Cropland Irrigation Type, 1987
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.
Source: National Resources Inventory, 1997
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.
Aggregate Layer: State
Other Layers Displayed:
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]
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.
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]
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 ID: 5943
Production Date: 2/8/01
Product Type: Map
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