Western United States Landscape Characterization
The Environmental Monitoring and Assessment Program (EMAP) is proposing an ambitious agenda to assess the status of aquatic resources in a 12-State area of the western United States by 2003.
Additionally, EMAP is proposing to access landscape conditions as they relate to aquatic resources with the aim of extending probability-based sampling to all streams, estuaries, and coastal waters across the western US. Five research and development activities are critical to the completion of this unprecedented landscape assessment: (1) acquisition and assembly of landscape databases, (2) developing new remote sensing approaches to detect watershed-scale stressors, (3) identifying and developing landscape indicators, (4) quantifying relationships between aquatic resource conditions and landscape indicators, and (5) developing and implementing assessment methodologies. Results of the assessment should help environmental managers target those areas where aquatic resources are most vulnerable to decline in conditions based on watershed-scale, landscape conditions. This poster presentation gives the results of the first application of landscape ecological indicators to selected areas in the western United States.
Indicator Development for Landscape-Level Aquatic Ecological Vulnerability Assessment in Western United States [PDF, Poster 1 pp., 739 KB, About PDF]
Initial landscape assessment efforts for the U.S. EPA Environmental Monitoring and Assessment Programs Western Pilot focused on improving and testing landscape indicators previously developed for the mid-Atlantic region of the United States.
Landscape indicators representing three general categories were developed for six study areas in the western United States. These categories represented indicators derived from (1) single spatial databases, (2) intersections of two or more spatial databases, and (3) models. Study areas were chosen to represent a variety of ecosystems distinct from those in the mid-Atlantic region and encompassed multiple watersheds. An intensive human use index was developed to assess the relative distribution of dramatic anthropogenic land cover change caused by urbanization and agricultural development. The presence of agriculture on steep slopes was used as an initial indicator of upland soil loss potential. Dasymetric mapping of population density was used to provide a more realistic representation of human occupancy of the landscape than simple mapping of census data. Indicator results were highly skewed with many values near zero. Several areas (Willamette Valley in northwestern Oregon, viticultural areas in northern California, and the coastal plains of southern California) had high scores for all indicators and were expected to have the most degraded aquatic resource conditions. Needed improvements in the indicators presented are also discussed.