Automated Geospatial Watershed Assessment (agwa): a Gis-based Hydrologic Modeling Tool for Watershed Management and Landscape Assessment

The Automated Geospatial Watershed Assessment (AGWA, see: www.tucson.ars.ag.gov/agwa) tool is a GIS interface jointly developed by the USDA-Agricultural Research Service, the U.S. Environmental Protection Agency, the University of Arizona, and the University of Wyoming to automate the parameterization and execution of the Soil Water Assessment Tool (SWAT) and KINEmatic Runoff and EROSion (KINEROS2) hydrologic models. By employing these two models AGWA can conduct hydrologic modeling and watershed assessments at multiple time and space scales. AGWA uses commonly available, national, GIS data layers to fully parameterize, execute, and visualize results from both the SWAT and KINEROS2. Through an intuitive interface the user selects an outlet from which AGWA delineates and discretizes the watershed using a Digital Elevation Model (DEM). The watershed model elements are then intersected with soils and land cover data layers to derive the requisite model input parameters. The chosen model is then run, and the results are imported back into AGWA for visual display. This allows managers to identify potential problem areas where additional monitoring can be undertaken or mitigation activities can be focused. AGWA can difference results from multiple simulations to examine relative change over a variety of input scenarios (e.g. climate/storm change, land cover change, present conditions and alternative futures). The AGWA tool is being further developed for online decision support to provide ready access to environmental decisionmakers, resource managers, researchers, and user groups. In addition, a variety of new capabilities have been incorporated into AGWA. They include handling FAO soils for international application; preand post-fire watershed assessments; and, multiple options for user defined land cover change. An overview of AGWA and these capabilities will be presented.