Automated Geospatial Watershed Assessment Tool (AGWA)

The Automated Geospatial Watershed Assessment tool (AGWA, see: www.tucson.ars.ag.gov/agwa or http://www.epa.gov/esd/land-sci/agwa/) 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 a suite of hydrologic and erosion models (RHEM, KINEROS2 and SWAT). Through an intuitive interface the user selects an outlet from which AGWA delineates anddiscretizes the watershed using a Digital Elevation Model (DEM). The watershed modelelements are then intersected with terrain, soils, and land cover data layers to derive the requisitemodel input parameters. The chosen model is then run, and the results are imported backinto AGWA for graphical display. 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, implementation of BMPs, present conditions and alternative futures).This allows managers to identify potential problem areas where additional monitoring can be undertaken or mitigation activities can be focused. Application examples of AGWA will be presented including post-fire assessment, implementation of rangeland BMPs, green infrastructure, and future change analysis. Versions of AGWA are available for ESRI ArcView 3.x and ArcGIS 9.x and 10.x.