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Acres of 1982 Rangeland Converted to Developed Land in 1997
Description
This shaded polygon map shows the amount of
rangeland converted to developed land between
1982 and 1997 within each 8-digit hydrologic
unit. The acres converted are presented in four
categories based on the following divisions:
20,000 or more acres, 5,000 to 20,000 acres,
2,000 ro 5,000 acres, and less than 2,000
acres. A total of 3.28 million acres were
converted. Developed land includes urban and
built-up areas and rural transportation land.
Metropolitan Statistical Areas are indicated by
black squares. Areas with 95% or more Federal
area are shaded gray.
Cautions for this Product:
This map does not show the total amount of
rangeland or developed land. Data are not
collected on Federal land. Data are not
available for Alaska or the Pacific Basin. Data
for Puerto Rico and the U.S. Virgin Islands are
shown by 6-digit hydrologic unit.
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:
Rivers, States, Metropolitan Statistical Area (MSA) Lat/Long selec
from GNIS
Definitions
Developed land:
A combination of land cover/use categories,
Urban and built-up areas, and Rural
Transportation Land.
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]
Hydrologic units:
A hierarchical system developed by the U.S.
Geological Survey that divides the United States
and the Caribbean into 21 major regions, 222
subregions, 352 accounting units, and further
subdivided into 2,150 cataloging units that
delineate river basins having drainage areas
usually greater than 700 square miles. [USGS]
Rangeland:
A Land cover/use category on which the climax or
potential plant cover is composed principally of
native grasses, grasslike plants, forbs or
shrubs suitable for grazing and browsing, and
introduced forage species that are managed like
rangeland. This would include areas where
introduced hardy and persistent grasses, such as
crested wheatgrass, are planted and such
practices as deferred grazing, burning,
chaining, and rotational grazing are used, with
little or no chemicals or fertilizer being
applied. Grasslands, savannas,
many wetlands, some deserts, and tundra are
considered to be rangeland. Certain communities
of low forbs and shrubs, such as mesquite,
chaparral, mountain shrub, and pinyon-juniper,
are also included as rangeland.
[NRI-97]
Rural transportation land:
A Land Cover/Use category which consists of all
highways, roads, railroads and associated rights-
of-way outside urban and built-up areas;
including private roads to farmsteads or ranch
headquarters, logging roads, and other private
roads, except field lanes. [NRI-97]
Urban and built-up areas:
A Land Cover/Use category consisting of
residential, industrial, commercial, and
institutional land; construction sites; public
administrative sites; railroad yards;
cemeteries; airports; golf courses; sanitary
landfills; sewage treatment plants; water
control structures and spillways; other land
used for such purposes; small parks (less than
10 acres) within urban and built-up areas; and
highways, railroads, and other transportation
facilities if they are surrounded by urban
areas. Also included are tracts of less than 10
acres that do not meet the above definition but
are completely surrounded by Urban and Built-up
land. Two size categories are recognized in the
NRI: (i) areas 0.25 to 10 acres, and (ii) areas
greater than 10 acres. [NRI-97]
Product Information
Product ID:
5880
Production Date:
3/19/01
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.
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