GIS-BASED HYDROLOGIC MODELING: THE AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT TOOL

1. GIS-BASED HYDROLOGIC MODELING:THE AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT TOOL Bill Kepner and Darius Semmens US – EPA Landscape Ecology Branch Las Vegas, NV David Goodrich, Mariano Hernandez, Shea Burns, Averill Cate, Soren Scott, Lainie Levick, Evan Canfield USDA-ARS Southwest Watershed Research Center, Tucson, AZ Phillip Guertin University of Arizona, Tucson, AZ Scott Miller University of Wyoming, Laramie, WY

2. Introduction • PC-based GIS tool for watershed modeling • KINEROS & SWAT (modular) • Investigate the impacts of land-use/cover change on runoff, erosion, and water quality at multiple scales • Compare and visualize results • Targeted for use by research scientists and management specialists • Analyses can be integrated with those from other GIS- based tools & data • Widely applicable & free

3. Objectives of the AGWA tool • Compatible with US-EPA Analytical Tool Interface for Landscape Assessment (ATtILA) • Simple, direct method for model parameterization • Provide accurate, repeatable results • Utilize basic, commonly available GIS data • Assess impacts of land-use/cover change • Useful for scenario development, alternative futures simulation work (forecasted change)

4. KINEROS Outputs SWAT Outputs Channel Infiltration (m3/km) Precipitation (mm) Plane Infiltration (mm) ET (mm) Runoff (mm or m3) Percolation (mm) Sediment yield (kg) Channel Disch. (m3/day) Peak flow (m3/s or mm/hr) Transmission loss (mm) Channel Scour (mm) Water yield (mm) Sediment discharge (kg/s) Sediment yield (t/ha) AGWA Conceptual Design: Inputs and Outputs Watershed Delineation using Digital Elevation Model (DEM) Watershed Discretization (model elements) Intersect model elements with + Soils Land Cover Output results that can be displayed in AGWA Rain (Observed or Design Storm) Run model and import results Results

5. High urban growth 1973-1997 Sierra Vista Subwatershed KINEROS Results Concentrated urbanization ARIZONA Phoenix # Tucson # SONORA Forest Oak Woodland Mesquite Desertscrub Grassland Urban 1997 Land Cover • Using SWAT and KINEROS for integrated watershed assessment • Land-cover change analysis and impact on hydrologic response Spatial and Temporal Scaling of Results Upper San Pedro River Basin N Water yield change between 1973 and 1997 <<WY >>WY SWAT Results

6. Land-Cover Modification Tool • Allows users to build and test management scenarios • Location of land-cover alterations specified by either drawing a polygon on the display, or specifying a polygon map • Types of Land-Cover Changes: • Change entire user-defined area to new land cover • Change one land-cover type to another in user-defined area • Change land-cover type within user-supplied polygon map • Create a random land-cover pattern • e.g. simulated burn pattern • Example of land-cover change (mesquite removal) and associated hydrologic impacts

7. AGWA Applications • Engineering design – optimizing placement and sizing of retention basins for storm-water recharge to capture excess flows resulting from urbanization • Planning – hydrologic impacts of alternative growth scenarios • TMDLs – locating potential impairment (cheap & quick)

8. Integration of AGWA and ATtILA • Exploits landscape characterization functionality of ATtILA to improve parameterization of SWAT in AGWA • Incorporates outputs (e.g. sediment yield) from AGWA back into landscape metric assessments • Examples from Arizona (Hernandez et al., 2003) and Oregon (in progress) Hernandez et al., 2003, Integrating a landscape/hydrologic analysis for watershed assessment. Proceedings of the First Interagency Conference on Research in the Watersheds, Benson, AZ October 27-30, 2003.

9. AGWA Milestones • AGWA 1.1 released at the Fed. Interagency Hydrologic Modeling Conference, July 2002. • AGWA was added to the new ORD Council for Regulatory Environmental Modeling (CREM) database in January, 2004 • AGWA 1.4 released in July, 2004 • AGWA was exhibited as a TMDL tool at the 2004 EPA Science Forum Product Expo • AGWA was integrated into the BASINS 3.1 release • in August, 2004 • Training: Las Vegas (2001); Reston (2002); Tucson (2003); San Diego (2004); India (2005); Bulgaria (2005) • 850 registered users – April 2005

10. Key Improvements for National Application AGWA/BASINS Integration • Elevation bands for SWAT • SSURGO soil parameterization for SWAT • Enhanced ground-water parameterization for SWAT • Multiple hydraulic-geometry relations for channel characterization • Land-Cover Modification Tool – scenario development • Reservoirs (SWAT), and ponds (KINEROS) • FAO Soils – transborder applications

11.         Applications • National • NYCDEP – Catskill/Delaware • USDA-ARS & Upper San Pedro Partnership – Arizona • EMAP – Oregon (AGWA-ATtILA) • ReVA – SEQL • Region 10 – Kenai Peninsula, Alaska • International • NATO – Committee on the Challenges to Modern Society (CCMS) • Southwest Consortium for Environmental Research and Policy (SCERP) – U.S./Mexico • UNESCO – Global Network for Water and Development Information (G-WADI)

12. AGWA Support & Distribution • Research Plan • Code structure diagrams • Training exercises (4) • Data (FAO soil, NWS gauge, & training exercise data) • Journal Publications (e.g. Hernandez et al. 2000, Miller et al. 2002a, Miller et al. 2002b, Kepner et al. 2004, Semmens & Goodrich 2005; Goodrich et al. 2005) • Community Bulletin Board • All available on EPA and USDA/ARS companion Websites: • Fact Sheets, Product Announcement, Brochures • Documentation and User Manuals for AGWA and BASINS-AGWA (html & pdf) • Quality Assurance Report http://www.epa.gov/nerlesd1/land-sci/agwa/ http://www.tucson.ars.ag.gov/agwa/

13. Future Directions Migrating to ArcGIS (AGWA 2.0) and the Internet (DotAGWA) • Detailed, peer reviewed design plan completed March, 2005 • Compatible with plans for BASINS and ATtILA • Developed using standards-based technology allowing AGWA components to be utilized by other applications and visa versa • Facilitates integration of other models/tools