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Identification Information
Title: National Wetlands Inventory - Wetlands, Southeast Alaska
Originator: U.S. Fish and Wildlife Service
Publication Place: Washington, D.C.
Publisher: U.S. Fish and Wildlife Service, Division of Habitat and Resource Conservation
Publication Date: 20120924
Website URL: http://seakgis.alaska.edu/data/SE_AK_Wetlands.zip
Resource(Server) URL: http://seakgis03.alaska.edu/rest/services/Wetlands/Wetlands_NWI/MapServer
Abstract: This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the Alaska, United States. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service's Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps.
Purpose: The present goal of the Service is to provide the citizens of the United States and its Trust Territories with current geospatially referenced information on the status, extent, characteristics and functions of wetlands, riparian, deepwater and related aquatic habitats in priority areas to promote the understanding and conservation of these resources.
Progress: Completed
Frequency: Unknown
Time Period of Content
Date Range
Begin Date: 19770101
End Date: present
Currentness: ground condition
West Bounding Longitude: -141.907189
East Bounding Longitude: -129.453177
North Bounding Latitude: 60.380844
South Bounding Latitude: 54.293024
Zoom to the resource envelope
Point of Contact
Organization: U.S. Fish and Wildlife Service
Contact Position: Wetlands Database Administrator
Address Type: mailing and physical
Address: 505 Science Drive
City: Madison
State: WI
Postal Code: 53711
Telephone: 608-238-9333
Fax: 608-238-9334
Email: wetlands_team@fws.gov
Browse Graphic
Browse Graphic URL: http://seakgis.alaska.edu/data/thumbnails/SE_AK_Wetlands.jpg
Browse Graphic Caption: Regional overview of the dataset.
Browse Graphic Type: JPEG
Constraints
Access: None
Use: None. Acknowledgement of the U.S. Fish and Wildlife Service and (or) the National Wetlands Inventory would be appreciated in products derived from these data
Theme Keywords
Theme Reference: None
Theme Topics: Deepwater habitats, Swamps, marshes, bogs, fens, Hydrography, Wetlands, Surface water
Keywords
Theme Reference: ISO 19115 Topic Categories
Theme Keywords: biota
Place Keyword Thesaurus: None
Place Keyword: United States, Alaska
Data Quality Information
Logical Consistency Report: Polygon and chain-node topology are present. Every polygon has a label.
Completeness Report: This data set represents the extent of wetlands and deepwater habitats that can be determined with the use of remotely sensed data and within the timeframe for which the maps were produced. Wetlands are shown in Alaska, United States. The accuracy of image interpretation depends on the quality of the imagery, the experience of the image analysts, the amount and quality of the collateral data, and the amount of ground truth verification work conducted. There is a margin error inherent in the use of imagery, thus detailed on-the-ground inspection of any particular site, may result in revision of the wetland boundaries or classification, established through image analysis. Wetlands or other mapped features may have changed since the date or the imagery and/or field work. There may be occasional differences in polygon boundaries or classifications between the information depicted on the map and the actual conditions on site.
Processing Steps
Step 1 Process Description: Original stable base hard copy maps of wetland and deepwater habitats were created based on USGS state and quadrangle boundaries. These maps were converted to digital files using various software packages (WAMS, ARC and others). The digital files were stored as ESRI Import/Export files corresponding to a single 1:24,000 USGS quadrangle. These digital files were imported and converted to ESRI Coverage format and checked for topological and attribute errors. All coverages were converted from a UTM map projection to an Alber's Equal Area map projection and the horizontal datum was converted from NAD27 to NAD83 were necessary. Polygons attributed as "Uplands" were removed from the dataset and polygons were merged at quadrangle boundaries where the quadrangle line divided polygons with the same attribute. The data was loaded into a seamless SDE geodatabase for the conterminous United States. These steps were conducted using both Arc Macro Language (AML) and ArcMap editing tools. All point data from the original ESRI Coverages were buffered by 11.28 meters (1/10 of an acre) and incorporated into this polygon feature class. Linear features from the original ESRI Coverages were merged at quadrangle boundaries where the quadrangle line divided lines with the same attribute. Linear data is stored in a separate feature class. Further data improvements included the conversion of all old wetland codes that contained 'OW' to the new code containing 'UB'. All polygons labeled as 'OUT', 'No Data' and 'NP' were removed from the database.
Step 1 Process Date: 20040101
Step 2 Process Description: The file was converted to NAD83 in geographic coordinates, and saved in geodatabase format.
Step 2 Process Date: 20040101
Step 3 Process Description: Added attributes System, Subsystem, Class, Subclass, Subclassb, Class2, Subclass2 and Modifiers based on the Wetlands-and-Deepwater-Habitats-Classification-chart.pdf found here at the USFWS NWI website, http://www.fws.gov/wetlands/Documents/Wetlands-and-Deepwater-Habitats-Mapping-Codes.pdf. Please contact the Southeast Alaska GIS Libraryhttp://seakgis.alaska.edu/contact.php with questions or edits. Dataset was clipped to the Southeast Alaska area and projected to NAD 83, State Plane Alaska Zone 1, FIPS 5001 by the Southeast Alaska GIS Library.
Step 3 Process Date: 20130129
Spatial Reference Information
Geodetic Model
Horizontal Datum Name: D North American 1983
Ellipsoid Name: GRS 1980
Semi-major Axis: 6378137.0
Denominator of Flattening Ratio: 298.257222101
Distribution Information
Distribution Liability: Although these data have been processed successfully on a computer system at the U.S. Fish and Wildlife Service, no warranty expressed or implied is made by the U.S. Fish and Wildlife Service 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. Fish and Wildlife Service in the use of these data.
Organization: U.S. Fish and Wildlife Service
Contact Position: Wetlands Database Administrator
Address Type: mailing and physical
Address: 505 Science Drive
City: Madison
State: WI
Postal Code: 53711
Telephone: 608-238-9333
Fax: 608-238-9334
Email: wetlands_team@fws.gov
Metadata Reference Information
Metadata Creation Date: 20140314
Organization: U.S. Fish and Wildlife Service
Contact Position: Wetlands Database Administrator
Address Type: mailing
Address: 555 Lester Ave.
City: Onalaska
State: WI
Postal Code: 54650
Telephone: 608-238-9333
Fax: 608-238-9334
Email: wetlands_team@fws.gov
Metadata Standard Name: FGDC Content Standard for Digital Geospatial Metadata
Metadata Standard Version: FGDC-STD-001-1998
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