Level III Ecoregions of Alaska
Level III Ecoregions of Alaska
FGDC Metadata
DescriptionSpatialData StructureData QualityData SourceData DistributionMetadata
+ Resource Description
Citation
Information used to reference the data.
Title: Level III Ecoregions of Alaska
Originators: US Environmental Protection Agency
Publisher: U.S. EPA Office of Research and Development (ORD) - National Health and Environmental Effects Research Laboratory (NHEERL)
Publication place: Corvallis, OR
Publication date: 2012
Description
A characterization of the data, including its intended use and limitations.
Abstract:
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
Purpose:
Ecoregion maps assist managers of aquatic and terrestrial resources to understand the regional patterns of the realistically attainable quality of these resources
Supplemental information:
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. 
Point Of Contact
Contact information for the individual or organization that is knowledgeable about the data.
Person: Marc Weber
Organization: U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory (NHEERL)
Position: GIS Analyst
Phone: (541) 754-4469
Email: weber.marc@epa.gov
Instructions:
http://www.epa.gov/nheerl/
Address type: mailing address
Address:
200 S.W. 35th Street
City: Corvallis
State or Province: OR
Postal code: 97333
Time Period of Data
Time period(s) for which the data corresponds to the currentness reference.
Date: 20120508
Currentness reference:
Publication date
Status
The state of and maintenance information for the data.
Data status: Complete
Update frequency: As needed
Key Words
Words or phrases that summarize certain aspects of the data.
Theme:
Keywords: biota, boundaries, environment, location
Keyword thesaurus: ISO 19115 Topic Category
Theme:
Keywords: Ecosystem, Environment, Management, Natural Resources, Surface Water
Keyword thesaurus: EPA GIS Keyword Thesaurus
Place:
Keywords: Alaska, United States
Keyword thesaurus: None
Data Access Constraints
Restrictions and legal prerequisites for accessing or using the data after access is granted.
Access constraints:
None
Use constraints:
None
Data Security Information
Handling restrictions imposed on the data because of national security, privacy or other concerns.
Security classifiction system: FIPS Pub 199
Security classification: No Confidentiality
Security handling: Standard Technical Controls
+ Spatial Reference Information
Horizontal Coordinate System
Reference system from which linear or angular quantities are measured and assigned to the position that a point occupies.
Coordinate System Details
Map projection
Map projection name: Albers Conical Equal Area (NAD83 Alaska Albers)
Standard parallel: 55.0
Standard parallel: 65.0
Longitude of central meridian: -154.0
Latitude of projection origin: 50.0
False easting: 0.0
False northing: 0.0
Planar Coordinate Information
Planar coordinate encoding method: coordinate pair
Coordinate representation:
Abscissa resolution: 0.0000000037527980722984474
Ordinate resolution: 0.0000000037527980722984474
Planar distance units: Meter
Geodetic model
Horizontal datum name: D North American 1983
Ellipsoid name: GRS 1980
Semi-major axis: 6378137.0
Denominator of flattening ratio: 298.257222101
Spatial Domain
The geographic areal domain of the data that describes the western, eastern, northern, and southern geographic limits of data coverage.
Bounding Coordinates
In Unprojected coordinates (geographic)
BoundaryCoordinate
West-180.000000 (longitude)
East180.000000 (longitude)
North71.405930 (latitude)
South49.177353 (latitude)
+ Data Structure and Attribute Information
Overview
Summary of the information content of the data, including other references to complete descriptions of entity types, attributes, and attribute values for the data.
Entity and attribute overview:
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.
Entity and attribute detailed citation:
none
Direct spatial reference method: Vector
Attributes of ak_eco_l3.shp
Detailed descriptions of entity type, attributes, and attribute values for the data.
Description:
shapefile name
Source:
USEPA
Attributes
FID
Definition:
Internal feature number.
Attribute values: Sequential unique whole numbers that are automatically generated.
Attribute definition source:
ESRI
Shape
Definition:
Feature geometry.
Attribute values: Coordinates defining the features.
Attribute definition source:
ESRI
US_L3CODE
Definition:
Code for Level III Ecoregion (United States)
Attribute values: unique code
Attribute definition source:
CEC
US_L3NAME
Definition:
Name for Level III Ecoregion (United States)
Attribute values: unique name
Attribute definition source:
USEPA
NA_L3CODE
Definition:
Code for Level III Ecoregion (North America)
Attribute values: unique code
Attribute definition source:
CEC
NA_L3NAME
Definition:
Name for Level III Ecoregion (North America)
Attribute values: unique name
Attribute definition source:
CEC
NA_L2CODE
Definition:
Code for Level II Ecoregion (North America)
Attribute values: unique code
Attribute definition source:
CEC
NA_L2NAME
Definition:
Name for Level II Ecoregion (North America)
Attribute values: unique name
Attribute definition source:
CEC
NA_L1CODE
Definition:
Code for Level I Ecoregion (North America)
Attribute values: unique code
Attribute definition source:
CEC
NA_L1NAME
Definition:
Name for Level I Ecoregion (North America)
Attribute values: unique name
Attribute definition source:
CEC
STATE_NAME
Definition:
Name of  US State
Attribute values: unique name
Attribute definition source:
USEPA
EPA_REGION
Definition:
EPA Administrative Region
Attribute domain range
RangeValue
Minimum1
Maximum10
Attribute definition source:
USEPA
L3_KEY
Definition:
US Level III Code and Name for Legend, color layer/style file
Attribute values: unique code plus name
Attribute definition source:
USEPA
NA_L3KEY
Definition:
US Level III Code and Name for Legend, color layer/style file
Attribute values: unique code plus name
Attribute definition source:
USEPA
NA_L2KEY
Definition:
NA Level II Code and Name for Legend, color layer/style file
Attribute values: unique code plus name
Attribute definition source:
USEPA
NA_L1KEY
Definition:
Level I Code and Name for Legend, Match to Style
Attribute values: unique code plus name
Attribute definition source:
USEPA's color style for North America Ecoregions
Shape_Leng
Definition:
Length of feature
Attribute values: Positive real numbers that are automatically generated.
Attribute definition source:
ESRI
Shape_Area
Definition:
Area of feature in internal units squared.
Attribute values: Positive real numbers that are automatically generated.
Attribute definition source:
ESRI
SDTS Feature Description
Description of point and vector spatial objects in the data using the Spatial Data Transfer Standards (SDTS) terminology.
Spatial data transfer standard (SDTS) terms
Feature class
Type: GT-polygon composed of chains
Count: 367
+ Data Quality and Accuracy Information
General
Information about the fidelity of relationships, data quality and accuracy tests, omissions, selection criteria, generalization, and definitions used to derive the data.
Logical consistency report:
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.
Completeness report:
Unknown
Positional Accuracy
Accuracy of the positional aspects of the data.
Horizontal accuracy report:
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
+ Data Source and Process Information
Process Steps
Information about events, parameters, tolerances and techniques applied to construct or derive the data.
Process step information
Process Step 1
Process description:
1) U.S.G.S. topographic maps, DEMs, and other base maps are used to delineate and digitize ecoregions to produce georeferenced electronic files.
Process date: 1995
Process Step 2
Process description:
2) Digitized maps are joined together and errors along the edges are resolved.
Process date: 1995
Process Step 3
Process description:
3) Topology is established and the maps are reviewed for accuracy and completeness. Corrections are made as needed and topology regenerated.
Process date: 1995
Process Step 4
Process description:
4) Attributes are added.
Process date: 1995
Process Step 5
Process description:
5) QA
Process date: 1995
Process Step 6
Process description:
6) Attributes and polygons updated to be consistent with seamless US geodatabase.
Process date: 2010
Process Step 7
Process description:
7) Topology errors removed.
Process date: 2010
Process Step 8
Process description:
8) Final QA
Process date: 2010
Process Step 9
Process description:
9) metadata
Process date: 2012
+ Data Distribution Information
General
Description of the data known by the party from whom the data may be obtained, liability of party distributing data, and technical capabilities required to use the data.
Resource description:
Downloadable Data
Distribution liability:
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.
Distribution Point of Contact
Contact information for the individual or organization distributing the data.
Organization: U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory (NHEERL)
Person: Marc Weber
Position: GIS Analyst
Phone: (541) 754-4469
Email: weber.marc@epa.gov
Instructions:
http://www.epa.gov/nheerl/
Address type: mailing address
Address:
200 S.W. 35th Street
City: Corvallis
State or Province: OR
Postal code: 97333
+ Metadata Reference
Metadata Date
Dates associated with creating, updating and reviewing the metadata.
Last updated: 20120502
Future metadata review date: 20160502
Metadata Point of Contact
Contact information for the individual or organization responsible for the metadata information.
Person: Marc Weber
Organization: U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory (NHEERL)
Position: GIS Analyst
Phone: (541) 754-4469
Email: weber.marc@epa.gov
Instructions:
http://www.epa.gov/nheerl/
Address type: mailing address
Address:
200 S.W. 35th Street
City: Corvallis
State or Province: OR
Postal code: 97333
Metadata Standards
Description of the metadata standard used to document the data and reference to any additional extended profiles to the standard used by the metadata producer.
Standard name: FGDC Content Standard for Digital Geospatial Metadata
Standard version: FGDC-STD-001-1998
FGDC Plus Metadata Stylesheet
Stylesheet: FGDC Plus Stylesheet
File name: FGDC Plus.xsl
Version: 2.3
Description: This metadata is displayed using the FGDC Plus Stylesheet, which is an XSL template that can be used with ArcGIS software to display metadata. It displays metadata elements defined in the Content Standard for Digital Geospatial Metadata (CSDGM) - aka FGDC Standard, the ESRI Profile of CSDGM, the Biological Data Profile of CSDGM, and the Shoreline Data Profile of CSDGM. CSDGM is the US Federal Metadata standard. The Federal Geographic Data Committee originally adopted the CSDGM in 1994 and revised it in 1998. According to Executive Order 12096 all Federal agencies are ordered to use this standard to document geospatial data created as of January, 1995. The standard is often referred to as the FGDC Metadata Standard and has been implemented beyond the federal level with State and local governments adopting the metadata standard as well. The Biological Data Profile broadens the application of the CSDGM so that it is more easily applied to biological data that are not explicitly geographic (laboratory results, field notes, specimen collections, research reports) but can be associated with a geographic location. Includes taxonomical vocabulary. The Shoreline Data Profile addresses variability in the definition and mapping of shorelines by providing a standardized set of terms and data elements required to support metadata for shoreline and coastal data sets. The FGDC Plus Stylesheet includes the Dublin Core Metadata Element Set. It supports W3C DOM compatible browsers such as IE7, IE6, Netscape 7, and Mozilla Firefox. It is in the public domain and may be freely used, modified, and redistributed. It is provided "AS-IS" without warranty or technical support.
Instructions: On the top of the page, click on the title of the dataset to toggle opening and closing of all metadata content sections or click section links listed horizontally below the title to open individual sections. Click on a section name (e.g. Description) to open and close section content. Within a section, click on a item name (Status, Key Words, etc.) to open and close individual content items. By default, the Citation information within the Description section is always open for display.
Download: FGDC Plus Stylesheet is available from the ArcScripts downloads at www.esri.com.