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Final Report: Regional Hydrologic Modeling With Emphasis on Watershed-Scale Environmental Stresses
EPA Grant Number: R825433C050Subproject: this is subproject number 050 , established and managed by the Center Director under grant R825433
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: EERC - Center for Ecological Health Research (Cal Davis)
Center Director: Rolston, Dennis E.
Title: Regional Hydrologic Modeling With Emphasis on Watershed-Scale Environmental Stresses
Investigators: Kavvas, M. Levant , Soong, Su-Tzai
Institution: University of California - Davis
EPA Project Officer: Levinson, Barbara
Project Period: October 1, 1996 through September 30, 2000
RFA: Exploratory Environmental Research Centers (1992)
Research Category: Center for Ecological Health Research , Targeted Research
Description:
Objective:The objective of this research project was to provide watershed-scale (1-km resolution) information on erosion/sediment loads, air-soil temperatures, surface water-soil moisture storages, wind, relative humidity, precipitation, and net solar radiation fields, with evapotranspiration and infiltration rates corresponding to critical climate scenarios of global climate change and droughts that can be applied to any ecosystem in California.
Summary/Accomplishments (Outputs/Outcomes):A 10-km resolution regional atmospheric/hydrologic model of Northern California was run for the 1989 drought conditions with good results. However, the atmospheric/hydrologic environmental stress information needed for ecosystem studies should have a resolution of 1 km or less. Also, from our conversations with the Clear Lake and Lake Tahoe ecosystem groups, it was clear that one of the primary environmental stresses on these systems is the erosion/sediment deliveries to the lakes. Because these processes are strongly driven by climate change, and because they operate on spatial scales of 1 km or less, it was necessary to refine the atmospheric/hydrologic model to this scale and use it to elucidate cause-and-effect relationships between critical climatic phenomena of droughts and floods and erosion/sediment deliveries to Lake Tahoe. Accordingly, a 4-km mesoscale atmospheric model was implemented for Northern California. Our physically based land surface parameterization was coupled with this mesoscale atmospheric model to obtain an integrated regional hydrologic/atmospheric model of California at 4-km resolution. The validation studies for this model with historical data were performed. Also, initial studies toward the development of a physically based watershed model were taken. This model will be used for the prediction of erosion/sediment and nutrient loads to Lake Tahoe.
Once validated at 4-km resolution over Northern California, the model can be focused further at 1-km resolution over the Lake Tahoe region to quantify the impact of critical climatic phenomena of droughts and floods on sediment delivery loads to the lake. The 1-km resolution regional atmospheric/hydrologic model of Lake Tahoe then can be applied to some selected watersheds in Lake Tahoe, using the recent California drought and flood periods for model verification. The Lake Tahoe ecosystem group has informed the investigators that they have collected voluminous runoff/sediment load data over several watersheds in Lake Tahoe in the past (see R825433C028). The coupled model can be validated by means of these historical data. Once the coupled model is validated, it can be run first over selected watersheds in Lake Tahoe to provide spatially distributed, 1-km resolution information on erosion/sediment deliveries and other atmospheric/hydrologic stresses resulting from droughts and floods.
The following activities were accomplished:
• We developed a watershed model for the estimation of sediment and phosphorus loading to Lake Tahoe. This comprehensive watershed model simulates the hydrology and the fate of pollutants such as sediment and nutrient to accurately estimate the influx of sediment and phosphorus into Lake Tahoe for further analysis of lake water clarity. With this model, alternative management scenarios can be evaluated to find the best management practice that can minimize the disturbance within the watersheds to improve the water quality of Lake Tahoe. The model is thought to have significant potential to serve as a useful decisionmaking tool for taking managerial actions. It allows watershed managers to assess the cost/benefits of various policy scenarios.
• Two applications of the Watershed Environmental Hydrology (WEHY) model to the Ward Creek Watershed in the Lake Tahoe Basin have shown that WEHY can reproduce the pattern of historical flow, sediment, and phosphorus loads with reasonable accuracy. Furthermore, the model performed consistently well for an independent data set. Overall comparisons were encouraging, and showed promise for the potential use of the WEHY model in studying the effects of different land management practices on ecological systems at both gauged and ungauged watersheds.
• The WEHY model is very effective at identifying the important hydrologic mechanisms of a basin of interest. Individual contributions from each hydrologic component of the model can be identified realistically by activating only that corresponding component. This would be difficult for traditional conceptual models to accomplish, as their hydrologic components do not physically model the hydrologic processes in question. Our model allows investigators to identify individual hydrologic mechanisms involved in larger processes.
• The WEHY model provides a framework for testing the efficiency of soil conservation and erosion control techniques at local and regional levels, and provides approaches and tools for environmentally based watershed management. Overall, our project enables agencies to set management priorities for reducing sediment and associated pollutants in watersheds.
Supplemental Keywords:ecosystem, ecosystem protection, environmental exposure and risk, geographic area, international cooperation, water, terrestrial ecosystems, aquatic ecosystem, aquatic ecosystem restoration, aquatic ecosystems and estuarine research, biochemistry, ecological effects, ecological indicators, ecological monitoring, ecology and ecosystems, environmental chemistry, restoration, state, water and watershed, watershed, watershed development, watershed land use, watershed management, watershed modeling, watershed restoration, watershed sustainability, agricultural watershed, exploratory research environmental biology, California, CA, Clear Lake, Lake Tahoe, anthropogenic effects, aquatic habitat, biogeochemical cycling, ecological assessment, ecology assessment models, ecosystem monitoring, ecosystem response, ecosystem stress, environmental stress, environmental stress indicators, fish habitat, hydrologic modeling, hydrology, integrated watershed model, lake ecosystems, lakes, land use, nutrient dynamics, nutrient flux, water management options, water quality, wetlands. , Ecosystem Protection/Environmental Exposure & Risk, Geographic Area, Scientific Discipline, Waste, RFA, Ecology, Aquatic Ecosystems & Estuarine Research, Ecological Risk Assessment, Aquatic Ecosystem, Fate & Transport, Hydrology, West Coast, Regional/Scaling, Monitoring/Modeling, Ecology and Ecosystems, State, California (CA), Sacremento River, Sacramento River Delta, Clear Lake, regional hydrologic modeling, hydrologic modeling, ecosystem health, Clear Lake , San Francisco Bay, Central Valley, Sierra Nevada Mountains, analytical models, environmental monitoring, Lake Tahoe, Sacramento River, hydrologic processes, aquatic ecosystems, atmospheric processes, environmental stress, modeling, Sierra Nevada, ecological models, transport
Relevant Websites:
Progress and Final Reports:
2000 Progress Report
Original Abstract
Main Center Abstract and Reports:
R825433 EERC - Center for Ecological Health Research (Cal Davis)
Subprojects under this Center:
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R825433C001 Potential for Long-Term Degradation of Wetland Water Quality Due to Natural Discharge of Polluted Groundwater
R825433C002 Sacramento River Watershed
R825433C003 Endocrine Disruption in Fish and Birds
R825433C004 Biomarkers of Exposure and Deleterious Effect: A Laboratory and Field Investigation
R825433C005 Fish Developmental Toxicity/Recruitment
R825433C006 Resolving Multiple Stressors by Biochemical Indicator Patterns and their Linkages to Adverse Effects on Benthic Invertebrate Patterns
R825433C007 Environmental Chemistry of Bioavailability in Sediments and Water Column
R825433C008 Reproduction of Birds and mammals in a terrestrial-aquatic interface
R825433C009 Modeling Ecosystems Under Combined Stress
R825433C010 Mercury Uptake by Fish
R825433C011 Clear Lake Watershed
R825433C012 The Role of Fishes as Transporters of Mercury
R825433C013 Wetlands Restoration
R825433C014 Wildlife Bioaccumulation and Effects
R825433C015 Microbiology of Mercury Methylation in Sediments
R825433C016 Hg and Fe Biogeochemistry
R825433C017 Water Motions and Material Transport
R825433C018 Economic Impacts of Multiple Stresses
R825433C019 The History of Anthropogenic Effects
R825433C020 Wetland Restoration
R825433C021 Sierra Nevada Watershed Project
R825433C022 Regional Transport of Air Pollutants and Exposure of Sierra Nevada Forests to Ozone
R825433C023 Biomarkers of Ozone Damage to Sierra Nevada Vegetation
R825433C024 Effects of Air Pollution on Water Quality: Emission of MTBE and Other Pollutants From Motorized Watercraft
R825433C025 Regional Movement of Toxics
R825433C026 Effect of Photochemical Reactions in Fog Drops and Aerosol Particles on the Fate of Atmospheric Chemicals in the Central Valley
R825433C027 Source Load Modeling for Sediment in Mountainous Watersheds
R825433C028 Stress of Increased Sediment Loading on Lake and Stream Function
R825433C029 Watershed Response to Natural and Anthropogenic Stress: Lake Tahoe Nutrient Budget
R825433C030 Mercury Distribution and Cycling in Sierra Nevada Waterbodies
R825433C031 Pre-contact Forest Structure
R825433C032 Identification and distribution of pest complexes in relation to late seral/old growth forest structure in the Lake Tahoe watershed
R825433C033 Subalpine Marsh Plant Communities as Early Indicators of Ecosystem Stress
R825433C034 Regional Hydrogeology and Contaminant Transport in a Sierra Nevada Ecosystem
R825433C035 Border Rivers Watershed
R825433C036 Toxicity Studies
R825433C037 Watershed Assessment
R825433C038 Microbiological Processes in Sediments
R825433C039 Analytical and Biomarkers Core
R825433C040 Organic Analysis
R825433C041 Inorganic Analysis
R825433C042 Immunoassay and Serum Markers
R825433C043 Sensitive Biomarkers to Detect Biochemical Changes Indicating Multiple Stresses Including Chemically Induced Stresses
R825433C044 Molecular, Cellular and Animal Biomarkers of Exposure and Effect
R825433C045 Microbial Community Assays
R825433C046 Cumulative and Integrative Biochemical Indicators
R825433C047 Mercury and Iron Biogeochemistry
R825433C048 Transport and Fate Core
R825433C049 Role of Hydrogeologic Processes in Alpine Ecosystem Health
R825433C050 Regional Hydrologic Modeling With Emphasis on Watershed-Scale Environmental Stresses
R825433C051 Development of Pollutant Fate and Transport Models for Use in Terrestrial Ecosystem Exposure Assessment
R825433C052 Pesticide Transport in Subsurface and Surface Water Systems
R825433C053 Currents in Clear Lake
R825433C054 Data Integration and Decision Support Core
R825433C055 Spatial Patterns and Biodiversity
R825433C056 Modeling Transport in Aquatic Systems
R825433C057 Spatial and Temporal Trends in Water Quality
R825433C058 Time Series Analysis and Modeling Ecological Risk
R825433C059 WWW/Outreach
R825433C060 Economic Effects of Multiple Stresses
R825433C061 Effects of Nutrients on Algal Growth
R825433C062 Nutrient Loading
R825433C063 Subalpine Wetlands as Early Indicators of Ecosystem Stress
R825433C064 Chlorinated Hydrocarbons
R825433C065 Sierra Ozone Studies
R825433C066 Assessment of Multiple Stresses on Soil Microbial Communities
R825433C067 Terrestrial - Agriculture
R825433C069 Molecular Epidemiology Core
R825433C070 Serum Markers of Environmental Stress
R825433C071 Development of Sensitive Biomarkers Based on Chemically Induced Changes in Expressions of Oncogenes
R825433C072 Molecular Monitoring of Microbial Populations
R825433C073 Aquatic - Rivers and Estuaries
R825433C074 Border Rivers - Toxicity Studies