Water Resources GWU Geog 2136 EXAM 1 pt. 2

What is the difference between stomata controls and interception? (***)

Stomata controls water going though the plant, interception is the water stored on top of the leaves (because of the canopy)

Types of Precipitation

Rain, snow, hail, dew, occult

What are the trends of water usage in the United States (increasing or decreasing)?

Decreasing

What is irrigation water?

Water that is applied by an irrigation system to sustain plant growth in all agricultural and horticultural practices

What percent of total water withdrawals are accredited to irrigation?

64%

What percent of all freshwater withdrawals go to irrigation?

60%

Why did irrigation acreage double between 1950 and 1980?

Creation of dams, wells, irrigation systems…green revolution!

What are the three types of irrigation?

Surface, sprinkler, and micro-irrigation

Surface irrigation

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Sprinkler irrigation

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Micro-irrigation

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Is surface irrigation efficient?

No, around half of the water used never gets to the crops, but it is cheap.