Concept: We have two sources of water to be used as irrigation water one is groundwater and the other is flowing water. Based on the source of water used as irrigation water, a water irrigation system is mainly divided into two categories:
Lift irrigation – When groundwater lifted up to be used as irrigation water or water supply is at too low a level to run by the gravitation of the land.
Flow irrigation – when flowing water is used as irrigation water.
These are further classified as below –
Flow irrigation:These are also called gravity irrigation. It is the type of irrigation in which water is available at a higher level to enable supply to the land by gravity flow.
It is further divided into two categories
1) Inundation irrigation: It is done canal taking off from a river in flood without any diversion head work. It depends on the periodical rise in the water level of the river and supply is drawn through open cuts in the river bank or creeks which are called heads. Inundation canals usually flow during the summer months and bring in a large quantity of silt beneficial to crops.
e.g. river canal irrigation. 2) Perennial Irrigation: In this system assured supply of water throughout the crop period to irrigation requirement of the crops is made available to the command area through storage of water done at dam or diversion supply made by means of headworks at the off-take point of the canal. Perennial irrigation may be either
direct (e.g reservoir or tank), storage (indirect), or combined.