HYDROLOGICAL AND WATER QUALITY SYSTEM, PHASE II
Grassland, Soil and Water Research Laboratory
2009 Annual Report
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.
At the request of USEPA Office of Water, we will develop a water quality modeling system to estimate the potential effects of EPA environmental programs for the entire nation. A database design document was written to guide development of the modeling system. A SWAT (Soil and Water Assessment Tool) simulation was completed for the Upper Mississippi River Basin and validated for stream flow, sediment, nutrients, and corn and soybean yields. We are currently running scenarios to determine the impact of biofuel production on the environment. A conceptual model was developed to simulate the fate and transport of heavy metals, including mercury, zinc, copper, and iron, across the landscape and through river channels. Progress was made on a conceptual model for pharmaceutical transport including hormones and antibiotics. Datasets for model development and validation from Austin, TX, and the Colorado front range are being assembled.