Cropland Irrigation Type, 1987
Description
This pie map contains a pie chart for each state
and the nation. The pie slices reflect acres of
irrigated Cropland using various types of
irrigation delivery systems in 1987. The
irrigation types are categorized by 1) Gravity
(orange), 2) Pressure (green), and 3) a
combination of Gravity and Pressure (brown).
The size of the pies is proportional to the
amount of irrigated Cropland.
Cautions for this Product:
The national pie is not proportional to the
state pies. Irrigation on land uses other than
cropland is not included.
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:
State
Other Layers Displayed:
Definitions
Gravity and pressure irrigated:
Farm delivery and field distribution of
irrigation water is a combination of gravity and
pressure facilities. For example, a valve is
used to reduce pressurized water delivered to a
farm or field for subsequent distribution by a
gravity surface irrigation system. [NRI-97]
Gravity irrigated:
Water is delivered to the farm and/or field by
canals or pipelines open to the atmosphere; and,
water is distributed by the force of gravity
down the field by: [NRI-97] 1. A surface
irrigation system (border, basin, furrow,
corrugation, wild flooding, etc.) or, 2. Sub-
surface irrigation pipelines or ditches.
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]
Pressure irrigated:
Water is delivered to the farm and/or field in
pump or elevation induced pressure pipelines;
and water is distributed across the field by:
[NRI-97] 1. Sprinkle irrigation (center pivot,
linear move, traveling gun, side roll, hand
move, big gun, or fixed set sprinklers), or, 2.
Micro irrigation (drip emitters, continuous tube
bubblers, micro spray or micro sprinklers).
Product Information
Product ID:
5943
Production Date:
2/8/01
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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