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.
Comments regarding the interpretation or classification of wetlands or deepwater habitats can be directed to the U.S. Fish and Wildlife Service, Division of Federal Program Activities, Branch of Habitat Assessment <http://www.fws.gov/duspit/contactus.htm>
These data were developed in conjunction with the publication Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. U.S. Department of the Interior, Fish and Wildlife Service, Washington, DC. FWS/OBS-79/31. Alpha-numeric map codes have been developed to correspond to the wetland and deepwater classifications described.
These spatial data are not designed to stand alone. They form topical overlays to the U.S. Geological Survey 1:24,000 or 1:25,000 scale topographic quadrangles. Note that coastline delineations were drawn to follow the extent of wetland or deepwater features as described by this project and may not match the coastline shown in other base maps.
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Arc/INFO format, this metadata file may include some Arc/INFO-specific terminology.
U.S. Fish and Wildlife Service, 200610, Wetlands: Classification of Wetlands and Deepwater Habitats of the United States. U.S. Department of the Interior, Fish and Wildlife Service, Washington, DC. FWS/OBS-79/31., U.S. Fish and Wildlife Service, Branch of Habitat Assessment, Washington, D.C..Online Links:
- \\wvs1\Clients\Accomack\Current\Data\AccomackGIS_old.gdb
This is a Vector data set. It contains the following vector data types (SDTS terminology):
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest 0.000032
Ordinates (y-coordinates) are specified to the nearest 0.000032
Planar coordinates are specified in meters
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.
| Value | Definition |
|---|---|
| Polygon | 2-dimensional element. |
Coordinates defining the features.
Coordinates defining the features.
Positive real numbers that are automatically generated.
Positive real numbers that are automatically generated.
703-358-2161 (voice)
703-358-1869 (FAX)
john_cooper@fws.gov
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.
U.S. Fish and Wildlife Service, 1977 to present, Wetlands and Deepwater Habitats of the Conterminous United States: National Wetlands Inventory Maps, U.S. Fish and Wildlife Service, Washington, D.C..
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.
Data sources used in this process:
Data sources used in this process:
Data sources used in this process:
Data sources used in this process:
Data sources used in this process:
U.S. Fish and Wildlife Serivce, National Wetlands Inventory, Various, Wetlands and Deepwater Habitats of the Conterminous United States: U.S. Fish and Wildlife Service, Washington, D.C. USA.
The source data was checked using standard review procedures. Attributes were checked by using visual inspection as well as automated verification routines. Quality of the attribute information varies with age and mapping protocols used when individual maps were prepared
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 all of the conterminous 48 states and the District of Columbia. 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.
Polygon and chain-node topology are present. Every polygon has a label.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- 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
703-358-2161 (voice)
Downloadable Data
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.
| Data format: | ESRI Shapefile or Personal Geodatabase |
|---|---|
| Media you can order: |
CD-ROM or DVD
(format tar)
|
There is no charge for the online option. Requests for large amounts of data are handled on a cost reimbursable basis.
To order files on CD-ROM, please see
703-358-2161 (voice)
608-358-1869 (FAX)
john_cooper@fws.gov