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Acres of Wetlands, 2002

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Description

This map shows the total acres of wetlands on non-Federal land for each Crop Production Region in millions of acres. Nationwide there were 110.6 million acres of wetlands in 2002. Wetlands includes palustrine and non-deepwater estuarine wetlands as defined by the Cowardin system. Deepwater habitats are not included. Wetlands on Federal land are not included.

Cautions for this Product:
The 2002 NRI report gives margins of errors for these wetlands estimates. See also definitions below. No data are available for Alaska, Hawaii, Puerto Rico, the Pacific Basin, or on Federal land.


Sources

Source: National Resources Inventory, 2002
Distributor: USDA-NRCS-RIAD
Reliability:
NRI sample data are generally reliable at the 95% confidence interval for state and certain broad substate area analyses. Generally, analyses that aggregate data points by smaller geographic areas and/or more specific criteria result in fewer data points for each aggregation and therefore less reliable estimates. NRI maps reflect national patterns rather than site- specific information.

Layers

Aggregate Layer: Crop Production Regions
Other Layers Displayed: State

Definitions

Crop Production Regions (CPR):
Also called Farm Production Regions. Developed by USDA, Economic Research Service. These regions are based on share of all farms, average acres operated and value of sales, and crop/livestock share of farm sales.

Cowardin system:
A classification system of wetlands and deep water habitats of the United States, officially adopted by the U.S. Fish and Wildlife Service (FWS) used to develop wetland data bases. The system was developed by Lewis M. Cowardin of the U.S. Fish and Wildlife Service and others. The five major systems are recognized in the NRI: Estuarine, Lacustrine, Marine, Palustrine, and Riverine. [USFWS]

Estuarine system:
Deepwater tidal habitats and adjacent tidal wetlands that are semi enclosed by land but have open, partly obstructed, or sporadic access to the open ocean, and in which ocean water is at least occasionally diluted by freshwater runoff from the land. [USFWS]

Federal land:
A land ownership class designating land that is owned by the Federal Government. It does not include, for example, trust lands administered by the Bureau of Indian Affairs nor Tennessee Valley Authority (TVA) land. No data are collected for any year that land is in this ownership. [NRI-97]

Palustrine system:
All non-tidal wetlands dominated by trees, shrubs, persistent emergents, emergent mosses, or lichens, and all such wetlands that occur in tidal areas where salinity due to ocean derived salts is below 0.5 percent [USFWS]

Wetland:
Areas that have a predominance of hydric soils and that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and under normal circumstances do support, a prevalence of hydrophytic vegetation typically adapted for life in saturated soil conditions. [NFSAM]

Wetland System:
Complex of wetland habitats that share the influence of similar hydrologic, geomorphologic, chemical, or biological factors. [USFWS]

Product Information

Product ID: 8004
Production Date: 3/17/2004
Product Type: Map

For additional information contact the Resources Inventory and Assessment Division. Please include the Product ID you are inquiring about. nri@wdc.usda.gov or 1400 Independence Avenue SW - P.O. Box 2890 - Washington D.C. 20013. If you use our analysis products, please be aware of our disclaimer.