Omernik's Ecoregion boundaries for SAA SAA Version 3.0 Version Release Date: 3/21/96 --------------------------------------------------------------------------- -------------------------------------------------------------------------- Identification Information Data Layer Name: omernik Description: This data layer includes boundaries of Omernik's ecoregions for the Vicinity of the Southern Appalachian Assessment (SAA) Study Area Keywords: Omernik, ecoregion, ecology, vegetation, landscape Citation: none Native Data Set Environment: Unix; Arc/Info 7.0.3 pathname: Scale: compiled at 1:3,168,000; digitized at 1:2,500,000 File Format: ARC/INFO Polygon coverage Use Restrictions: none Access Restrictions: none -------------------------------------------------------------------------- -------------------------------------------------------------------------- Spatial Reference Information Spatial Reference Information Datum: North American Datum 1983 (NAD83) Precision: single Projection: Albers Equal Area Units: meters Spheroid: WGS-84 1st Std Parallel: 34 00 00 2nd Std Parallel: 38 00 00 Central Meridian: -82 00 00 Origin: 33 00 00 False Northing: 0.0 False Easting: 0.0 Extent: West Bounding Coord.: -428494.531 East Bounding Coord.: 359343.562 North Bounding Coord.: 739719.000 South Bounding Coord.: 10488.265 Distance Resolution: unknown Vertical Resolution: n/a -------------------------------------------------------------------------- ---------------------------------------------------------------------------- Data Quality Information Thematic Accuracy: unknown Confidence: unknown Accuracy Method: James Omernik of the U.S. Environmental Protection Agency's Environmental Research Laboratory-Corvallis delineated the original ecoregion boundaries based on land-surface form, potential natural vegetation, land use, and soil classifications. This original coverage eventually became known throughout EPA as Omernik's subecoregions. Omernik subsequently created another ecoregion map by aggregating some of the subecoregions; he claimed that his original premise was flawed and asked that the present ecoregion map be used and not the original subecoregion map. Unfortunately, the original subecoregion map had already been widely distributed throughout EPA and is still in use. This particular ecoregion coverage seems to be a hybrid of the original subecoregion map. It does not correspond to the most current version of Omernik's ecoregion coverage which is available from ERL-Corvallis. Horizontal Accuracy: unknown Confidence: unknown Accuracy Method: unknown Vertical Accuracy: n/a Logical Consistency: Completeness: ---------------------------------------------------------------------------- --------------------------------------------------------------------------- Source Information Source Material: Digitized Omernik's Ecoregions of the United States at a scale of 1:2,500,000. Organization: EPA ERL-Corvallis Date: unknown Distance Resolution: unknown Contribution: Ecoregion boundaries and codes --------------------------------------------------------------------------- ------------------------------------------------------------------------- Processing History Information Process Description: 1. The original Omernik ecoregion coverage was created by many people but there is no detailed documentation on how the coverage was created or what standards, if any, were used. The original coverage was compiled at 1:3,168,000 scale and digitized at 1:2,500,000 scale with Root Mean Squared error of .003. 2. SAA obtained a version of Omernik's ecoregion coverage from EPA (version unknown), projected the coverage into Albers Equal Area projection (parameters in the Spatial Reference Section), and clipped the coverage to the SAA CLIPBOX. ------------------------------------------------------------------------- ----------------------------------------------------------------- Entity/Attribute Information Entity: OMERNIK.PAT Definition: Omernik's Ecoregion Polygons Attributes: COL ITEM NAME WDTH OPUT TYP N.DEC DEFINITION 1 AREA 4 12 F 3 Area in square meters per polygon 5 PERIMETER 4 12 F 3 Perimeter in meters per polygon 9 OMERNIK# 4 5 B - Internal polygon identification number 13 OMERNIK-ID 4 5 B - User-defined polygon identification number 17 ECO 4 5 B - Omernik's ecoregion code 21 ECOREGION 32 32 C - Omernik's ecoregion name Entity: OMERNIK.TIC Definition: OMERNIK Coverage Control Tics Attributes: COL ITEM NAME WDTH OPUT TYP N.DEC DEFINITION 1 IDTIC 4 5 B - User-defined tic identification number 5 XTIC 4 12 F 3 X coordinate for tic 9 YTIC 4 12 F 3 Y coordinate for tic Entity: OMERNIK.BND Definition: OMERNIK Coverage Bounding Coordinates Attributes: COL ITEM NAME WDTH OPUT TYP N.DEC DEFINITION 1 XMIN 4 12 F 3 Minimum x-coordinate in coverage 5 YMIN 4 12 F 3 Minimum y-coordinate in coverage 9 XMAX 4 12 F 3 Maximum x-coordinate in coverage 13 YMAX 4 12 F 3 Maximum y-coordinate in coverage ------------------------------------------------------------- ---------------------------------------------------------------- Status Information Data Set Status: Available Release Date: 3/21/96 ---------------------------------------------------------------- ---------------------------------------------------------------- Metadata Reference Information Date: 3/20/96 Review Date: Contact: Karl A. Hermann National Biological Service Cooperative University of Tennessee 17 Ridgeway Road Norris, TN 37828 samab@utk.edu (423)-632-1452 ---------------------------------------------------------------- ---------------------------------------------------------------- Distribution Information Distribution Contact: Karl A. Hermann National Biological Service Cooperative University of Tennessee 17 Ridgeway Road Norris, TN 37828 samab@utk.edu (423)-632-1452 Distribution Liability: File Compression Technique: UNIX compress, Arc/Info export format Transfer Size: --------------------------------------------------------------- --------------------------------------------------------------- Contact Information Contact Person: Karl A. Hermann Contact Mail Address: National Biological Service Cooperative University of Tennessee 17 Ridgeway Road Norris, TN 37828 Contact Phone: (423)-632-1452 Contact Fax: (423)-632-1612 Contact email: samab@www.lib.utk Home Page for Updates: http://www.lib.utk.edu/samab ---------------------------------------------------------------- ----------------------------------------------------------------