About AGWA

Planning and assessment in land and water resource management are evolving from simple, local-scale problems toward complex, spatially explicit regional ones. Such problems have to be addressed with distributed models that can compute runoff and erosion at different spatial and temporal scales. The extensive data requirements and the difficult task of building input parameter files, however, have long represented an obstacle to the timely and cost-effective use of such complex models by resource managers. Using GIS data in combination with automated functionality offers a method to greatly reduce the time and effort required to prepare such input files for various models, and allows users to delineate watersheds, discretize them into modeling elements, and then parameterize these elements for these models in a rapid manner.

To facilitate this process, AGWA was created through a joint effort begun by the USDA-ARS Southwest Watershed Research Center and the U.S. EPA Office of Research and Development Landscape Ecology Branch and expanded to include the University of Arizona and the University of Wyoming. It has been under continual development to incorporate new features and functionality and has seen multiple major and minor releases, including but not limited to: AGWA 1.3 for ArcView 3.x in 2002 (initial AGWA release); AGWA 2.0 for ArcGIS 9.x in 2007 (initial ArcGIS/ArcMap 9.x release); AGWA 2.4 for ArcGIS 10.x in 2011 (initial ArcGIS/ArcMap 10.x release); and AGWA 3.x for ArcGIS 10.x in 2013 (current major release for ArcGIS/ArcMap 10.x).

KINEROS2 (KINematic runoff and EROSion) is an event oriented, physically-based model developed at the USDA-ARS to describe the processes of interception, infiltration, surface runoff, and erosion from small- to medium-sized watersheds. The watershed is represented by a cascade of planes and channels, thereby allowing rainfall, infiltration, runoff, and erosion parameters to vary spatially. KINEROS2 may be used to determine the effects of various artificial features such as urban developments, small detention reservoirs, or lined channels on flood hydrographs and sediment yield. Though KINEROS2 has been applied over a wide range of scales, from plot (<10 m²) to large watersheds on the order of a thousand square kilometers, it has only been thoroughly validated for watersheds on the order of a hundred square kilometers where sufficient observations exist in experimental watersheds For more information on KINEROS2, please visit http://www.tucson.ars.ag.gov/kineros.

The Soil and Water Assessment Tool (SWAT) is a quasi-distributed model developed at the USDA-ARS to predict the impact of land use, land management practices, and climate change on water, sediment, and agricultural chemical yields in small- to river basin-scale complex watersheds with varying soils, land use, and management conditions over long periods of time (> 1 year). SWAT is a continuous-time model, i.e. a long-term yield model, using daily average input values, and is not designed to simulate detailed, single-event flood routing. For more information on SWAT, please visit http://swat.tamu.edu.