Definition of Common Words Used in Irrigation

The Cusec

This is an abbreviation used for the term “one cubic foot flow of water per second”. When water is flowing steadily at the rate of one cubic foot per second, the flow is called a cusec.

• 1 cubic foot = 6.5 gallons per second
• 1 cubic foot = 24 *60 *60 (Water requirement for 24 hours).

The Acre Inch

This is a volume measure and is equal to a column of water one inch high standing over an acre.

Gallon

This is another volume measure frequently used for expressing the volume of the water delivered by a water course.

• One gallon of water = 0.16 cubic foot.
• One gallon of water = 10 lbs.

Base Period

This is the period intervening between sowing and last irrigation.

Delta

It is a depth of water in acre inches or a depth of water in acre inches required by a crop during the base period.

Duty

This defines the relationship between the quantity of water used and area irrigated with it. The duty of water is expressed by the number of acres of a crop successfully raised with one cusec of water throughout the period of irrigation of the crop.

Intensity

It is defined as the percentage of the area irrigated by a cusec of water during any season.