1a. Objectives (from AD-416):
The overall objective of this project is to develop a national water quality modeling system that would provide input data for applications of multiple water quality models for EPA's Office of Water. The system will consist of input data organized around the National Hydrography Dataset (NHD) stream reaches and catchments, and input file configuration subroutines to support applications of both USDA's Soil and Water Assessment Tool (SWAT) and USGS's Spatially Referenced Regressions on Watershed Attributes (SPARROW). Phase II will include finer spatial resolution down to 4 square kilometer grid cells which allows local assessment. Phase II will also include simulation of the fate and transport of selected heavy metals and pharmaceuticals.
1b. Approach (from AD-416):
The Hydrologic and Water Quality System will be an extension of the Hydrologic Unit Model of the United States (HUMUS), which has recently been upgraded for USDA's Conservation Effects Assessment Project (CEAP). The system developed in this project will extend CEAP-HUMUS by upgrading modeling capabilities and improving the quality of input data. Specifically, input data will be re-formatted or replaced with data organized around NHD stream segments and catchment delineations.
3. Progress Report:
The SWAT (Soil and Water Assessment Tool) model was parameterized for the Upper Mississippi, Ohio, and Tennessee river basins using the USGS (United States Geological Survey) 12-digit subwatersheds as subbasins (approximately 100 Km**2). Output from the USGS SPARROW ((SPAtially Referenced Regressions on Watershed) regression model is being assembled to validate total annual sediment, nitrogen and phosphorus loads at each 12-digit outlet. SWAT is currently being parameterized for all watersheds defined by the National Hydrology Dataset (3,000,000 subwatersheds in the conterminous United States). A web-based interface for extracting 8-digit SWAT model runs and for running SWAT on a remote server was developed. A conceptual model for fate and transport of pharmaceuticals (hormones and antibiotics) across the landscape was refined. Experts in fate and transport of pharmaceuticals from Louisiana State University, Texas A&M University, and Baylor University were consulted to refine the conceptual model. The model is currently being parameterized for different classes of hormones and pesticides.