 297
Wight, J.R. 312
Wilcox, B.P. 238, 242
Wilen, J.E. 328
Williams, A.A. 189
Williams, J. 17
Williams, J.R. 180, 194, 248
Williams, R.J. 146
Willis, D. 147
Wohlgemuth, P.M. 314
Wolf, J.K. 33
Wolfaardt, G.M. 43
Wolfe, M.L. 16, 104
Wood, J.C. 34
Woolhiser, D.A. 126
Wright, J.A. 334
Wrobel, L. C. 329
Yamaguchi, T. 1, 254
Yan, J. 187
Yates, M.V. 325
Yates, S.R. 5
Yomota, A. 124
Yoneyama, T. 49
Yoo, K.H. 240, 260
Yoon, K.S. 240, 260
Zanyk, B.N. 43
Zee, S.E.A.T.M. van der 63, 134, 244
Zhang, H. 14
Zhang, W. 62
Zhu, M. 186
Zilliox, L. 192
Subject Index
2,4,5-t 214
2,4-d 92, 217
Absorption 211
Accuracy 1
Acid soils 85
Acidity 224
Activity 197
Adsorption 2, 6, 26, 132, 168, 221, 243, 249, 268, 288, 295
Afforestation 18
Aggregate data 3
Aggregates 6, 82, 155, 172, 204, 205, 323
Agricultural byproducts 108
Agricultural chemicals 15, 19, 25, 43, 54, 131, 167, 176,
196, 215, 230, 232, 256, 277, 280, 281, 283, 296, 311
Agricultural development 192
Agricultural economics 105
Agricultural land 79, 112, 154, 156, 197, 307
Agricultural policy 3, 54, 116, 231
Agricultural pollution 292
Agricultural production 72, 189, 196, 215
Agricultural regions 55
Agricultural sector 3
Agricultural soils 8, 40, 47, 49, 57, 73, 94, 133
Agricultural wastes 99, 117
Air flow 335
Air quality 89
Air temperature 312
Alabama 240, 260
Alachlor 27, 95, 211, 321
Aldicarb 171, 289
Algae 137, 271
Algorithms 44, 100, 163, 231
Alkaline soils 249
Alluvial soils 108, 249
Alternative farming 87
Aluminum oxide 85
Ammonia 306
Ammonium nitrogen 306
Anaerobic digestion 99
Analytical methods 296
Andosols 269
Angling 69
Animal wastes 99, 284
Anion exchange 255
Application date 46, 171
Application methods 112, 159
Application rates 97
Application to land 46, 156
Aquatic communities 271
Aquatic environment 25
Aquifers 26, 45, 66, 96, 193, 235, 250, 251, 253, 291, 299
Arable land 193, 326
Arable soils 244, 258, 279
Arkansas 46, 219, 324
Artemisia tridentata 242
Artificial precipitation 13
Assessment 76, 151, 318
Atrazine 67, 78, 92, 95, 180, 270, 321
Attenuation 76
Autocorrelation 273
Automation 104
Autumn 171
Availability 211
Azinphos-methyl 309
B horizons 85
Bayesian theory 232
Behavior 134
Belgium 36
Beliefs 232
Bentazone 10
Benzene 299
Bibliographies 256
Biochemical oxygen demand 330
Biodegradation 155
Biomass 6
Biomass production 137
Bioremediation 39
Bogs 111
Boron 158
Boundaries 15
Brazil 137
Broadleaved evergreen forests 246
Bromacil 94
Bromide 151, 247, 255, 268, 289, 296
Bromides 95
Bromine 269, 288
Brown earths 149, 150
Buchloe dactyloides 92
Buffering capacity 56
Cabt 87
Cadmium 134, 173, 244
Calcareous soils 56, 158
Calcium 221, 255
Calcium ions 224, 268
Calculation 269
Calibration 25
California 52, 120, 165, 249, 294, 314
Canopy 42, 228
Capacity 218, 296
Capillary fringe 199
Capillary rise 73
Carbaryl 92
Carbofuran 309, 321
Carbon 26, 259
Carbon dioxide 164, 165
Carbonates 45
Carcinoma 142
Case studies 36, 115, 283
Cash flow 114
Catchment hydrology 11, 18, 19, 28, 141, 209, 246, 260
Cation exchange 182, 221, 224, 255, 268
Cation exchange capacity 221, 268
Characteristics 70
Chemical degradation 43
Chemical properties 246
Chemicals 14, 239, 255
China 108
Chloride 255, 302
Chlorides 178
Chlorine 136
Chlorpyrifos 92, 321
Citrus reticulata 108
Clay 33, 140
Clay loam soils 259
Clay soils 41, 178, 280
Clearcutting 18
Climate 28
Climatic factors 10, 19, 42, 70, 97, 175
Climatic zones 194
Cloethocarb 10
Coarse textured soils 136
Coastal plains 159
Coasts 227
Colorado 190
Commercial soil additives 112
Compact soils 268
Comparisons 1, 15, 26, 79, 85, 183, 194, 266
Composts 305
Computer assisted instruction 285
Computer graphics 119, 121
Computer hardware 121
Computer simulation 2, 27, 29, 61, 78, 87, 119, 121, 151,
169, 195, 208, 236, 238, 285, 287, 315, 320
Computer software 40, 48, 118, 119, 121, 138, 211, 236, 310
Computer techniques 12, 29, 68, 104, 272, 307
Computers 223
Concentration 47, 65, 107, 253
Condensation 181
Coniferous forests 37, 193
Connecticut 67, 141
Conservation tillage 240, 260
Constraints 44
Contaminants 26, 43, 88, 140, 170, 282, 323
Contamination 3, 54, 142, 176, 239, 280, 281
Continuous cropping 87, 171
Control methods 232
Convection 1, 84, 269
Cooperative extension service 263
Corn belt of U.S.A. 105
Corn belt states of U.S.A. 87
Cost benefit analysis 215
Cost effectiveness analysis 154
Costa Rica 202
Costs 38, 116, 185, 206, 207, 231, 232
Cotton 290
Crop growth stage 194
Crop management 68, 194, 305
Crop production 46, 91, 108, 112, 179, 316
Crop residues 73, 108
Crop yield 38, 46, 97, 102, 206, 312
Cropping systems 55, 159, 202
Crops 102, 218, 337
Crumbs 157
Crusts 73
Cultivation 159
Culture media 305
Cyanazine 167, 321
Cycling 108, 200, 201
Cynodon dactylon 92, 217
Dairy farms 114
Dairy wastes 114
Data analysis 190
Data banks 12
Data collection 24
Databases 40, 48, 119, 190, 272
Decision making 55, 185, 263, 328
Decomposition 108
Degradation 41, 170, 225
Delta soils 108
Deltas 108, 120
Denitrification 49, 100, 145, 157, 254, 259
Denmark 100, 145
Depth 251, 306
Desertification 103
Design 20
Desorption 2, 39, 56, 249, 281
Deterioration 331
Determination 84, 85, 148, 305
Deterministic models 51, 130, 134, 183, 247
Deuterium 160
Diazinon 92
Dicamba 41, 92
Diffusion 6, 39, 151, 157, 184, 205, 243, 269, 306, 335
Diffusion models 56, 177, 178, 184
Diffusivity 6, 149, 150, 157, 268, 306, 335
Discharge 111, 199, 246
Dispersion 1, 49, 84, 249, 259, 289, 293
Dissolving 249
Distribution 222
Disturbed soils 148, 268
Ditches 108, 296
Diuron 171
Drainage 42, 64, 79, 161, 179, 195, 220, 234, 249, 279, 296,
326, 328, 334
Drainage water 108, 249, 250, 251
Drained conditions 163, 243
Drinking water 60, 142, 216, 311, 331
Dry matter accumulation 108
Dry season 108
Dynamic models 53, 120, 206, 230, 231
Dynamic programming 186
Dynamics 172
Eastern scotland 224
Ecology 111
Econometric models 189
Economic analysis 135
Economic evaluation 55
Economic impact 38, 54, 68, 87, 147, 186, 189, 206
Economics 197
Ecosystems 89
Edaphic factors 228
Effects 72
Effluents 251
Electrical conductivity 243
England 47, 146, 216, 253
Environment 143
Environmental factors 4, 10, 165
Environmental impact 38, 68, 87, 89, 143, 147, 186, 215, 257,
263, 284, 315, 316
Environmental legislation 230, 307
Environmental policy 112, 115
Environmental protection 143, 313, 331
Epidemiology 142
Equations 5, 15, 51, 56, 65, 70, 74, 88, 90, 127, 134, 177,
181, 184, 188, 198, 301, 337
Equilibrium 56, 66, 222, 268, 288
Erodibility 337
Erosion 17, 23, 87, 108, 118, 154, 179, 190, 226, 260, 287,
310, 314, 320, 336
Erosion control 34, 159, 242, 285
Errors 52, 76, 140, 151
Estimated costs 114
Estimates� 79
Estimation 52, 69, 71, 194, 265
Eutrophication 137
Evaluation 151
Evaporation 42, 141, 326, 335
Evapotranspiration 34, 80, 171, 179, 194, 326
Exchangeable cations 221, 222, 268
Exchangeable sodium 221, 243, 255
Experimental design 151
Experimental plots 322
Expert systems 16, 119
Extraction 323
Farm income 206
Farm indebtedness 114
Farm inputs 135, 206, 231
Farm management 186, 206, 328
Farmers' attitudes 232
Farming systems 135, 186
Farmland 23, 191, 195, 234
Farmyard manure 112
Feasibility 55
Federal programs 34, 105, 313
Fenamiphos 283
Fens 111
Fenvalerate 309
Fertigation 91
Fertilizer requirement determination 91, 201, 233
Fertilizer technology 91
Fertilizers 22, 92, 106, 108, 159, 202, 305
Festuca pratensis 326
Field experimentation 210
Field tests 25, 95
Finite element analysis 45, 96
Finland 79
Fish 115
Fishery management 86, 120, 139
Fishing 147
Fixation 85
Flood dams and reservoirs 144
Flood irrigation 94
Flooded rice 306
Flooding 124
Floods 36, 53
Florida 57, 85, 99, 101, 143, 263, 317, 318
Flow 7, 11, 28, 59, 70, 71, 79, 108, 128, 131, 220, 299
Fluids 91
Food chains 86
Food safety 54
Forecasting 36
Forest management 175
Forest soils 37, 197
Forest steppe 53
Forestry 89
Forests 72, 175, 307
Formation 72
France 192
Frequency 79
Fresh water 120
Frost 279
Frozen conditions 279
Fuel tanks 74
Fungicides 106
Furrow irrigation 20
Game theory 230
Geochemistry 66, 100, 193
Geographic information systems 31, 50, 129, 139, 308
Geographical distribution 101, 194, 317
Geographical information systems 263
Geography 103, 272, 284, 307
Geological sedimentation 19, 77, 248, 285
Geology 111
Geomorphology 192
Georgia 61, 95, 175, 180, 189, 230, 277, 327
German federal republic 10, 234
Glacial till soils 37
Gley soils 269
Glycine max 38, 45, 87, 165
Golf courses 106, 217, 315
Golf green soils 106, 217
Gossypium 240
Gossypium hirsutum 260
Grain crops 192
Grape marc 305
Graphic arts 310
Grasses 46
Grassland management 223, 242
Grassland soils 216
Grasslands 192
Grazing effects 200, 201, 223
Green and ampt equation 73, 220
Green manures 81
Greenhouses 181
Ground vegetation 42, 228
Groundwater 3, 28, 30, 54, 61, 63, 66, 95, 98, 101, 102, 105,
111, 123, 143, 180, 183, 185, 197, 199, 207, 215, 231, 237,
246, 249, 252, 277, 299, 309, 311, 317, 321, 325
Groundwater flow 28, 52, 75, 88, 90, 100, 111, 188, 198, 235,
298, 301
Groundwater level 28
Groundwater pollution 2, 14, 16, 20, 29, 33, 35, 38, 43, 44,
45, 49, 68, 74, 88, 89, 90, 106, 107, 116, 128, 135, 142, 143,
155, 159, 183, 185, 188, 189, 191, 192, 193, 195, 198, 203,
206, 212, 214, 230, 231, 235, 245, 253, 256, 274, 283, 291,
295, 296, 297
Groundwater recharge 33, 191, 195, 253
Growth 108
Growth models 208
Growth rate 6
Gully erosion 285
Gypsum 249
Habitats 23, 115
Half life 41
Hapludults 13, 221
Hatcheries 120
Hawaii 76, 106, 283
Health hazards 331
Heat flow 164, 165, 266
Heathland 193
Heavy metals 133, 173
Height 13
Herbage 312
Herbicide residues 27, 67, 92, 94, 106, 107, 217, 270
Heterogeneity 134
High water tables 108
Hill grasslands 62
Histosols 57
Hordeum vulgare 134, 145, 326
Horizons 224
Horizontal flow 58, 259, 275, 298
Humid tropics 202
Hyacinths 99
Hydraulic conductivity 45, 62, 66, 73, 88, 148, 178, 223,
225, 261, 262, 273, 275
Hydraulic resistance 110
Hydraulics 44, 109, 128
Hydrodynamic dispersion 5, 63, 71, 182, 184, 298
Hydrodynamics 235
Hydrogen ions 224
Hydrogeology 50
Hydrologic cycle 286
Hydrologic models 227
Hydrological data 70, 190, 312
Hydrology 9, 64, 72, 80, 104, 111, 113, 121, 187, 208, 259,
324, 334
Hydrolysis 306
Hydromorphic soils 192
Hysteresis 249, 305
Idaho 23, 230
Identification 36
Illinois 73, 82
Immiscible displacement 203
Improvement 12
Inactivation 325
Inceptisols 13
Income 54
Incorporation 280, 306
Indexes 57, 143, 284
India 251
Indiana 313, 321
Indicator plants 271
Indicator species 111, 271
Infiltration 33, 62, 66, 73, 118, 125, 130, 162, 176, 210,
220, 228, 247, 279, 281, 319
Information 232
Information retrieval 12
Information storage 12
Information storage and retrieval systems 139, 278
Information systems 3, 23, 138, 256, 307
Insecticide residues 92, 106
Integrated pest management 315
Intensive cropping 192
Interactions 210
Interception 42, 228
Interface 140, 267
Interrill erosion 13
Iodide 296
Ion exchange 173, 243
Ion transport 259
Ions 246
Iowa 60, 107, 230
Iron oxides 85
Irrigated conditions 201
Irrigated soils 102, 249
Irrigation 55, 66, 68, 97, 123, 147, 249, 305
Irrigation scheduling 41, 102
Irrigation water 91, 102, 108, 235, 249, 328
Japan 124
Kansas 24, 190
Kaolinite 221
Kenya 17, 103
Kinematics 124, 126
Kinetics 26, 56, 84, 85, 118, 125, 127, 152, 172, 173, 243,
281, 288
Labeling 311
Laboratory methods 85, 259, 266, 268, 298, 306
Laboratory tests 128
Lakes 86, 115, 313
Land diversion 313
Land management 28, 138, 154, 285, 313
Land types 285, 307
Land use 154, 192, 193, 197, 285, 307
Landsat 24, 318
Lasers 13
Law 114
Law enforcement 331
Lawns and turf 315
Layered soils 125, 136, 140, 267
Leachates 33, 106, 231
Leaching 10, 20, 27, 29, 38, 41, 47, 51, 57, 61, 63, 67, 76,
78, 81, 94, 95, 102, 105, 106, 123, 133, 134, 140, 143, 145,
148, 151, 153, 168, 171, 174, 175, 178, 180, 184, 194, 200,
201, 202, 216, 217, 222, 229, 233, 237, 243, 245, 249, 252,
254, 255, 258, 259, 263, 270, 273, 274, 289, 299, 302, 309,
316, 321
Leakage 74
Legal liability 230
Legumes 186
Length 84
Leys 326
Linear models 132, 261, 262
Linuron 152
Liquid fertilizers 91
Literature reviews 89, 99, 174, 200, 201, 300
Livestock enterprises 112
Livestock numbers 112
Loam soils 1, 145
Lolium multiflorum 145
Long term experiments 66, 145
Losses 115, 156, 159
Losses from soil 81, 117, 213, 245, 260, 302
Losses from soil systems 20, 46, 57, 61, 108, 145, 169, 202,
211, 216, 223, 228, 259, 304, 306, 320, 322
Louisiana 179, 180, 221
Lowland areas 269
Lysimeters 10
Lysimetry 153
Macropore flow 37, 80, 177, 178, 261, 262
Macropores 22, 37, 177, 204, 261, 262, 269
Madhya pradesh 55
Magnesium 221, 222, 255
Maize 112, 192
Mali 209
Management 12, 40, 91, 137
Manures 99
Mapping 23
Maps 102
Marine resources 139
Markets 328
Maryland 159, 259
Mass transfer 291
Massachusetts 106
Mathematical models 1, 3, 4, 5, 6, 7, 13, 15, 26, 32, 35, 39,
49, 51, 52, 53, 56, 58, 60, 62, 72, 73, 79, 84, 85, 91, 92,
94, 96, 97, 98, 99, 100, 106, 112, 114, 115, 124, 126, 128,
131, 135, 136, 140, 141, 142, 147, 149, 150, 157, 158, 160,
162, 163, 164, 165, 170, 171, 172, 173, 174, 176, 177, 178,
180, 181, 182, 185, 188, 198, 199, 205, 210, 216, 217, 221,
225, 232, 235, 239, 240, 241, 242, 244, 246, 248, 249, 250,
251, 252, 254, 255, 257, 259, 266, 267, 268, 269, 270, 271,
274, 276, 277, 280, 281, 288, 289, 291, 293, 294, 295, 299,
300, 301, 302, 305, 306, 319, 323, 324, 335
Mathematics 13, 74, 90, 151
Matric potential 266
McCook Reservoir (Ill.) 144
Measurement 13, 47, 145, 149, 150, 151, 153, 160, 207, 209,
215, 247, 266, 269, 270, 285
Mecoprop 47
Medicago sativa 87
Mediterranean climate 246
Meltwater 37, 53
Metals 295
Meteorological factors 194, 208, 252, 326
Methane 323
Methane production 99
Methodology 38, 168, 194, 237, 263
Metolachlor 67, 180, 270, 289
Metribuzin 27
Michigan 29, 115
Microbial activities 168
Microbial contamination 282
Microbial degradation 2, 6, 39, 43
Microcomputers 119, 285
Microeconomic analysis 3, 87
Microeconomics 4
Mineralization 81, 233, 258
Minnesota 107, 154, 230, 313
Mississippi 226
Missouri 165
Mixtures 305
Models 36, 40, 42, 43, 47, 54, 57, 65, 66, 67, 69, 70, 102,
103, 107, 108, 117, 125, 137, 143, 146, 190, 192, 193, 196,
197, 203, 212, 215, 218, 220, 222, 253, 267, 272, 282, 284,
296, 297, 303, 307, 310, 313, 325, 330
Mole drainage 302
Monitoring 47, 79, 91
Montana 220
Monte carlo method 63
Mounds 111
Mountain areas 159
Movement 282
Movement in soil 6, 14, 22, 26, 33, 43, 45, 57, 68, 74, 76,
84, 85, 91, 94, 96, 125, 132, 140, 151, 152, 153, 158, 174,
182, 183, 184, 194, 208, 214, 221, 222, 243, 249, 250, 251,
254, 255, 259, 267, 268, 269, 283, 288, 291, 296, 297, 300,
325
Movement to roots 76
Mulches 17
Multivariate analysis 70
Musa paradisiaca 108
Nebraska 110, 190, 191
Netherlands 148, 195, 244, 252
New Jersey 295, 299
New Mexico 130, 247
New South Wales 70, 123
New York 111
New Zealand 160, 200, 201, 223
Nitrate 49, 81, 100, 136, 142, 148, 191, 195, 234, 259
Nitrate fertilizers 142, 191, 195, 234
Nitrate nitrogen 60, 151, 216, 258, 259
Nitrates 29, 45, 116, 167, 192, 193, 206, 231, 233, 253
Nitrification 254, 258
Nitrogen 46, 72, 81, 91, 106, 108, 145, 156, 159, 169, 194,
216, 254, 258, 260
Nitrogen balance 81, 258
Nitrogen fertilizers 16, 60, 186, 231, 233, 316, 326
Nontarget effects 89
Norflurazon 27
North Carolina 13, 38, 330
Northern scotland 224
Nutrient availability 56, 81
Nutrient content 108
Nutrient intake 200, 201
Nutrient requirements 91
Nutrient sources 259
Nutrient uptake 56, 81, 91
Nutrients 72, 108, 202, 212
Objectives 86
Ohio 45
Oklahoma 68, 113, 187, 248, 324
On line 36
Ontario 117
Optimization 115
Optimization methods 44
Oregon 206
Organic compounds 2, 6, 74, 90, 155, 188
Organic fertilizers 156
Organic matter 26, 108
Organic wastes 156
Organochlorine insecticides 229
Oryza sativa 108, 269, 306
Overland flow 15, 77, 107, 124, 126, 176, 199, 210, 239, 280,
281
Oxidation 100, 249
Oxygen consumption 157
Oxygen transport 157
Paddy soils 268, 269, 306
Pans 268
Participation 69
Particle size 65, 335
Particle size distribution 204, 205
Particle velocity 205
Pastures 200, 201
Peatlands 111
Pennsylvania 258
Percolation 34, 61, 194
Permeability 58, 73
Permethrin 309
Persistence 41, 171, 274
Pest control 68
Pesticide residues 10, 54, 106, 146, 214, 289
Pesticides 20, 22, 25, 30, 38, 61, 63, 68, 76, 87, 89, 95,
105, 115, 143, 153, 175, 189, 211, 212, 213, 237, 245, 252,
263, 274, 311, 315
Petroleum 74, 128, 299
Petroleum hydrocarbons 74
Ph 91, 306
Phosphates 167
Phosphorus 46, 56, 57, 72, 79, 85, 112, 200, 260
Phosphorus pentoxide 108
Phthalates 259
Physical models 37, 53, 283, 326
Physicochemical properties 51, 63, 134, 221, 249, 294
Phytoplankton 271
Picea abies 37
Picloram 288
Pig farming 112
Pinus sylvestris 37
Pinus taeda 175
Placement 44
Plains 159
Planning 197
Plant communities 111, 190
Plant density 62
Plant development 326
Plant nutrition 91
Plant water relations 8
Plants 252
Plastic cladding 181
Plowing 216
Podzolic soils 255
Pollutants 2, 14, 16, 39, 90, 96, 117, 147, 167, 183, 188,
198, 208, 210, 235, 253, 257, 274, 291, 295, 297, 301, 325
Polluted soils 39, 74, 244
Pollution 23, 79, 115, 208, 232, 272, 287, 316
Pollution control 112, 231
Populations 120
Pore size distribution 276
Pore volume 268, 269
Pores 6, 221, 268
Porosity 148, 172, 178, 204, 205
Porous media 51
Pot culture 305
Potassium 108, 221, 222, 255
Potassium bromide 184
Potassium chloride 302
Potassium nitrate 259
Poultry manure 46, 219
Practice 12, 159
Prairies 228
Precipitation 37, 41, 60, 95, 171, 187, 220, 238, 312, 326
Precipitation (Meteorology) 286
Prediction 7, 12, 14, 25, 56, 65, 66, 71, 81, 96, 130, 141,
163, 164, 165, 169, 170, 175, 176, 178, 203, 209, 220, 221,
222, 223, 224, 228, 238, 242, 247, 248, 250, 251, 253, 260,
273, 274, 280, 281, 289, 293, 294, 296, 297, 304, 309, 312,
322, 336, 337
Prevention 29, 296
Probabilistic models 53, 71, 183
Probabilities 161
Probability 32
Problem solving 44, 187, 192
Production 164, 165
Profiles 67, 76, 134, 140, 148, 175, 239, 258, 289
Profit functions 189
Profitability 38, 114, 135
Program development 12
Program evaluation 313
Programming 187
Public agencies 331
Public health 143
Pulp and paper industry 330
Pulp mill effluent 330
Pumps 44
Pyrites 100
Qualitative techniques 140
Quality standards 331
Quantitative analysis 49, 120, 128
Quantitative techniques 13
Quebec 320
Rain 11, 14, 18, 32, 36, 42, 53, 55, 62, 64, 70, 73, 76, 77,
108, 113, 117, 125, 126, 160, 162, 167, 176, 199, 209, 210,
213, 226, 228, 241, 265, 281, 303, 319, 324, 327
Rainy season 108
Random sampling 88
Rangeland soils 319
Rangelands 190, 228, 238, 242, 312, 319, 337
Ranking 143, 272, 284
Ratios 243
Recharge 66, 123
Reclamation 124, 243
Redistribution 162, 247
Redox reactions 100
Reduction 100, 193
Reflectance 65
Regional planning 129
Registration 30, 143
Regression analysis 229, 322
Regulations 120, 189, 230, 231, 232, 311
Relationships 176
Reliability 232
Remote sensing 24, 65, 103, 138, 209
Removal 72
Replication 151
Reserved areas 34
Reservoirs �137, 144
Respiration 164
Responses 65
Retention 173
Returns 38, 112
Reviews 197
Rhizosphere 149, 150, 169
Rill erosion 337
Riparian vegetation 23
Risk 25, 55, 106, 114, 142, 234, 235, 263
River water 52, 107, 257
Rivers 147, 234, 236, 330
Root exudates 149, 150
Root systems 91
Root zone flux 22, 212
Roots 108, 268, 269
Rotations 45, 87
Rsfsr 72
Runoff 11, 17, 18, 19, 25, 28, 32, 34, 36, 37, 62, 64, 68,
70, 73, 77, 79, 80, 82, 87, 95, 105, 106, 110, 112, 113, 118,
124, 126, 141, 162, 167, 176, 179, 180, 181, 187, 190, 195,
199, 211, 213, 219, 220, 223, 226, 227, 228, 234, 238, 239,
240, 241, 242, 248, 260, 263, 264, 265, 280, 281, 285, 303,
309, 310, 312, 319, 320, 322, 324, 326, 327
Runoff farming 218
Runoff irrigation 218
Runoff water 15, 42, 46, 53, 55, 72, 92, 108, 125, 131, 156,
209, 216, 239, 282, 313
Rural areas 70
Saccharum officinarum 108
Saline sodic soils 243
Saline soils 243
Saline water 66, 97, 102, 235
Salinity 52, 91, 123
Salmon 120
Salts in soil 243, 249
Salvage felling and logging 314
Samples 270
Sampling 79, 102, 277
Sand 140, 221, 323
Sandy loam soils 27, 259, 266, 273
Sandy soils 85, 134, 145, 171, 252
Satellite imagery 103, 209
Saturated conditions 152, 243, 249
Saturated flow 51
Saturated hydraulic conductivity 37, 59, 130, 141, 276, 305,
319
Scotland 11, 18
Screening 284
Seasonal variation 60, 246, 257
Sediment 26, 65, 72, 108, 167, 285, 314, 320
Sediment transport 109, 264
Sediment yield 82, 154, 226
Seed orchards 309
Seepage 80, 141, 183
Selection 102
Selection methods 307
Selenium 168, 249
Semiarid soils 130, 247
Semiarid zones 17, 55, 209
Sewage 137, 329
Sewage effluent 307
Sewage effluent disposal 307
Sheep 200, 201
Silt loam soils 184, 280, 288, 302, 306
Silviculture O89
Simazine 47, 152
Simulation 58, 100, 120, 162, 163, 170, 183, 199, 209, 213,
224, 251, 259, 261, 262, 269, 275, 326
Simulation models 1, 8, 10, 11, 12, 14, 17, 18, 19, 20, 22,
24, 25, 27, 28, 30, 33, 34, 37, 38, 41, 44, 45, 55, 64, 68,
74, 76, 77, 80, 81, 82, 85, 86, 87, 89, 92, 95, 104, 106, 110,
111, 113, 118, 119, 121, 123, 127, 128, 142, 148, 150, 151,
152, 153, 154, 155, 156, 158, 159, 164, 165, 167, 168, 169,
173, 175, 179, 182, 186, 187, 191, 194, 195, 199, 200, 201,
202, 204, 206, 207, 208, 211, 213, 217, 219, 223, 224, 226,
228, 233, 236, 237, 242, 245, 256, 257, 258, 260, 263, 265,
266, 268, 279, 283, 285, 289, 290, 298, 302, 304, 309, 311,
312, 316, 319, 321, 322, 327, 328, 334
Site factors 3, 228, 284, 307
Site selection 218
Size 13, 157
Slope 62
Slopes 37, 141, 226
Sloping land 124, 125, 176, 281
Snow 279
Social values 307
Sodium 243, 255
Soil 102, 134, 155, 218, 229, 283, 295, 337
Soil air 157, 168
Soil amendments 219
Soil analysis 84, 152, 254
Soil biology 164
Soil boundaries 13, 140, 267
Soil chemistry 57, 66, 127, 164, 168, 174, 224, 258, 300
Soil compaction 269
Soil conservation 17, 34, 105, 138, 241, 285
Soil depth 8, 27, 37, 59, 108, 141, 210, 225, 249, 255, 265,
279, 280, 289
Soil erosion 161, 264
Soil fertility 17, 202, 233
Soil flora 6, 39, 168
Soil management 306
Soil morphological features 171
Soil morphology 148
Soil movement 115
Soil organic matter 85, 148, 216, 244
Soil ph 244, 295
Soil physical properties 141, 307, 326
Soil physics 56, 177, 178
Soil pollution 2, 14, 35, 39, 43, 67, 74, 76, 90, 112, 128,
134, 155, 156, 159, 188, 193, 203, 270, 291, 295, 297, 301,
323
Soil pore system 6, 172, 279, 288, 298
Soil properties 10, 40, 47, 57, 78, 82, 95, 117, 252, 263,
273 Soil salinity 97, 102, 251
Soil solution 1, 6, 15, 56, 84, 91, 221, 222, 239, 244, 255
Soil sterilization 168
Soil structure 148
Soil surveys 148
Soil temperature 37, 41, 145, 153, 171, 266, 279, 325
Soil testing 1, 151
Soil texture 8, 20, 148, 319
Soil types 65, 192, 228, 293, 294, 335
Soil types (genetic) 173
Soil variability 130, 136, 148, 194, 244, 247, 307
Soil water 22, 49, 62, 71, 95, 130, 141, 145, 153, 157, 160,
176, 194, 221, 246, 247, 266, 275, 288, 298, 326
Soil water balance 55, 141, 163, 194, 202, 326
Soil water content 1, 13, 73, 91, 148, 157, 162, 183, 222,
261, 262, 265, 266, 279, 281, 325
Soil water movement 1, 8, 41, 74, 85, 90, 136, 162, 175, 184,
188, 198, 199, 214, 243, 254, 255, 266, 267, 288, 289, 301
Soil water potential 305
Soil water regimes 325
Soil water retention 37, 136, 148, 266, 273, 305
Soil zonation 225
Solar radiation 312
Solubility 56, 133
Solutes 1, 5, 6, 7, 8, 14, 49, 51, 58, 59, 71, 84, 98, 130,
132, 140, 149, 150, 157, 163, 170, 172, 174, 176, 177, 178,
182, 184, 199, 210, 225, 243, 246, 247, 249, 250, 251, 267,
268, 275, 276, 281, 283, 293, 294, 297, 300, 302
Solvents 229
Sorghum bicolor 97
Sorption 39, 56, 57, 63, 85, 149, 150, 152, 170, 173, 229,
244, 259, 270, 281, 289, 306
Sorption isotherms 26, 85, 150, 244, 288
South Dakota 212
Southern plains states of U.S.A. 241
Southern states of U.S.A. 54, 89, 309
Soybeans 55
Spacing 251
Spain 236, 246
Spatial distribution 3, 6, 33, 91, 100, 102, 164, 165, 221,
249, 266, 271
Spatial variation 13, 33, 63, 71, 148, 194, 244, 265, 266,
273, 275, 276, 279
Species diversity 89
Splash erosion 77
Spodosols 85, 244
Spread 296
Spreading 267
Spring 171
Standards 295
Statistical analysis 151, 273
Statistical data 151
Statistical methods 267
Steady flow 165, 297
Steppes 228
Stochastic models 59, 63, 88, 116, 207, 234, 273, 275, 312
Stochastic programming 116
Storage 194, 258
Storms 162, 220, 226, 248
Straw 99
Stream flow 18, 28, 60, 113, 160, 246, 324
Streams 82, 224, 246
Strontium 268
Subsoil 33, 221, 265, 269
Substrates 6
Subsurface barriers 140
Subsurface drainage 251, 327
Subsurface irrigation 334
Subsurface layers 5, 85, 199, 291, 335
Subsurface runoff 40
Subtropics 108, 143
Sulfur 201
Superphosphates 200, 201
Supply response 189
Surface layers 13, 73, 131, 225, 283
Surface roughness 13, 110
Surface water 15, 28, 46, 106, 111, 197, 210, 215, 241, 309
Survival 114
Susceptibility 16
Suspensions 65
Sustainability 108, 316
Swamps 111
Sweden 37, 326
Systems 331
Systems approach 283
Taiwan 303
Taxes 189, 206, 232
Teaching methods 285
Technology 4
Technology transfer 138
Temperature 246, 306
Temporal variation 91, 108, 151, 271
Terbufos 211
Terrain 287
Tests 296
Texas 16, 28, 66, 114, 190, 248, 257
Thematic mapper 24
Theory 127, 270, 290
Thermal conductivity 266
Thermal diffusivity 266
Thermodynamics 66
Thickness 148
Tile drainage 80, 250, 251
Tillage 13, 17, 73, 82, 110, 159, 240, 260, 322
Time 172
Time lag 249
Timing 46
Toluene 299, 323
Topography 13, 126, 307
Topsoil 178, 265
Toxicity 143
Toxicology 263
Tracers 289, 296
Traditional farming 240
Transformation 63, 156, 170, 293
Transient flow 8, 51, 165, 297
Transpiration 326
Transport 88
Transport processes 1, 2, 5, 6, 7, 8, 13, 15, 26, 39, 49, 51,
56, 58, 59, 71, 74, 79, 84, 85, 90, 91, 94, 98, 100, 127, 130,
131, 132, 136, 149, 150, 152, 157, 158, 160, 163, 164, 165,
168, 169, 170, 172, 173, 174, 176, 177, 182, 183, 188, 193,
198, 199, 204, 205, 208, 210, 221, 225, 235, 239, 244, 247,
249, 250, 254, 261, 262, 266, 267, 268, 269, 270, 275, 276,
281, 283, 288, 293, 294, 298, 300, 301, 306, 323, 325, 335
Transverse distribution 58
Trends 120
Trichloroethylene 2
Trickle irrigation 91
Tritiated water 184
Triticum aestivum 97, 165, 233
Triticum turgidum 97
Tritium 247
Tunisia 102
Turbidity 65
Turbulent flow 335
Two dimensional flow 58
U.S.A. 4, 12, 34, 183, 194, 328, 331
U.S.S.R.in europe 53, 72
Uncertainty 14
Underground storage 74
Undisturbed sampling 259
Unfrozen water 279
Universal soil loss equation 285, 336
Unsaturated flow 96, 136, 157, 163, 199, 225, 273, 275, 276,
297
Unsaturated hydraulic conductivity 305
Upland areas 110, 124
Uptake 63, 133, 134, 252, 258
Upward movement 111
Urban areas 197
Urea 306
Urea fertilizers 169
Usage 38, 215, 231
Usda 12, 105, 138
Uses 189
Utah 20
Validity 244, 290, 327
Vapor 2, 323
Variance 267
Variation 14, 151
Vegetation 28, 111, 190
Velocity 199, 259, 269, 288, 289, 298
Vermont 230, 307
Vertical movement 275, 289, 293, 309
Victoria 70, 235
Virginia 116, 135, 186, 284
Viruses 325
Volatile compounds 35
Volatilization 2, 169, 306
Volcanic ash 305
Wales 216
Washington 147
Waste disposal 46, 99
Waste disposal sites 307
Waste treatment 137
Waste water 66
Waste water treatment 236
Wastes 185
Water 31, 83, 102, 166, 199, 292, 329, 332
Water allocation 328
Water balance 153, 327
Water conservation 32
Water content 246
Water distribution 199, 220, 331
Water erosion 12, 34, 82, 228, 241, 242, 285, 304, 322, 336,
337
Water flow 22, 37, 48, 49, 51, 110, 120, 130, 141, 160, 164,
165, 171, 208, 247, 250, 261, 262, 275, 279
Water harvesting 55, 209
Water holding capacity 141
Water management 20, 28, 48, 52, 80, 98, 101, 115, 119, 120,
121, 138, 185, 207, 236, 334
Water policy 4, 69, 328
Water pollution 3, 24, 47, 57, 60, 61, 69, 72, 78, 87, 106,
107, 146, 147, 154, 156, 180, 195, 196, 197, 234, 236, 252,
257, 258, 260, 263, 277, 284, 321
Water purification 137, 147
Water quality 4, 9, 19, 21, 24, 30, 40, 46, 48, 52, 54, 60,
65, 66, 69, 86, 89, 97, 98, 105, 108, 109, 111, 114, 120, 122,
135, 137, 144, 147, 154, 163, 190, 194, 197, 207, 215, 219,
223, 224, 231, 234, 236, 241, 245, 246, 251, 257, 260, 263,
271, 277, 278, 287, 308, 311, 313, 317, 318, 328, 329, 330,
331, 332, 333, 334
Water quality management 83, 122, 292
Water recreation 147
Water relations 55
Water requirements 218
Water resources 113, 119, 120, 121, 137, 197
Water storage 218
Water supply 185
Water table 52, 80, 111, 163, 179, 203, 251, 334
Water transport 282
Water uptake 171
Water use efficiency 328
Water vapor 266, 335
Water yield 70, 141
Water, Underground 75, 308
Watershed management 129, 139, 187, 259
Watersheds 11, 18, 23, 24, 28, 32, 53, 64, 70, 72, 89, 113,
115, 126, 141, 154, 160, 175, 179, 190, 209, 224, 226, 238,
241, 246, 265, 272, 286, 303, 310, 320, 324, 327
Weather 175
Weather data 53, 312
Weed competition 38
Weed control 38
Wells 101, 102, 253, 317
West Africa 218
Wetlands 313, 318
Wetting front 73, 130
Wheat 55
Wind 335
Wisconsin 296, 313
Wyoming 190
Xylene 299
Yield forecasting 312
Yield losses 102
Yield response functions 55
Zea mays 45, 61, 87, 97, 165, 171, 179, 252, 322
Zoning 53
Zooplankton 271
***************************************************************
SEARCH STRATEGY
Set Items Description
S1 40216 (MODEL?)/TI,DE,ID
S2 13239 (POLLUTION(2N)AGRICULTUR? OR
AGRICULTURAL()WASTE? OR WATER()QUALITY OR
GROUNDWATER()POLLUTION OR
TRANSPORT()PROCESSES OR LEACHING OR
RUNOFF)/TI,DE,ID
S3 1606 S1 AND S2
S4 1333 (ANSWERS OR CNS OR STORM OR ARM OR
CREAMS)/TI,DE,ID
S5 42707 (MODEL? OR SIMULATION? ?)/TI,DE,ID
S6 124 S4 AND S5
S7 98 (CPM OR GLEAMS OR NTRM OR PRZM OR WEPP OR
AGNPS OR HSPF OR NPS OR SWAM OR SWMM OR
SWRRB)/TI
S8 356 (GIS OR GEOGRAPHIC()INFORMATION()SYSTEM?
?)/TI,DE,ID
S9 73680 SH=(P200 OR WOOO OR J800)
S10 76 S8 AND S9
S11 1788 S3 OR S6 OR S7 OR S10
S12 394 S11 AND (PY=(1991 OR 1992 OR 1993)
***************************************************************
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national role, NAL supplies copies of agricultural materials not
found elsewhere. Filling requests for materials readily
available from other sources diverts NAL's resources and
diminishes its ability to serve as a national source for
agricultural and agriculturally related materials. Therefore,
NAL is viewed as a library of last resort.
Submit requests to state/region/network sources prior to sending
to NAL. Within the United States, possible sources are public
libraries, land-grant university libraries or other large
research libraries within a state. In other countries submit
requests to major university, national or provincial
institutions. If the needed publications are not available from
these sources, submit requests to NAL with a statement indicating
their non-availability.
REQUESTS -- Submit on the American Library Association (ALA) or
the International Federation of Library Associations and
Institutions (IFLA) interlibrary loan form or via electronic mail
or telefacsimile (see over for more details). Include the
complete name of the person authorizing the request on each form;
the standard bibliographic source which lists the title as owned
by NAL; and the call number if the citation is from an NAL
database (CAIN/AGRICOLA, "Bibliography of Agriculture," or the
NAL catalog).
LOAN SERVICE -- Materials in the NAL collection are loaned only
to U.S. libraries. The loan period is one month.
The following materials are not available for loan: serials
(except for USDA serials); rare, reference, and reserve books;
microforms; and proceedings of conferences or symposia.
Photocopy or microform of the non-circulating publications is
supplied automatically (as described below) when the requesting
organization indicates that photocopy is acceptable on the loan
form.
AUDIOVISUALS (AVs) -- Order at least 3-4 weeks before the
intended show date. Give show date and alternate show date when
requesting specific titles. Request specific format needed if
more than one format is given in the citation.
DOCUMENT DELIVERY SERVICE -- Submit a separate completed
interlibrary loan form for each article required. Indicate
willingness to pay charges on the form and compliance with
copyright law or include a statement that the article is for
"research purposes only." Requests are not processed without
these statements.
CHARGES:
* Photocopy, hard copy of microfilm and microfiche - $5.00 for
the first 10 pages or fraction copied from a single article
or publication. $3.00 for each additional 10 pages or
fraction.
* Duplication of NAL-owned microfilm - $10.00 per reel.
* Duplication of NAL-owned microfiche - $5.00 for the first
fiche and $ .50 for each additional fiche per title.
BILLING - Charges include postage and handling, and are subject
to change. Invoices are issued quarterly by the National
Technical Information Service (NTIS), 5285 Port Royal Road,
Springfield, VA 22161. Establishing a deposit account with NTIS
is encouraged. DO NOT SEND PREPAYMENT.
Send Requests to:
USDA, National Agricultural Library
Document Delivery Services Branch, ILL, PhotoLab
10301 Baltimore Blvd., NAL Bldg.
Beltsville, Maryland 20705-2351
Contact the Head, Document Delivery Services Branch in writing or
by calling (301) 504-5755 with questions or comments about this
policy.
3) DOCUMENT DELIVERY SERVICES AVAILABLE TO FOREIGN LIBRARIES,
INFORMATION CENTERS AND COMMERCIAL ORGANIZATIONS.
The National Agricultural Library (NAL) accepts requests from
libraries and other organizations in accordance with the national
and international interlibrary loan code and guidelines.
In its national role, NAL supplies copies of agricultural
materials not found elsewhere. Filling requests for materials
readily available from other sources diverts NAL's resources and
diminishes its ability to serve as a national source for
agricultural and agriculturally related materials. Therefore,
NAL is viewed as a library of last resort.
Submit requests to major university libraries, national or
provincial institutions or network sources prior to sending
requests to NAL. If the needed publications are not available
from these sources, submit requests to NAL with a statement
indicating their non-availability.
AGLINET -- Requesters in countries with an AGLINET library are
encouraged to make full use of that library and its networking
capabilities. As an AGLINET participant, NAL provides free
document delivery service for materials published in the United
States to other AGLINET participants.
REQUESTS -- Submit requests on the American Library Association
(ALA) or the International Federation of Library Associations and
Institutions (IFLA) interlibrary loan form or via electronic mail
or telefacsimile (see over for more details). Include the
complete name of the person authorizing the request on each form;
the standard bibliographic source which lists the title as owned
by NAL; and the call number if the citation is from an NAL
database(CAIN/AGRICOLA, "Bibliography of Agriculture", or the NAL
catalog).
DOCUMENT DELIVERY SERVICE -- Submit a separate completed
interlibrary loan form for each article requested. Indicate
willingness to pay charges on the form, and compliance with
copyright law or include a statement that the article is for
"research purposes only". Requests cannot be processed without
these statements.
CHARGES:
* Photocopy, hard copy of microfilm and microfiche - $5.00 for
the first 10 pages or fraction copied from a single article
or publication. $3.00 for each additional 10 pages or
fraction.
* Duplication of NAL-owned microfilm - $10.00 per reel.
* Duplication of NAL-owned microfiche - $5.00 for the first
fiche and $ .50 for each additional fiche per title.
BILLING - Charges include postage and handling, and are subject
to change. Invoices are issued quarterly by the National
Technical Information Service (NTIS), 5285 Port Royal Road,
Springfield, VA 22161. Establishing deposit account with NTIS is
encouraged. Annual billing is available to foreign institutions
on request by contacting NAL at the address below. DO NOT SEND
PREPAYMENT.
Send Requests to:
USDA, National Agricultural Library
Document Delivery Services Branch, ILL, PhotoLab
10301 Baltimore Blvd., NAL Bldg.
Beltsville, Maryland 20705-2351
Contact the Head, Document Delivery Services Branch at (301)
504-5755 with questions or comments about this policy.
ELECTRONIC MAIL ACCESS FOR INTERLIBRARY LOAN (ILL) REQUESTS
June 1993
The National Agricultural Library (NAL), Document Delivery
Services Branch accepts ILL requests from libraries via several
electronic services. All requests must comply with established
routing and referral policies and procedures. The transmitting
library will pay all fees incurred during the creation of
requests and communication with NAL. A sample format for
ILL requests is printed below along with a list of the required
data/format elements.
ELECTRONIC MAIL - (Sample form below)
SYSTEM ADDRESS CODE
====================================================
INTERNET. . . . . LENDING@NALUSDA.GOV
EASYLINK. . . . . 62031265
ONTYME. . . . . . NAL/LB
TWX/TELEX . . . . Number is 710-828-0506 NAL LEND.
This number may only be used for
ILL requests.
FTS2000 . . . . . A12NALLEND
OCLC . . . . . . NAL's symbol AGL need only be entered
once, but it must be the last entry in
the Lender string. Requests from USDA
and Federal libraries may contain AGL
anywhere in the Lender String.
SAMPLE ELECTRONIC MAIL REQUEST
=================================================================
| AG University/NAL ILLRQ 231 4/1/93 NEED BY: 6/1/93
|
|
|
| Interlibrary Loan Department
|
| Agriculture University
|
| Heartland, IA 56789
|
|
|
| Dr. Smith Faculty Ag School
|
|
|
| Canadian Journal of Soil Science 1988 v 68(1): 17-27
|
| DeJong, R. Comparison of two soil-water models under
|
| semi-arid growing conditions
|
| Ver: AGRICOLA
|
| Remarks: Not available at IU or in region.
|
| NAL CA: 56.8 C162
|
|
|
| Auth: C. Johnson CCL Maxcost: $15.00
|
|
|
| MORE
|
|
|
=================================================================
TELEFACSIMILE - Telephone number is 301-504-5675. NAL accepts
ILL requests via telefacsimile. Requests should be created on
standard ILL forms and then faxed to NAL. NAL does not fill
requests via Fax at this time.
REQUIRED DATA ELEMENTS/FORMAT
1. Borrower's address must be in block format with at least two
blank lines above and below so form may be used in
window envelopes.
2. Provide complete citation including verification, etc.
3. Provide authorizing official's name (request will be
rejected if not included).
4. Include statement of copyright compliance if applicable.
5. Indicate willingness to pay applicable charges.
6. Include NAL call number if available. Contact the Document
Delivery Services Branch at (301) 504-6503 if additional
information is required.
Return to the Water Quality Information Center at the National Agricultural
Library.
Last update: September 2, 1998
The URL of this page is http://www.nal.usda.gov/wqic/Bibliographies/qb9406.html
J. R. Makuch /USDA-ARS-NAL-WQIC/
jmakuch@nal.usda.gov