U.S. Environmental
                Protection
                Agency
                            EPA/600/C-06/001
                               ARS/137460
 USDA    AGWA  -  Automated  Geospatial
                Watershed Assessment
What is AGWA?

The Automated Geospatial Watershed Assessment
(AGWA) tool is an interface designed to run two water-
shed runoff and erosion models: the Kinematic Runoff
and Erosion (KINEROS) model, and the Soil and Water
Assessment Tool (SWAT). The interface was developed
in a geographic information system (GIS) to facilitate
the preparation of model inputs, and the visualization
of model outputs.

AGWA is an extension for ArcView versions 3.X. It is
available as a stand-alone tool, or as an integrated part
of BASINS (Better Assessment Science Integrating point
and Nonpoint Sources) version 3.1.
How can AGWA help with TMDLs?

• Locating potential impairment
  -  AGWA can quickly and inexpensively identify and
    prioritize problem areas at the basin and watershed
  scales

• Evaluating the impacts of land-use change
  -  AGWA can evaluate where water-quality impacts
    of past and future landscape change are most
    significant
  -  AGWA includes a land-cover modification tool to
    assist with scenario development

• Mapping results
  -  All model outputs for both streams and upland
    areas can be mapped to facilitate comparisons with
    other data layers and the presentation of results

Where can I get AGWA?

AGWA example datasets, training exercises, and docu-
mentation can be downloaded via the Internet free of
charge from:
           www.tucson.ars.ag.gov/agTva
                     or
       www.epa.gov/nerlesdl/land-sci/agwa

BASINS-AGWA can be downloaded with BASINS ver-
sion 3.1 from:
    www.epa.gov/docs/ostwater/BASINS
       AGWA Inputs and Outputs
Digital Elevation
 Model (DEM)
Model Elements
 Results
   Output results that can be displayed in AGWA
KINEROS Outputs
Channel infiltration (m3/km)
Plane infiltration (mm)
Runoff (mm or m3)
Sediment yield (kg)
Peak flow (m3/s or mm/hr)
Channel scour (mm)
Sediment discharge (kg/s)
SWAT Outputs
Precipitation (mm)
ET(mm)
Percolation (mm)
Surface runoff (mm)
Transmission loss (mm)
Water yield (mm)
Sediment yield (t/ha)
217LEB04-FS-AGWA

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       AGWA -  Automated Geospatial Watershed
                                     Assessment
What's Next?

• Migration to ArcGIS - AGWA and BASINS exten-
sions are currently being developed for ArcGIS

• DotAGWA - a web-based interface for AGWA is
  currently under development.  The interface will
  allow users to access all of the same functionality of
  AGWA without purchasing expensive GIS software,
  or downloading and projecting data. DotAGWA will
  also allow users to develop land-use management
  scenarios, and simulate their impacts on water and
  sediment yields.
System Requirements
To use AGWA, you will need version 3.1 or later of
Arc View and version 1.1 of the Spatial Analyst exten-
sion. AGWA works with Windows 95, 98, 2000, NT,
ME, and XP operating systems.
For Further Information
For further information contact:

U.S. EPA/ORD/NERL
Landscape Ecology Branch
Darius Semmens (semmens.darius@epa.gov)
William Kepner (kepner.william@epa.gov)

USDA-ARS
Southwest Watershed Research Center
David Goodrich (dgoodrich@tucson.ars.ag.gov)
 ssp
     -1.617-1.33
     1.33-4.278
 /V 4.278 - 7.225
 A/7.225-10.173
 A/10.173-13.12
 A/13.12-16.068
 A/16.068-19.015
 A/19.015-21.963
 A*21.963-24.91
     No Data

     -2.729-3.13
     3.13-8.989
     8.989-14.847
     14.847-20.706
     | 20.706 - 26.565
     | 26.565 - 32.424
     | 32.424 - 38.282
     | 38.282-44.141
     | 44.141-50
     I No Data
                                                   5  0  5 10 15 20 25 Kilometers
Simulated change in
average annual
sediment yield (t/ha)
over a 20-year period
as a result of land-use
change for the Upper
San Pedro Basin (U.S./
Mexico).

                                                                                       May 2004

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