USING U.S. EPA BASINS MODELING SYSTEM FOR LINKING HYDROLOGIC MODELS WITH AN ECOLOGICAL MODEL FOR AQUATIC ENDPOINT IMPACT ASSESSMENTS

The U.S. Environmental Protection Agency's (EPA's) Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is a multipurpose environmental analysis system designed to perform watershed and water quality-based studies. It was developed to facilitate the examination of environmental information, to support analysis of environmental systems, and to provide a framework for examining management alternatives. BASINS integrates environmental data, analytical tools, and modeling programs under a Geographic Information System (GIS). The current release of BASINS, version 4.0, is the first to be based primarily on a non-proprietary, open-source GIS foundation. BASINS encompasses a growing suite of watershed and water quality models, from sophisticated broad-spectrum watershed models to agricultural and ecological models to planning and management level models.

Of the variety of models available in BASINS, two are presented to demonstrate the linkage between hydrologic and ecological models for conducting biological impact assessments: Hydrological Simulation Program-FORTRAN (HSPF), and AQUATOX. HSPF (Bicknell and others, 2005) watershed modeling code is a comprehensive, process-based mathematical model developed under joint U.S. EPA and U.S. Geologic Survey (USGS) sponsorship for simulating hydrologic and water quality processes in natural and man-made water systems. AQUATOX, a mechanistic and dynamic fate and effects model developed with funding from the U.S. EPA, simulates the significant physical, chemical, and biological processes affecting aquatic biota in streams, rivers, ponds, lakes, reservoirs, and estuaries (Park and others, 2008). AQUATOX represents and predicts compositional shifts for periphyton, phytoplankton, invertebrates, and fish with changes in N, P, and sediment loadings.

The methodology and results of a BASINS application on Fort Benning, GA is presented as a case study. The Fort Benning Study incorporates military-specific land use categories to identify impacts to aquatic biota such as the broadstripe shiner. Additionally, the discussion is expanded to include how this study and others can incorporate climate change risk evaluations by applying the newly developed Climate Assessment Tool (CAT) (U.S. EPA, 2009). CAT incorporates climate change scenarios by modifying a user-driven base period of historical temperature and precipitation data to reflect any desired future changes.

Bicknell, B.R., Imhoff, J.C., Kittle, J.L. Jr, 2005, Hydrological Simulation Program - FORTRAN (HSPF), User's manual for release 12.2, U.S. EPA National Exposure Research Laboratory, Athens, GA, in cooperation with U.S. Geological Survey, WRD, Reston, VA.

Park, R. A., Clough, J. S., and Wellman, M. C., 2008, AQUATOX: Modeling Environmental Fate and Ecological Effects in Aquatic Ecosystems, Ecological Modeling 213:1-15.

U.S. Environmental Protection Agency, 2009, BASINS 4.0 Climate Assessment Tool: Supporting Documentation and User's Manual (Final Report), U.S. EPA Washington, DC, EPA/600/R-08/088F.