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The San Pedro Geo-Data Browser was developed by the Landscape Ecology Branch of the U.S. Environmental Protection Agency (Las Vegas, NV) with the assistance and collaboration of the Southwest Watershed Research Center of the USDA Agricultural Research Service (Tucson, AZ). The goal of the Landscape Sciences Program is to improve decision-making relative to natural and human resource management through the development of an integrated system of landscape change detection metrics and models. The program has proceeded simultaneously along two lines, 1) a research component to develop and test landscape indicators and assessment protocols, and 2) an implementation component to demonstrate the application of landscape analysis protocols to ecological and hydrological assessments via a number of geographic initiatives.

Acquisition of primary data and database development are an initial feature of any landscape indicator and assessment project. Since 1995, U.S. Environmental Protection Agency (EPA) and USDA Agricultural Research Service (USDA/ARS) scientists have been working as part of the multi-agency Semi-Arid Land-Surface-Atmosphere (SALSA) research consortium dedicated to the study of global change and subsequent consequences within the Upper San Pedro Watershed.

The watershed study location originates in Sonora, Mexico and flows north into southeastern Arizona. The San Pedro River is an international basin with significantly different cross border legal and land use practices. The watershed embodies a variety of characteristics which make it an exceptional outdoor laboratory for addressing a large number of scientific questions in arid and semi-arid hydrology, ecology, meteorology, and the social and policy sciences. The Upper San Pedro Watershed represents a transition area between the Sonoran and Chihuahuan deserts and topography, climate, and vegetation vary substantially across the watershed. Elevation ranges from 900 - 2,900 m and annual rainfall ranges from 300 to 750 mm. Biome types include desertscrub, grasslands, oak woodland-savannah, mesquite woodland, riparian forest, coniferous forest, and agriculture. The upper watershed encompasses an area of approximately 7,600 km2 (5,800 km2 in Arizona and 1,800 km2 in Sonora, Mexico). Additional information on the San Pedro Watershed has been summarized into both English and Spanish version Fact Sheets for user convenience.

Users are referred to the following web sites to learn more about the EPA research within the Upper San Pedro Watershed and the multi-agency SALSA research consortium:
EPA, Upper San Pedro Watershed Web Site
Semi-Arid Land-Surface-Atmosphere (SALSA) Web Site
http://www.tucson.ars.ag.gov/salsa/salsahome.html Exit EPA Disclaimer

The role of the EPA research has been to develop change detection and accuracy assessment methodologies, landscape indicators, landscape hydrological models, landscape analysis and assessment tools, and watershed assessments. The continuing work in the San Pedro has resulted in the accumulation of spectral image files from a variety of satellite and aircraft-based sensor platforms and a number of spatial data coverages for land, natural resource, and socioeconomic factors. The information contained within the San Pedro River Geo-Data Browser has been acquired from multiple sources and includes data generated within the EPA and USDA-ARS. All coverages have been subset within the project area from its source near Cananea, Sonora to a pour-point associated with the U.S. Geological Survey gauging station located near Redington, Arizona. Additional information on the San Pedro Watershed Database has been summarized into both English and Spanish version Fact Sheets for user convenience.

The spatial coverages and the supporting information (metadata) have been organized into three data subsets relative to their geographical availability, i.e. the entire Upper San Pedro Watershed, and the Arizona and Sonora portions of the watershed, respectively. The coverages are available for download and the metadata include important information relative to acquisition, location, processing level, file size and format, and any relevant comments.

The intent of the San Pedro Geo-Data Browser is to provide spatial data in accessible on-line and CD formats to other researchers, public agencies, resource managers, non-governmental organizations, decision-makers, and user groups. A case study on using science to influence integrated decision-making for watershed management in the San Pedro is provided as a Fact Sheet for user convenience.  The Geo-Data Browser provides for long term record keeping (archiving) with easy access to an exceptional assemblage of spatial data for the Upper San Pedro River, a watershed of international significance. The original Data Browser was completed in February 2000 (EPA/600/C-00/002) and revised in 2003 to provide additional coverages with consistent metadata.

Additionally, two ArcView analysis extensions have been added to the Geo-Data Browser. These are custom tools developed by EPA and USDA/ARS that utilize the database spatial coverages as input data. The Analytical Tools Interface for Landscape Assessments (ATtILA) tool provides the ability to generate commonly used metrics to examine interactions between landscape pattern and distribution relative to ecological processes. The Automated Geospatial Watershed Assessment (AGWA) tool has been designed to investigate the hydrologic impacts of land-cover change over time and utilizes two watershed runoff and erosion models, i.e. KINEROS and SWAT. Both extension tools operate through intuitive interfaces requiring relatively little Geographic Information System, ecological or hydrologic expertise. Their purpose is to provide managers and scientists with easily applied tools for planning, management, and research applications. Additional information about the assessment tools can be found in Fact Sheets for AGWA and ATtILA.

Using the Geo-Data Browser

For best viewing of the San Pedro Geo-Data Browser web site, the Windows desktop viewing area should be set to 1024 by 768 pixels or higher.  Some 15-inch monitors may require adjustments to the desktop viewing area.  If adjustment is required, do the following:

  1. Open your Windows Control Panel
  2. Double click on the Display icon
  3. Select the Settings folder tab
  4. Adjust the Desktop/Screen Area to 1024 by 768 pixels or higher
  5. Select Apply/OK

For Microsoft Internet Explorer users, the Geo-Data Browser web site is best viewed with the text size set to 'medium'.  To change this setting, do the following:

  1. Open MS Internet Explorer
  2. From the View menu, select Text Size
  3. From the Text Size menu, select 'medium'


Users are advised that the majority of coverages within the database have been provided by a number of other agencies. Verification of the quality and use of any data supplied via this product are the responsibility of the user.  In addition, some of the data included within this database have been derived from uncalibrated hydrologic models (KINEROS and SWAT).  These data are provided only as an example of the outputs from AGWA; they do not represent observed values, and should not be used for scientific analysis.

EPA Report Number (EPA/600/C-03/008)
USDA-ARS Report Number (ARS/152432)
Completed:  September 1, 2003

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