to the National Atlas Home page
About | Fact Sheets | Contact Us | Partners | Products | Site Map | FAQ | Help | Follow us on Twitter 
Part of Project LogoAgricultureBiologyBoundariesClimateEnvironmentGeologyGovernmentHistoryMappingPeopleTransportationWater
to the Interactive Map MakerMap LayersPrintable MapsWall MapsDynamic MapsArticlesMapping Professionals

Omernik's Level III Ecoregions of the Continental United States

Metadata also available as - [Questions & Answers] - [Parseable text] - [XML] - [DIF]

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: U.S. Environmental Protection Agency
Publication_Date: 200506
Title: Omernik's Level III Ecoregions of the Continental United States
Publication_Information:
Publication_Place: Reston, VA
Publisher: National Atlas of the United States
Online_Linkage:
<http://nationalatlas.gov/atlasftp.html?openChapters=chpbio#chpbio>
Description:
Abstract:
This map layer shows Omernik's Level III ecoregions, derived from a 1:7,500,000 map created by J.M. Omernik in 1987 and from refinements of Omernik's framework that were made for other projects. Ecoregions describe areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. Omernik's ecoregions are based on the premise that a hierarchy of ecological regions can be identified through the analysis of the patterns and the composition of both living and nonliving phenomena, such as geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology, that affect or reflect differences in ecosystem quality and integrity. All the characteristics are considered when determining ecoregions, but the relative importance of each characteristic may vary from one ecoregion to another. Level III is the most detailed level available nationally for this system of ecoregions.
Purpose:
These data are intended for geographic display and analysis at the national level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:7,500,000-scale data. No responsibility is assumed by the National Atlas of the United States in the use of these data.
Supplemental_Information:
Detailed descriptions of the ecological regions represented in this map layer are available from the U.S. Environmental Protection Agency (EPA), Western Ecology Division at: <http://www.epa.gov/wed/pages/ecoregions/level_iii.htm>. EPA also offers data of Omernik's Level III Ecoregions on the same site; the file includes the same ecoregions as are available through the National Atlas but uses EPA shorelines and State boundaries.

A bibliography of ecoregion/biocriteria publications, called Ecoomr_Biblio.txt, is bundled with the downloadable data. Each reference in the bibliography has a code; the codes are used for any citations in this metadata file.

Ecoregions denote areas of general similarity in ecosystems and the type, quantity, and quality of environmental resources; they are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components. By recognizing the spatial differences in the capacities and potentials of ecosystems, ecoregions stratify the environment by its probable response to disturbance (BR-1-98). These general purpose regions are critical for structuring and implementing ecosystem management strategies across Federal agencies, State agencies, and nongovernmental organizations that are responsible for different types of resources within the same geographic areas (OM-1-00, OM-1-04).

The approach used to compile these ecoregions is based on the premise that ecological regions are hierarchical and can be identified through the analysis of the spatial patterns and composition of biotic and abiotic phenomena that affect or reflect differences in ecosystem quality and integrity (WI-1-86, OM-1-87, OM-1-95, OM-1-04). These phenomena include geology, physiography, vegetation, climate, soils, land use, wildlife, water quality, and hydrology. In the regionalization process, the full range of characteristics is examined and integrated at each scale or level of resolution. The relative importance of each characteristic varies from one ecological region to another regardless of the hierarchical level. Level I is the coarsest level of the hierarchy, dividing North America into 15 ecological regions. Level II divides the continent into 52 regions (CE-1-97). At level III, the continental United States contains 104 ecoregions, with the conterminous United States having 84 (US-1-03). More detailed level IV ecoregions have been delineated, or are in the process of being mapped, for approximately 85 percent of the conterminous United States.

Since 1994, when the National Interagency Technical Team (NITT) was formed to develop a common framework of ecological regions (MM-1-01), efforts have been made to include all of the major federal resource management agencies in the level IV ecoregion mapping projects. The goal of each of these collaborative projects has been to attain consensus across agencies and ultimately to develop a consistent ecoregion framework for the entire nation.

Because the collaborative projects to map level IV ecoregions often result in refined level III boundaries, the map of level III ecoregions is periodically revised. Likewise, much of the recent work to refine level III boundaries and define level IV ecoregions has resulted in slight differences between these two levels and the coarser level I and II regions mapped earlier by the CEC.

Level IV ecoregions data and maps can be accessed through the Environmental Protection Agency Level IV Ecoregions page at <http://www.epa.gov/wed/pages/ecoregions/level_iv.htm>.

Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 200302
Currentness_Reference: Publication date of primary source material
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Irregular
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: 178
East_Bounding_Coordinate: -66
North_Bounding_Coordinate: 53
South_Bounding_Coordinate: 25
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: biota
Theme_Keyword: environment
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Ecoregions
Theme_Keyword: Omernik's ecoregions
Theme_Keyword: Ecological regions
Theme_Keyword: Ecosystems
Theme_Keyword: Regional ecology
Theme_Keyword: Ecosystem geography
Theme_Keyword: Mapping
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: United States
Place:
Place_Keyword_Thesaurus:
U.S. Department of Commerce, 1987, Codes for the Identification of the States, the District of Columbia and the Outlying Areas of The United States, and Associated Areas (FIPS 5-2): Washington, DC, National Institute of Standards and Technology.
Place_Keyword: Alabama
Place_Keyword: Alaska
Place_Keyword: Arizona
Place_Keyword: Arkansas
Place_Keyword: California

Place_Keyword: Colorado
Place_Keyword: Connecticut
Place_Keyword: Delaware
Place_Keyword: District of Columbia
Place_Keyword: Florida
Place_Keyword: Georgia
Place_Keyword: Idaho
Place_Keyword: Illinois
Place_Keyword: Indiana
Place_Keyword: Iowa
Place_Keyword: Kansas
Place_Keyword: Kentucky
Place_Keyword: Louisiana
Place_Keyword: Maine
Place_Keyword: Maryland
Place_Keyword: Massachusetts
Place_Keyword: Michigan
Place_Keyword: Minnesota
Place_Keyword: Mississippi
Place_Keyword: Missouri
Place_Keyword: Montana
Place_Keyword: Nebraska
Place_Keyword: Nevada
Place_Keyword: New Hampshire
Place_Keyword: New Jersey
Place_Keyword: New Mexico
Place_Keyword: New York
Place_Keyword: North Carolina
Place_Keyword: North Dakota
Place_Keyword: Ohio
Place_Keyword: Oklahoma
Place_Keyword: Oregon
Place_Keyword: Pennsylvania
Place_Keyword: Rhode Island
Place_Keyword: South Carolina
Place_Keyword: South Dakota
Place_Keyword: Tennessee
Place_Keyword: Texas
Place_Keyword: Utah
Place_Keyword: Vermont
Place_Keyword: Virginia
Place_Keyword: Washington
Place_Keyword: West Virginia
Place_Keyword: Wisconsin
Place_Keyword: Wyoming

Access_Constraints: None
Use_Constraints:
None. Acknowledgment of the U.S. Environmental Protection Agency and (or) the National Atlas of the United States of America would be appreciated in products derived from these data.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: James M. Omernik
Contact_Organization: U.S. Environmental Protection Agency, Western Ecology Division
Contact_Address:
Address_Type: Mailing and physical address
Address: 200 SW 35th Street
City: Corvallis
State_or_Province: OR
Postal_Code: 97333
Country: USA
Contact_Voice_Telephone: 541-754-4458
Contact_Facsimile_Telephone: 541-754-4716
Contact_Electronic_Mail_Address: omernik.james@epa.gov
Native_Data_Set_Environment: SunOS UNIX, ARC/INFO version 8.3.
Cross_Reference:
Citation_Information:
Originator: James M. Omernik
Publication_Date: 1987
Title: Ecoregions of the conterminous United States (map supplement)
Edition: 1
Geospatial_Data_Presentation_Form: Map
Series_Information:
Series_Name: Annals of the Association of American Geographers
Issue_Identification: 77(1)
Publication_Information:
Publication_Place: Washington, DC
Publisher: Association of American Geographers
Cross_Reference:
Citation_Information:
Originator: USDA Forest Service
Publication_Date: 200403
Title:
Bailey's Ecoregions and Subregions of the United States, Puerto Rico, and the U.S. Virgin Islands
Geospatial_Data_Presentation_Form: Map
Publication_Information:
Publication_Place: Reston, VA
Publisher: National Atlas of the United States
Online_Linkage:
<http://nationalatlas.gov/atlasftp.html?openChapters=chpbio#chpbio>
Online_Linkage:
<http://www.fs.fed.us/institute/ecoregions/eco_download.html>


Data_Quality_Information:
Logical_Consistency_Report:
No checks for topological consistency were performed on this map layer.
Completeness_Report:
This map layer includes Level III ecoregions information for the conterminous United States and Alaska.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Omernik, J.M.
Publication_Date: 2003
Title: Level III Ecoregions of the continental United States
Geospatial_Data_Presentation_Form: Vector digital data
Publication_Information:
Publication_Place: Corvallis, OR
Publisher: U.S. Environmental Protection Agency
Online_Linkage: <http://www.epa.gov/wed/pages/ecoregions/level_iii.htm>
Source_Scale_Denominator: 7500000
Type_of_Source_Media: Online
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 200302
Source_Currentness_Reference: Publication date
Source_Citation_Abbreviation: US Ecoregions
Source_Contribution: Spatial and attribute information

Source_Information:
Source_Citation:
Citation_Information:
Originator: Omernik, J.M.
Publication_Date: 2000
Title: Ecoregions of North America
Geospatial_Data_Presentation_Form: Vector digital data
Publication_Information:
Publication_Place: Corvallis, OR
Publisher: U.S. Environmental Protection Agency
Online_Linkage: <http://www.epa.gov/wed/pages/ecoregions/na_eco.htm>
Source_Scale_Denominator: 12500000
Type_of_Source_Media: Online
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2000
Source_Currentness_Reference: Publication date
Source_Citation_Abbreviation: NA Ecoregions
Source_Contribution: Spatial and attribute information

Source_Information:
Source_Citation:
Citation_Information:
Originator: National Atlas of the United States
Publication_Date: 200506
Title: State Boundaries of the United States
Publication_Information:
Publication_Place: Reston, VA
Publisher: National Atlas of the United States
Online_Linkage:
<http://nationalatlas.gov/atlasftp.html?openChapters=chpbound#chpbound>
Source_Scale_Denominator: 2000000
Type_of_Source_Media: Online
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 1972
Ending_Date: 2005
Source_Currentness_Reference: Ground condition
Source_Citation_Abbreviation: Atlas-States
Source_Contribution: Spatial information

Process_Step:
Process_Description:
The US Ecoregions and NA Ecoregions files were downloaded and reprojected to a Lambert Azimuthal Equal Area projection using ArcGIS 9.0. The shorelines in US Ecoregions were deleted. Alaska was clipped from in NA Ecoregions, placed in a new file, and the shorelines were deleted. The resulting files were combined along with shorelines from the Atlas-States map layer. Line work was cleaned and adjusted. The polygon attribution from US Ecoregions and NA Ecoregions was copied into the data and checked.
Source_Used_Citation_Abbreviation: US Ecoregions
Source_Used_Citation_Abbreviation: NA Ecoregions
Source_Used_Citation_Abbreviation: Atlas-States
Process_Date: 200503


Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Point_and_Vector_Object_Count: 3075


Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.000278
Longitude_Resolution: 0.000278
Geographic_Coordinate_Units: Decimal degrees
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: GRS1980
Semi-major_Axis: 6378137.0
Denominator_of_Flattening_Ratio: 298.257222


Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: Ecoregion (described by ecoomrp075.dbf)
Entity_Type_Definition:
A region that denotes an area of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. The polygons in this map layer represent Omernik Level III ecoregions.
Entity_Type_Definition_Source: National Atlas of the United States
Attribute:
Attribute_Label: Shape
Attribute_Definition: The representation of the entity in the data.
Attribute_Definition_Source: National Atlas of the United States
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Polygon
Enumerated_Domain_Value_Definition: 2-dimensional element
Enumerated_Domain_Value_Definition_Source: ESRI GIS software
Attribute:
Attribute_Label: Area
Attribute_Definition:
The size of the shape in coverage units. In the distributed file, coverage units represent square decimal degrees.
Attribute_Definition_Source: National Atlas of the United States
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.00000
Range_Domain_Maximum: 50.151550
Attribute:
Attribute_Label: Perimeter
Attribute_Definition:
The perimeter of the shape in coverage units. In the distributed file, coverage units represent decimal degrees.
Attribute_Definition_Source: National Atlas of the United States
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.00857
Range_Domain_Maximum: 261.67570
Attribute:
Attribute_Label: Ecoomrp075
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: National Atlas of the United States
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2
Range_Domain_Maximum: 3076
Attribute:
Attribute_Label: Level3
Attribute_Definition: The numeric code of the Level III ecoregion.
Attribute_Definition_Source: National Atlas of the United States
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1
Range_Domain_Maximum: 120
Attribute:
Attribute_Label: Level3_name
Attribute_Definition: The name of the Level III ecoregion.
Attribute_Definition_Source: National Atlas of the United States
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: (see table below)
Enumerated_Domain_Value_Definition:
A full description of the ecoregions can be found at <ftp://ftp.epa.gov/wed/ecoregions/us/useco_desc.doc>
 Code   Name
-------------------------------------------------------------------
 1      Coast Range
 2      Puget Lowland
 3      Willamette Valley
 4      Cascades
 5      Sierra Nevada
 6      Southern and Central California Chaparral and Oak Woodlands
 7      Central California Valley
 8      Southern California Mountains
 9      Eastern Cascades Slopes and Foothills
 10     Columbia Plateau
 11     Blue Mountains
 12     Snake River Plain
 13     Central Basin and Range
 14     Mojave Basin and Range
 15     Northern Rockies
 16     Idaho Batholith
 17     Middle Rockies
 18     Wyoming Basin
 19     Wasatch and Uinta Mountains
 20     Colorado Plateaus
 21     Southern Rockies
 22     Arizona/New Mexico Plateau
 23     Arizona/New Mexico Mountains
 24     Chihuahuan Deserts
 25     High Plains
 26     Southwestern Tablelands
 27     Central Great Plains
 28     Flint Hills
 29     Cross Timbers
 30     Edwards Plateau
 31     Southern Texas Plains
 32     Texas Blackland Prairies
 33     East Central Texas Plains
 34     Western Gulf Coastal Plain
 35     South Central Plains
 36     Ouachita Mountains
 37     Arkansas Valley
 38     Boston Mountains
 39     Ozark Highlands
 40     Central Irregular Plains
 41     Canadian Rockies
 42     Northwestern Glaciated Plains
 43     Northwestern Great Plains
 44     Nebraska Sand Hills
 45     Piedmont
 46     Northern Glaciated Plains
 47     Western Corn Belt Plains
 48     Lake Agassiz Plain
 49     Northern Minnesota Wetlands
 50     Northern Lakes and Forests
 51     North Central Hardwood Forests
 52     Driftless Area
 53     Southeastern Wisconsin Till Plains
 54     Central Corn Belt Plains
 55     Eastern Corn Belt Plains
 56     Southern Michigan/Northern Indiana Drift Plains
 57     Huron/Erie Lake Plains
 58     Northeastern Highlands
 59     Northeastern Coastal Zone
 60     Northern Appalachian Plateau and Uplands
 61     Erie Drift Plain
 62     North Central Appalachians
 63     Middle Atlantic Coastal Plain
 64     Northern Piedmont
 65     Southeastern Plains
 66     Blue Ridge
 67     Ridge and Valley
 68     Southwestern Appalachians
 69     Central Appalachians
 70     Western Allegheny Plateau
 71     Interior Plateau
 72     Interior River Valleys and Hills
 73     Mississippi Alluvial Plain
 74     Mississippi Valley Loess Plains
 75     Southern Coastal Plain
 76     Southern Florida Coastal Plain
 77     North Cascades
 78     Klamath Mountains
 79     Madrean Archipelago
 80     Northern Basin and Range
 81     Sonoran Basin and Range
 82     Laurentian Plains and Hills
 83     Eastern Great Lakes and Hudson Lowlands
 84     Atlantic Coastal Pine Barrens
 101    Arctic Coastal Plain
 102    Arctic Foothills
 103    Brooks Range
 104    Interior Forested Lowlands And Uplands
 105    Interior Highlands
 106    Interior Bottomlands
 107    Yukon Flats
 108    Ogilvie Mountains
 109    Subarctic Coastal Plains
 110    Seward Peninsula
 111    Ahklun And Kilbuck Mountains
 112    Bristol Bay-Nushagak Lowlands
 113    Alaska Peninsula Mountains
 114    Aleutian Islands
 115    Cook Inlet
 116    Alaska Range
 117    Copper Plateau
 119    Pacific Coastal Mountains
 120    Coastal Western Hemlock-Sitka Spruce Forests
Enumerated_Domain_Value_Definition_Source:
U.S. Environmental Protection Agency


Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Earth Science Information Center, U.S. Geological Survey
Contact_Address:
Address_Type: Mailing address
Address: 507 National Center
City: Reston
State_or_Province: VA
Postal_Code: 20192
Contact_Voice_Telephone: 1-888-ASK-USGS (1-888-275-8747)
Contact_Voice_Telephone: 703-648-5920
Contact_Instructions:
In addition to the address above there are other ESIC offices throughout the country. A full list of these offices is at <http://ask.usgs.gov/esic_index.html>.
Distribution_Liability:
Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made by the U.S. Geological Survey regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. No responsibility is assumed by the U.S. Geological Survey in the use of these data.

Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ESRI Shapefile
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
<http://nationalatlas.gov/atlasftp.html?openChapters=chpbio#chpbio>
Digital_Form:
Digital_Transfer_Information:
Format_Name: SDTS
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
<http://nationalatlas.gov/atlasftp.html?openChapters=chpbio#chpbio>

Fees: There is no charge for this map layer.


Metadata_Reference_Information:
Metadata_Date: 20060419
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Peg Rawson
Contact_Organization: National Atlas of the United States
Contact_Address:
Address_Type: Mailing address
Address: 12201 Sunrise Valley Drive
Address: MS-561
City: Reston
State_or_Province: VA
Postal_Code: 20192
Contact_Voice_Telephone: 703-648-4183
Contact_Electronic_Mail_Address: atlasmail@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Security_Information:
Metadata_Security_Classification_System: None
Metadata_Security_Classification: Unclassified
Metadata_Security_Handling_Description: None



 


Generated by mp version 2.8.16 on Mon May 15 13:26:29 2006