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SOURCE WATER AREA DELINEATION OF PUBLIC WATER SUPPLY WELLS USING WHAEM2000. INTERNATIONAL GROUND WATER MODELING CENTER NEWSLETTER, V.19(1):4
Kraemer, S R. SOURCE WATER AREA DELINEATION OF PUBLIC WATER SUPPLY WELLS USING WHAEM2000. INTERNATIONAL GROUND WATER MODELING CENTER NEWSLETTER, V.19(1):4. U.S. Environmental Protection Agency, Washington, DC, 2001.
Develop, test, and refine models to evaluate sub-basins to determine whether local water quality problems due to excessive nutrient loading exist, and if so, to characterize them and determine their relationships to nutrient loading. Develop models to simulate overland flow and non-point source pollutant loads to track and assess nutrient loadings across watersheds and provide approaches for estimating nutrient budgets within sub-basins and for predicting changes in nutrient budgets in response to changes in watershed activities/land use/land cover. Demonstrate the application of the recommended approach/models for predicting changes in nutrient budgets in response to changes in proposed watershed activities/land use/land cover, resulting in specific recommendations for reducing the nutrient loads to a basin. For coherence, cooperation, and economics, these models will be housed in a unified, consistent, computational environment for environmental analyses that allows teaching (i.e., technology transfer) to multiple users (users concentrate on problem, not model input/output); that appeals to multi-disciplinary groups for distribution and use as a consistent assessment methodology (includes models, tools, modular design and facilitated updates of science/engineering); that includes resident visualization, animation tools, documentation and tutorials on-line, hooks to GIS and environmental databases; and is executable on UNIX, personal computers, and HPC resources.
Objective # 2.2 Conserve and enhance nation's waters: By 2005, conserve and enhance the ecological health of the nation's (state, interstate, and tribal) waters and aquatic ecosystems-rivers and streams, lakes, wetlands, estuaries, coastal areas, oceans, and groundwater-so that 75% of waters will support healthy aquatic communities.
WhAEM2000 is computer program that solves steady state ground-water flow and advective streamlines in homogeneous, single layer aquifers. The program was designed for capture zone delineation in support of protection of the source water area surrounding public water supply wells. The computational engine within the software is based on the analytic element method, with point sinks for representing wells, line-sinks for rivers, no-flow line elements for impermeable boundaries, uniform flow functions to lump far-field boundaries, and a rainfall function for representing constant recharge. The development of WhAEM2000 has been a cooperative effort between the US Environmental Protection Agency Office of Research and Development, the EPA Office of Ground Water and Drinking Water, Indiana University, and the University of Minnesota.
WhAEM2000 is intended to support conceptual model development and testing in a step-wise approach. The EPA Report "Working with WhAEM2000" guides the user through a wellhead protection case study involving the wellfield of the city of Vincennes, Indiana, which is located in glacial valley fill. WhAEM2000 supports capture zone delineation based on radius methods, well in uniform flow solutions, and geohydrologic modeling. Protection areas are designed and overlaid upon electronic base maps. The base maps are based on US Geological Survey Digital Line Graph (DLG) or DXF sources. The release of streamlines from the well radius, backward into the gradient, of length related to residence time, provides the basis of the capture zone. Observed heads can be placed on the basemap as test points, and the difference between simulated heads to observed heads can be represented graphically with triangles that are sized based on the magnitude of residual and colored based on the sign of residual. WhAEM2000 has on-line help and tutorials.
The WhAEM2000 graphical user interface was written in Visual Basic by Vic Kelson. The Fortran solution engine is based on the code ModAEM by Vic Kelson. Access to Henk Haitjema's GFLOW solution engine, including resistance line-sinks and inhomogeneity elements, is planned in a future release.
WhAEM2000 software, user guide, and binary basemaps can be downloaded from the EPA Center for Exposure Assessment Modeling (http://www.epa.gov/ceampubl/whaesmap.htm) or the EPA Center for Subsurface Modeling Support (http://www.epa.gov/ada/csmos/models/whaemwin.html).
Training courses in Source Water Delineation using WhAEM2000 will be offered through the EPA Drinking Water Academy (http://www.epa.gov/safewater/dwa.html).