Percent Change in Cropland Area, 1992 - 1997
Description
This shaded polygon map shows the percent change
in the amount of cropland (cultivated and non-
cultivated) area from 1992 to 1997 within each 8
digit hydrologic unit, using 1992 as a base
year. The percentages are presented in five
categories based on the following divisions: an
increase of more than 25%, an increase of 5% to
25%, little change (less than 5% change), a
decrease of 5% to 25%, and a decrease of over
25%. There was an average decrease of 1.4% for
the nation. Areas where cropland occupy less
than 5% of the total area in either year are
hatched. Areas with 95% or more Federal area are
shaded gray.
Cautions for this Product:
Areas with small amounts of cropland may have
very high rates of change. This map may not be
used to determine site-specific information.
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 aggregated 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:
States, Rivers
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]
Cultivated Cropland:
Includes land identified as being in row or
close crops, summer fallow, aquaculture in crop
rotation or other cropland not planted --
including cropland in short-term set-aside
programs; or land in horticulture that is double
cropped; or land in hay which had at least one
of the three previous years in row or close
grown crops; or land in pasture which had at
least one of the three previous years in row or
close grown crops.
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]
Non-cultivated cropland:
Includes land in horticulture that is not double-
cropped; or land in hay which had not been in
row or close-grown crops for any of the previous
three years.
Product Information
Product ID:
4975
Production Date:
1/12/01
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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