Citation:

Hall, R. K., J M. Omernik, A. J. Woods, S. A. Bryce, AND D T. Heggem. CLUSTER ANALYSIS OF GREAT BASIN ECOREGIONS USING R-EMAP STREAM DATA. Presented at Environmental Monitoring and Assessment Program (EMAP) Symposium 2004, Newport, RI, May 3-7, 2004.

Impact/Purpose:

There are four basic objectives of the project:

Demonstrate the application of a comparative landscape assessment in analyzing the vulnerability of surface and coastal water conditions to declines based on landscape conditions (as estimated by landscape indicators as demonstrated in the mid-Atlantic landscape atlas) in western environments;

Develop and apply landscape assessment approaches relative to specific issues, including an ability to prioritize the vulnerability of areas relative to the Clean Water Act 303(d) designations; Quantify relationships between landscape conditions (as measured by landscape indicators) and surface and coastal waters in the west to reduce the uncertainty in comparative landscape assessments, and issue-specific, landscape assessments (e.g., Total Maximum Daily Load (TMDLs);

Complete a west-wide, comparative landscape assessment relative to surface and coastal water vulnerability;

Transfer landscape assessment technologies to Regional Offices so that they can conduct landscape assessments at many scales.

Description:

Ecological regions ( ecoregions ) are defined as areas of relative homogeneity in ecosystem type, quality and quantity of environmental resources. Ecoregions are identified by analyzing biotic and abiotic geographic patterns, which are natural and human related. Parameters used in classifying these spatial patterns are climate, physiography, geology, soil, vegetation and land use (i.e. human influences). Human influences will accelerate changes in the ecosystem character. Over time ecoregions will develop patterns characteristic of human disturbance and alterations. The objective of this study is to test the viability of ecoregions using environmental data from the U .S. EP A Region IX Regional Environmental Monitoring and Assessment Program (R- EMAP) project in the Humboldt Basin, Nevada, to define areas impacted by human activity. Group averaging cluster analysis of environmental data indicates increasing nutrients and metal concentrations towards the basins as a result of upstream land use ( extensive grazing, agricultural pressure, mining). Phosphorus, arsenic and sulfate concentrations are indicative of the general geology, and the spatial distribution of land cover and land use (mining and agriculture) patterns. Variability, of water and sediment chemistry and benthic invertebrate community, within an ecoregion is associated with land use characteristics.

Record Details: