Project Summary Sheet

Study Title: Linking a conceptual karst hydrogeologic model of the Biscayne aquifer to ground-water flow simulations from Everglades National Park to Biscayne National Park-Phase 1
Study Start Date: Oct. 1, 2005 Study End Date: Sept. 30, 2009
Web Sites: See http://sofia.usgs.gov/people/cunningham.html for information on principal investigator.
Location (Subregions, Counties, Park or Refuge): SE Florida, Miami-Dade County, includes ENP & BNP
Funding Source: USGS Greater Everglades Priority Ecosystems Science (GE PES) and ENP Critical Ecosystems Studies Initiative (CESI)
Other Complementary Funding Source: None
Funding History: FY06, FY07
Principal Investigator: Kevin J. Cunningham
Study Personnel: Melinda A. Wolfert, Christian D. Langevin, Michael A. Wacker, G. Lynn Wingard, Edward Robinson, Joann F. Dixon, Lee J. Florea, Michael C. Sukop, Pedro F. Alvarez, Haibo Huang, W. Barclay Shoemaker, H. Allen Curran, Cameron Walker
Supporting Organizations: USGS Mendenhall Postdoctoral Program
Associated / Linked Studies: Biscayne Bay Coastal Wetlands Project, L31N/L30 Seepage Management Pilot Project, Everglades National Park Seepage Management Project, Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement Project, Lake Belt In-Ground Reservoir Technology Pilot Project, and Landscape-Scale Science Needed to Support Multiple CERP Projects.

Overview & Objective: Research is needed to determine how planned CERP seepage control actions within the triple-porosity karstic Biscayne aquifer in the general area of Northeast Shark Slough will affect ground-water flows and recharge between the Everglades wetlands and Biscayne Bay. A fundamental problem in the simulation of karst ground-water flow and solute transport is how best to represent aquifer heterogeneity as defined by the spatial distribution of porosity, permeability, and storage. The triple porosity of the Biscayne aquifer is principally: (1) matrix of interparticle and separate-vug porosity, providing much of the storage and, under dynamic conditions, diffuse-carbonate flow; (2) touching-vug porosity creating stratiform ground-water flow passageways; and (3) less common conduit porosity composed mainly of bedding plane vugs, thin solution pipes, and cavernous vugs. The objectives of this project are to: (1) build on the Lake Belt area hydrogeologic framework (recently completed by the principal investigator), mainly using cyclostratigraphic and borehole geophysical methods to map porosity types and develop the triple-porosity karst framework between the Everglades wetlands and Biscayne Bay and (2) develop procedures for numerical simulation of ground-water flow within the Biscayne aquifer multi-porosity system. Technologies developed in this program are novel and will be applicable to integrated science approaches needed by decision makers for adaptive management of ecosystems.

Status: (1) Task 1: Drilled 8 test coreholes. (2) Task 2: Collected and processed geophysical logs for the 8 test coreholes. (3) Task 3: (a) Interpretation of cyclostratigraphy and hydrostratigraphy and development of a new karst hydrogeologic framework for the 8 new coreholes between ENP and BNP is in progress. (b) Improved understanding of relation of macroporous units of the Biscayne aquifer and cyclostratigraphy and ichnology. (c) Produced 3-D computer-aided tomographic (CT) renderings of solid and porous portions of 6 very-highly permeable limestone samples that represent ichnofacies-dominated-porosity of the Biscayne aquifer from University of Texas-Austin CT- Imaging Laboratory. Images are used in lattice Boltzmann modeling and in production of solid-epoxy 3-dimensional models of macroporous limestone representative of the Biscayne aquifer to be used in magnetic resonance imaging (MRI) experiments. (d) Acquired 65 nautical miles of high-resolution marine seismic data within Biscayne National Park. (e) Mendenhall Postdoctoral Fellow began acquiring aquatic geochemical data every 2 weeks and instrumented a cave within a karstified hammock in Everglades National Park. (4) Task 4: (a) Barclay Shoemaker preformed final programming and the benchmark testing of his Conduit Flow Process (CFP) was completed. The CFP creates new ability for MODFLOW-2005 to simulate dual-porosity aquifer, such as the karst Biscayne aquifer. (b) Continued experiments at Florida International University-Department of Geological Sciences that are implementing use of lattice Boltzmann modeling to calculate macroporosity and hydraulic conductivity of a representative very-highly permeable ichnofacies-dominated-porous zone of the Biscayne aquifer. This group that includes a professor, a poctdoctoral student, and a Master's student calculated macroporosity and intrinsic permeability on computer renderings of 7 macroporous limestone samples representative of ground-water flow zones within the Biscayne aquifer using lattice Boltzmann computer modeling methods. They also demonstrated that they can create 3-dimensional computized volume renderings form digital optical borehole wall images and compute macroporosity and intrinsic permeability from these data. (c) Mendenhall Postdoctoral Fellow expedited the production of a 3-dimensionnal solid-epoxy model of a macroporous limestone outcrop sample of the Biscayne aquifer for use in magnetic resonance imaging (MRI) experiments at the New Mexico Resonance Laboratory during FY08.

Recent & Planned Products: Recent relevant publications that are linked to the study area and project goals: (1) Cunningham, K.J., Sukop, M.C., Curran, H.A., Wacker, M.A., and Dixon, J.F., 2008, Biogenic macroporosity within a high-frequency cyclostratigraphy and its impact on hydraulic conductivity and groundwater flow in the Biscayne aquifer, southeastern Florida, USA: A new view of karst: in prep.; (2) Shoemaker, W.B., Cunningham, K.J., Kuniansky, E.L., and Dixon, J.F., 2007, Impacts of turbulence on hydraulic heads and parameter sensitivities in preferential groundwater flow layers: Water Resources Research, in review. (3) Shoemaker W.B., Kuniansky E.L., Birk S., Bauer S and E.D Swain, 2007, Documentation of a Conduit Flow Process for MODFLOW-2005: USGS TM book 6, chap. A24; (4) Alvarez, P.F., 2007, Lattice Boltzmann modeling of fluid flow to determine the permeability of a karst specimen: M.S. Thesis, Florida International University, Miami, 96 p. (5) Cunningham, K.J., and Curran, H.A., 2007, Ichnogenic porosity, high-frequency cyclostratigraphy, and groundwater flow in the karst Biscayne aquifer, SE Florida, USA: Gingras, M.K., and Zonneveld, J.P.,. eds., International Ichnofabrics Workshop IX, Calgary, Alberta, Canada, August 11-16, Abstracts with Program, p. 12-15; (6) Sukop, M., Langevin, C. and Cunningham, K.J., 2006, Modeling Flow and Solute Transport in Karst Aquifers with Lattice Boltzmann Methods, Eos Transactions American Geophysical Union 87(52), Fall Meeting, Abstract H42C-08; (7) Florea, L.J., and Cunningham, K.J., 2007, Hydrostratigraphy of the Karst Aquifers of Florida: Karst Research Institute-Time in Karst, Short Scientific Paper, Postojna, Slovenia, March 14-18, 3 p; (8) Florea, L.J., and Cunningham, K.J., 2007, Geochemistry of groundwater within a karstified limestone hammock of Everglades National Park: Geological Society of America Annual Meeting, Oct. 28-31, Denver, CO, GSA Abstracts with Programs, v. 39, no. 6, in press; (9) Sukop, M., Huang, H., Alvarez, P.H., Cunningham, K.J., and C.D. Langevin, 2007, Applying Lattice Boltzmann, fractal, and geostatistical methods to karst: International Workshop on Scale Dependences in Soil and Hydrologic Systems, El Barco de Avila, Spain, July 3-6, PEDOFRACT 2007 Abstracts with Program, p. 18; (10) Sukop, M.C., Alvarez, P.F., Cunningham, K.J., and Langevin, C.D., 2007, Investigating non-Darcy flow in highly porous aquifer materials with lattice Boltzmann methods: Fourth International Conference for Mesoscopic Methods in Engineering and Science, Munich, Germany, July 16-20, Munich, Germany, p. 1; (11) Florea, L.J., and Cunningham, K.J., 2007, Geochemistry within a karstified limestone hammock of Everglades National Park: International Conference on Karst Hydrogeology and Ecosystems, August 13-15, Bowling Green, KY, http://hoffman.wku.edu/karst2007/abstract.html.; (12) Cunningham, K.J., Renken, R.A., Wacker, M.A., Zygnerski, M.R., Robinson, E., Shapiro, A.M., and Wingard, G.L., 2006, Application of carbonate cyclostratigraphy and borehole geophysics to delineate porosity and preferential flow in the karst limestone of the Biscayne aquifer, SE Florida, in Harmon, R.S., and Wicks, C., eds., Perspectives on karst geomorphology, hydrology, and geochemistry-A tribute volume to Derek C. Ford and William B. White: Geological Society of America Special Paper 404, p. 191-208.; (13) Cunningham, K.J., Wacker, M.A., Robinson, Edward, Dixon, J.F., and Wingard, G.L., 2006, A cyclostratigraphic and borehole geophysical approach to development of a three-dimensional conceptual hydrogeologic model of the karstic Biscayne aquifer, southeastern Florida: U.S. Geological Survey Scientific Investigations Report 2005-5235, 69 p; (14) Renken, R.A., Shapiro, A.M., Cunningham, K.J., Harvey, R.W., Metge, D.W., Zygnerski, M.R., Osborn, C.L., Wacker, M.A., and Ryan, J.N., 2005, Assessing the vulnerability of a municipal well field to contamination in a karst aquifer: Environmental and Engineering Geoscience, v. 11, no. 4, p. 341-354.; (15) Cunningham, K.J., Carlson, J.L., Wingard, G.L., and others, 2004, Characterization of aquifer heterogeneity using cyclostratigraphy and geophysical methods in the upper part of the Biscayne aquifer, southeastern Florida: relation to rock fabric and sequence stratgraphy. U.S. Geological Survey Water-Resources Investigations Report 03-4208, 46 p; (16) Cunningham, K.J., Wacker, M.A., Robinson, Edward, and others, 2004, Hydrogeology and ground-water flow at Levee-31N, Miami-Dade County, Florida, July 2003 to May 2004. U.S. Geological Survey Scientific Investigations Map I-2846, 1 sheet; (17) Cunningham, K.J., Carlson, J.I., and Hurley, N.F., 2004, New method for quantification of vuggy porosity from digital optical borehole images as applied to the karstic Pleistocene limestone of the Biscayne aquifer, southeastern Florida. Journal of Applied Geophysics: v. 55, p. 77-90; and (18) Cunningham, K.J., 2004, Application of ground-penetrating radar, digital optical borehole images, and cores for characterization of porosity hydraulic conductivity and paleokarst in the Biscayne aquifer, southeastern Florida, USA. Journal of Applied Geophysics: v. 55, p. 61-76.

Relevance to Greater Everglades Restoration Information Needs [See Plan on SOFIA's Web site: http://sofia.usgs.gov/publications/reports/doi-science-plan/]: This study supports several projects listed in the DOI science plan (specifically: Biscayne Bay Coastal Wetlands Project, L31N/L30 Seepage Management Pilot Project, Everglades National Park Seepage Management Project, Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement project, Lake Belt In-Ground Reservoir Technology Pilot Project, and Landscape-Scale Science Needed to Support Multiple CERP Projects) by including development of procedures for numerical simulations of ground-water flow in the karst Biscayne aquifer from the Northeast Shark Slough area, where the CERP L31N/L30 Seepage Management Pilot Project and Everglades National Park Seepage Management Projects will alter current hydropatterns in ENP, and seepage to the east. The development of an expanded conceptual karst hydrogeologic framework planned in this proposal will be used to assist development of procedures for numeric simulations to improve the monitoring and assessment of the response of the ground-water system to hydrologic changes caused by seepage-management pilot project implementation. Specifically, the development of procedures for ground-water modeling of the karst Biscayne aquifer in the area of Northern Shark Slough will help determine the appropriate hydrologic response to rainfall and translate that information into appropriate performance targets for input into the design and operating rules to manage water levels and flow volumes for the two Seepage Management Areas. Mapping of the karstic stratiform ground-water flow passageways in the Biscayne aquifer is recent and limited to a small area of Miami-Dade County adjacent to the Everglades wetlands (Cunningham and others, 2006a,b). Extension of this karst framework between the Everglades wetlands and coastal Biscayne Bay will aid in the simulation of coupled ground-water and surface-water flows to Biscayne Bay. The development of procedures for modeling in the karst Biscayne aquifer will useful to the establishment of minimum flows and levels to the bay and seasonal flow patterns. Also, these improved procedures for simulations will assist in ecologic modeling efforts of Biscayne Bay coastal estuaries.

This study supports the new USGS Science Strategy (USGS Circular 1309; 2007) by helping to develop a Water Census of the south Florida by providing new methods to link hydrogeology and aquifer characterization to ground-water modeling to be used for (1) a more precise determination of water use for meeting future human, environmental, and wildlife needs, and (2) establishing how freshwater is related to natural storage and movement of water, as well as engineered systems, water use, and related transfers. Further, this study supports the USGS Science Strategy by Leveraging Evolving Technologies in the areas of (1) paleobiology and its relation to fresh ground-water flow, (2) borehole geophysics (eg., digital optical borehole imaging), (3) surface geophysics (high-resolution marine seismic in Biscayne National Park), (4) 3-dimensional visualizations products of aquifer characteristics, (5) new hydraulic modeling technologies such as lattice Boltzmann methods, (6) computerized tomographic (CT) computer renderings of aquifer materials, (7) magnetic resonance imaging (MRI) of fluid flow in 3-dimensional models of aquifer materials, (8) building strong partnerships with University students and professors at Florida International University and Smith College, which are critical to advancing USGS science capabilities, and (9) building partnerships within the USGS through use of USGS Mendenhall Postdoctoral Program for conducting novel research.

This study provides support to a related GEPES-CESI study in progress by Melinda Lohmann titled “Coupled Surface Water and Ground Water Model to Simulate Past, Present and Future Hydrologic Conditions in DOI Managed Lands” by providing a new hydrogeologic framework between Everglades National Park and Biscayne National Park for future modeling efforts by Lohmann.

Key Findings:

1. Analysis of corehole data from the Lake Belt area suggests that much of the ground-water flow in this area is related to biogenic touching-vug porosity that forms tabular-shaped stratiform flow zones. Biogenic porosity and its hydrologic importance were determined by examining outcrops, cores, and borehole geophysical data that include digital optical image logs and flowmeter, fluid conductivity, and fluid temperature measurements.
2. Digital image logs and 72 of 85 geophysical measurements (85%) in 21 boreholes indicate that biogenic porosity is the principal pore type in ground-water flow zones. All the remaining borehole geophysical measurements across ground-water flow zones detected inflow or outflow from bedding plane vugs, with the exception of a single cavern-sized vug.
3. Biogenic porosity in the Biscayne aquifer is related to predictable vertical positions in stratigraphic cycles and much of it can be mapped reliably.
4. Computer-aided tomographic (CT) 3-D volume renderings of 7 macroporous limestone samples representative of highly-permeable Biscayne aquifer ground-water flow zones were used in lattice Boltzmann simulations to calculate macroporosity and intrinsic permeability values. Calculated intrinsic permeability values range between 0.35 and 152.96 m/s for six samples and 0.0 m/s for a seventh sample. Macroporoity values range between 15 and 81%.
5. The values of macroporosity and intrinsic permeability calculated from lattice Boltzmann methods are consistent with physical observations, borehole geophysical measurements, and tracer tests that indicate stratiform fossil moldic and ichnological related zones of highly permeable touching-vug porosity are very effective passageways for the flow of groundwater and advective transport of solutes.
6. FIU researchers involved in this study showed that they can create 3-dimensional computized volume renderings form digital optical borehole wall images and compute macroporosity and intrinsic permeability from these data with methods related to and involving lattice Boltzmann modeling. This methodology should go a long way to linking porosities and hydraulic conductivities at project coreholes to procedures used in traditional simulations of groundwater flow in the Biscayne aquifer between ENP and BNP.
7. The Conduit Flow Process (CFP) developed by Barclay Shoemaker for MODFLOW-2005 creates a new ability for MODFLOW-2005 to simulate dual-porosity aquifers in three modes by (1) coupling the traditional ground-water flow equation with formulations for a discrete network of cylindrical pipes (Mode 1), (2) inserting a high-conductivity flow layer that can transition between laminar and turbulent flow (Mode 2), or (3) simultaneously couple a discrete pipe nework while inserting a high-conductivity flow layer that can transition between laminar and turbulent flow (Mode 3). The groundwater flow simulations using CPF show that turbulent flow can be widespread within the Lake Belt Area between ENP and BNP in preferential flow layers of the Biscayne aquifer when horizontal hydraulic conductivities are above approximately 30,000 meters per day and critical Reynolds numbers are less than or equal to about 5.0.
8. Acquisition of high-resolution marine seismic data in Biscayne National Park is of good to excellent quality and should yield high-quality interpretive maps and cross-sections of the hydrostratigraphy beneath Biscayne National Park during the interpretive phase of this seismic task in FY08.