EPA Environmental Dataset Gateway


Open/Close section Identification Information
Title: EPA Level III Ecoregions
Abstract: The ecoregions shown here have been derived from Omernik (1987) and from refinements of Omernik's framework that have been made for other projects. These ongoing or recently completed projects, conducted in collaboration with the U.S. EPA regional offices and with state resource management agencies, involve refining ecoregions, defining subregions, and locating sets of reference sites. Designed to serve as a spatial framework for environmental resource management, ecoregions denote areas within which ecosystems (and the type, quality, and quantity of environmental resources) are generally similar. The most immediate needs are to develop regional biological criteria and water quality standards and to set management goals for nonpoint source pollution. The approach used to compile this map is based on the premise that ecological regions can be identified through the analysis of the patterns and the composition of biotic and abiotic phenomena that affect or reflect differences in ecosystem quality and integrity (Wiken 1986; Omernik 1987, 1995). These phenomena include geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology. The relative importance of each characteristic varies from one ecological region to another regardless of the hierarchical level. Because of possible confusion with other meanings of terms for different levels of ecologic regions, a Roman numeral classification scheme has been adopted for this effort. Level I is the coarsest level, dividing North America into 15 ecological regions whereas at Level II the continent is subdivided into 52 classes. Level III is the hierarchical level shown on this map. For portions of the United States the ecoregions have been further subdivided to level IV. The applications of the ecoregions are explained in Gallant et al. (1989) and in reports and publications from the state and regional projects. For additional information, contact James M. Omernik, U.S. EPA National Health and Environmental Effects Laboratory (NHEERL), 200 SW 35th St., Corvallis, OR 97333 (phone: 541-754-4458).
Purpose: Assist managers of aquatic and terrestrial resources in understanding the regional patterns of the realistically attainable quality of these resources.
Open/Close section Distribution Information
Resource(Server) URL: http://www.epa.gov/geospatial/
Download URL: https://edg.epa.gov
Reference URL: http://www.epa.gov/wed/pages/ecoregions.htm
Website URL: ftp://ftp.epa.gov/wed/ecoregions/
Open/Close section Time Period of Content
Publication Date: 2003
Progress: 2003
Open/Close section Single Date
Date: 1986-2/03
Open/Close section Spatial Domain
West Bounding Longitude: -127.841952
East Bounding Longitude: -65.38508
North Bounding Latitude: 51.54021
South Bounding Latitude: 22.877533
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Open/Close section Constraints
License https://edg.epa.gov/EPA_Data_License.htm
Access: None
Use: for use at 1:250,000 or smaller scales
Open/Close section Theme Keywords
Theme Topics: Level III ecoregions
Open/Close section Contact Information
Originator: US Environmental Protection Agency
Email: r2gisdata@epa.gov
Address Type: mailing and physical address
City: New York
State: NY
Postal Code: 10007-1866
Telephone: (212) 637-3596
Open/Close section Metadata Reference Information
Metadata Date Stamp: 2009-01-15
Metadata Standard Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata Standard Version: FGDC-STD-001-1998