Percent of Non-Federal Area in Water, 1987
Description
This map shows the spatial distribution of the
nation's open surface water in 1987 as a
percentage of non-Federal area within each 8-
digit hydrologic unit. There were 49,893,600
acres of water in 1987. This includes Small
Water and Census Water.
Cautions for this Product:
Use this map only to identify broad spatial
trends.
Sources
Source:
National Resources Inventory, 1997
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:
8 Digit Hydrologic Unit Areas with Federal Land
Other Layers Displayed:
State
Definitions
Census Water:
Includes water bodies at least 40 acres in size
and perennial streams at least 1/8 mile wide.
Also referred to as Large Water. [NRI-97]
Non-Federal land:
Includes all land and water areas where the
ownership is by private, municipal, county or
parish, state, Indian tribal, individual trust,
the Tennessee Valley Authority, or areas under
temporary control of a Federal, state, county or
municipal agency or government for foreclosure
or nonpayment of taxes.
Small water bodies:
Inland bodies of water with a water surface area
of less than 40 acres. This distinction is made
by the U.S. Bureau of the Census. [NRI-97]
Water areas:
A Land cover/use category comprising water
bodies and streams that are permanent open
water. [NRI-97]
Product Information
Product ID:
6022
Production Date:
1/25/01
Product Type:
Map
For additional information
contact the Resources Inventory and Assessment Division.
Please include the Product ID you are inquiring about.
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Washington D.C. 20013. If you use our analysis products,
please be aware of our disclaimer.
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