Acres of Irrigated Land Converted to Developed Land, by Farm Production Region, 1982-1997
Description
This bar map shows changes in the acreage of
Developed Land for Farm Production Regions that
was irrigated land in the previous year. Each
region contains 3 bars showing acreage of
developed land in 1987 that was irrigated in
1982; acreage of Developed Land in 1992 that
was irrigated in 87; acreage of developed land
in 1997 that was irrigated in 1992. The length
of each bar is proportional to the number of
acres it represents.
Cautions for this Product:
The national totals are not proportional to the
regional totals.
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:
Farm Production Regions
Other Layers Displayed:
State
Definitions
Cropland:
A Land cover/use category that includes areas
used for the production of adapted crops for
harvest. Two subcategories of cropland are
recognized: cultivated and noncultivated.
Cultivated cropland comprises land in row crops
or close-grown crops and also other cultivated
cropland, for example, hayland or pastureland
that is in a rotation with row or close-grown
crops. Noncultivated cropland includes permanent
hayland and horticultural cropland. [NRI-97]
Developed land:
A combination of land cover/use categories,
Urban and built-up areas, and Rural
Transportation Land.
Irrigated land:
Land that shows evidence of being irrigated
during the year of the inventory or during two
or more years out of the last four years. Water
is supplied to crops by ditches, pipes, or other
conduits. Water spreading is not considered
irrigation; it is recorded as a conservation
practice. [NRI-97]
Pastureland and Native Pasture:
A Land Cover/Use category of land managed
primarily for the production of introduced or
native forage plants for livestock grazing.
Pastureland may consist of a single species in a
pure stand, a grass mixture or a grass-legume
mixture. Management usually consists of
cultural treatments-fertilization, weed control,
reseeding, or renovation and control of
grazing. (For the NRI, includes land that has a
vegetative cover of grasses, legumes, and/or
forbs, regardless of whether or not it is being
grazed by livestock.) [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:
5345
Production Date:
12/13/00
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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