ISO 19115 Topic Category
biota
boundaries
environment
location
EPA GIS Keyword Thesaurus
Ecosystem
Environment
Management
Natural Resources
Surface Water
None
Alaska
United States
US Environmental Protection Agency
Level III Ecoregions of Alaska
U.S. EPA Office of Research and Development (ORD) - National Health and Environmental Effects Research Laboratory (NHEERL)
Corvallis, OR
2012
withheld
http://edg.epa.gov
Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. The ecoregions of Alaska are a framework for organizing and interpreting environmental data for State, national, and international level inventory, monitoring, and research efforts. The map and descriptions for 20 ecological regions were derived by synthesizing information on the geographic distribution of environmental factors such as climate, physiography, geology, permafrost, soils, and vegetation. A qualitative assessment was used to interpret the distributional patterns and relative importance of these factors from place to place (Gallant and others, 1995). Numeric identifiers assigned to the ecoregions are coordinated with those used on the map of "Ecoregions of the Conterminous United States" (Omernik 1987, U.S. EPA 2010) as a continuation of efforts to map ecoregions for the United States. Additionally, the ecoregions for Alaska and the conterminous United States, along with ecological regions for Canada (Wiken 1986) and Mexico, have been combined for maps at three hierarchical levels for North America (Omernik 1995, Commission for Environmental Cooperation, 1997, 2006). A Roman numeral hierarchical scheme has been adopted for different levels of ecological regions. Level I is the coarsest level, dividing North America into 15 ecological regions. Level II divides the continent into 50 regions. At Level III, there are currently 182 ecological regions for North America. Level IV ecoregions have been developed for the conterminous United States, but Level III is the highest level available for Alaska.
Literature cited:
Commission for Environmental Cooperation Working Group, 1997, Ecological regions of North America - toward a common perspective: Montreal, Commission for Environmental Cooperation, 71 p.
Commission for Environmental Cooperation, 2006, Ecological regions of North America, Level III, Map scale 1:10,000,000, http://www.epa.gov/wed/pages/ecoregions/na_eco.htm.
Gallant, A.L., Binnian, E.F. Omernik, J.M. and Shasby, M.B., 1995, Ecoregions of Alaska: U.S. Geological Survey Professional Paper 1567.
Omernik, J.M., 1987, Ecoregions of the Conterminous United States: Annals of the Association of American Geographers, v. 77, no.1, p. 118-125.
Omernik, J.M., 1995, Ecoregions: a Framework for Managing Ecosystems: The George Wright Forum, v. 12, no. 1, p. 35-51.
U.S. Environmental Protection Agency, 2010, Level III ecoregions of the continental United States (revision of Omernik, 1987): Corvallis, Oregon, USEPA - National Health and Environmental Effects Research Laboratory, Map M-1, various scales.
Wiken, E.B., 1986, Terrestrial Ecozones of Canada: Lands Directorate, Environmental Canada Ecological Land Classification Series 19, 26 p.
Comments and questions regarding ecoregions should be addressed to Glenn Griffith, USGS, c/o US EPA., 200 SW 35th Street, Corvallis, OR 97333, (541)-754-4465, email:griffith.glenn@epa.gov Alternate: James Omernik, USGS, c/o US EPA, 200 SW 35th Street, Corvallis, OR 97333, (541)-754-4458, email:omernik.james@epa.gov
Ecoregion maps assist managers of aquatic and terrestrial resources to understand the regional patterns of the realistically attainable quality of these resources
Electronic versions of ecoregion maps and posters, as well as other ecoregion resources are available at: http://www.epa.gov/wed/pages/ecoregions.htm. Ecoregions were digitized at 1:250,000 or smaller scales and are intended for large geographic extents (i.e. states, multiple counties, or river basins). Use for smaller areas, such as individual counties or a 1:24,000 scale map boundary, is not recommended.
-180.000000
180.000000
71.405930
49.177353
None
None
Publication date
20120508
As needed
FIPS Pub 199
No Confidentiality
Standard Technical Controls
U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory (NHEERL)
Marc Weber
GIS Analyst
mailing address
200 S.W. 35th Street
Corvallis
OR
97333
(541) 754-4469
weber.marc@epa.gov
http://www.epa.gov/nheerl/
Vector
Simple
FALSE
0
TRUE
FALSE
coordinate pair
0.0000000037527980722984474
0.0000000037527980722984474
Meter
D North American 1983
GRS 1980
6378137.0
298.257222101
ak_eco_l3.shp
shapefile name
USEPA
Feature Class
0
OBJECTID
OBJECTID
OID
4
0
0
Internal feature number.
Esri
Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry.
ESRI
Coordinates defining the features.
Shape
Geometry
0
0
0
US_L3CODE
Code for Level III Ecoregion (United States)
CEC
unique code
US_L3CODE
String
10
0
0
US_L3NAME
Name for Level III Ecoregion (United States)
USEPA
unique name
US_L3NAME
String
100
0
0
NA_L3CODE
Code for Level III Ecoregion (North America)
CEC
unique code
NA_L3CODE
String
20
0
0
NA_L3NAME
Name for Level III Ecoregion (North America)
CEC
unique name
NA_L3NAME
String
100
0
0
NA_L2CODE
Code for Level II Ecoregion (North America)
CEC
unique code
NA_L2CODE
String
20
0
0
NA_L2NAME
Name for Level II Ecoregion (North America)
CEC
unique name
NA_L2NAME
String
100
0
0
NA_L1CODE
Code for Level I Ecoregion (North America)
CEC
unique code
NA_L1CODE
String
20
0
0
NA_L1NAME
Name for Level I Ecoregion (North America)
CEC
unique name
NA_L1NAME
String
100
0
0
STATE_NAME
Name of US State
USEPA
unique name
STATE_NAME
String
25
0
0
EPA_REGION
EPA Administrative Region
USEPA
1
10
EPA_REGION
SmallInteger
2
0
0
L3_KEY
US Level III Code and Name for Legend, color layer/style file
USEPA
unique code plus name
L3_KEY
String
254
0
0
NA_L3KEY
US Level III Code and Name for Legend, color layer/style file
USEPA
unique code plus name
NA_L3KEY
String
125
0
0
NA_L2KEY
NA Level II Code and Name for Legend, color layer/style file
USEPA
unique code plus name
NA_L2KEY
String
125
0
0
NA_L1KEY
Level I Code and Name for Legend, Match to Style
USEPA's color style for North America Ecoregions
unique code plus name
NA_L1KEY
String
125
0
0
Shape_Leng
Length of feature
ESRI
Positive real numbers that are automatically generated.
Shape_Leng
Double
8
0
0
Shape_Length
Shape_Length
Double
8
0
0
Length of feature in internal units.
Esri
Positive real numbers that are automatically generated.
Shape_Area
Area of feature in internal units squared.
ESRI
Positive real numbers that are automatically generated.
Shape_Area
Double
8
0
0
Ecoregions are hierarchical, with Level IV being the most detailed and Level I defining the broadest classifications. Because of this hierarchy, Level IV features include appropriate codes and names for Levels III, II, and I. Likewise, Level III features contain Levels II and I, and Level II retains Level I information. Attributes pertaining to Level IV are only available for the Conterminous United States (US_). Level III has attributes for the US and North America (NA_) while Levels II and I apply to only North America. All features are identified by State and EPA Administrative Regions, as well. Fields ending with "KEY" combine ecoregion code and name attributes for convenient legends and are linked to style and layer files containing color definitions.
none
Downloadable Data
Although these data have been processed successfully on a computer system at the Environmental Protection Agency, no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data to evaluate data set limitations, restrictions or intended use. The U.S. Environmental Protection Agency shall not be held liable for improper or incorrect use of the data described and/or contained herein.
U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory (NHEERL)
Marc Weber
GIS Analyst
mailing address
200 S.W. 35th Street
Corvallis
OR
97333
(541) 754-4469
weber.marc@epa.gov
http://www.epa.gov/nheerl/
20120502
20160502
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory (NHEERL)
Marc Weber
GIS Analyst
mailing address
200 S.W. 35th Street
Corvallis
OR
97333
(541) 754-4469
weber.marc@epa.gov
http://www.epa.gov/nheerl/
Although ecoregion polygons and attributes have been checked for accuracy, some errors may remain. Polygons along state borders were reviewed and updated, May 2010. ARC/INFO software is used to create and maintain topological relationships.
Unknown
Data were collected using methods that have unknown accuracy (EPA National Geospatial Data Policy [NGDP] Accuracy Tier 10). For more information, please see EPA's NGDP at http://epa.gov/geospatial/policies.html
1995
1) U.S.G.S. topographic maps, DEMs, and other base maps are used to delineate and digitize ecoregions to produce georeferenced electronic files.
1995
2) Digitized maps are joined together and errors along the edges are resolved.
1995
3) Topology is established and the maps are reviewed for accuracy and completeness. Corrections are made as needed and topology regenerated.
1995
4) Attributes are added.
1995
5) QA
2010
6) Attributes and polygons updated to be consistent with seamless US geodatabase.
2010
7) Topology errors removed.
2010
8) Final QA
2012
9) metadata
Esri ArcGIS 10.2.1.3497
AK_EcoRegion13
AK_EcoRegion13
002
Projected
GCS_North_American_1983
Linear Unit: Meter (1.000000)
NAD_1983_Alaska_Albers
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File Geodatabase Feature Class
dataset
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