Irrigation Efficiency-Efficiency in Irrigation

Irrigation efficiency

Irrigation Efficiency is the ratio of the water Output to the water Input –usually expressed as percentage.They depends upon the water requirement of crops.The main source of irrigation water is from precipitation.

Input – Output =Losses 

If losses are more, output is less and therefore, efficiency is less 

Efficiency inversely proportional to losses

Water is lost in irrigation during various processes

 

Different kinds of irrigation efficiencies are

1.Efficiency of water conveyance

η? = ????? ????????? ???? ?ℎ? ?????? ???? ?ℎ? ?????? ????? ?? ?ℎ????? /????? ?????? ???? ?ℎ? ?ℎ????? ?? ?ℎ? ???????? ?????
◦ It takes conveyance or transit losses into account ◦ = ??/ ??
◦ ?? – water delivered to the farm or irrigation plot ◦ ??- water supplied or diverted

2. Efficiency of water- application

η? = ???????? ?? ????? ?????? ???? ?ℎ? ???? ???? ?? ?ℎ? ?????/ ???????? ?? ????? ???????? ????????? ???? ?ℎ? ?????
 Farm efficiency

It takes into account the water lost in the farm ◦ = ??/ ??
?? – water delivered to the farm or irrigation plot 

??-water stored in the root zone during the irrigation

?? – ?? + Rf+ Df 

Rf – Surface run off Rf from the farm

Df –deep percolation Df below the farm root-zone soil

3. Efficiency of water –storage

η? =????? ?????? ?? ?ℎ? ???? ???? ?????? ??????????/????? ?????? ?? ?ℎ? ???? ???? ????? ?? ?????????? (?.?.????? ???????? −???????? ???????? ???????)
η? =?? /??
?? – water needed in the root zone prior to irrigation =(Field capacity – Available moisture) 

??-water stored in the root zone during the irrigation

4.Efficiency of water use

η? = ????? ???????????? ????,????????? ????ℎ??? ????? /???????? ?? ????? ?????????

η? = ?? /??
?? – water used beneficially

??-water delivered

5. Uniformity coefficient or Water distribution efficiency

η? = 1− d/D

D = mean depth of water stored during irrigation d = Avg of the absolute values of deviation from the mean

η? ?????????? the extent to which the water has penetrated to a uniform depth, throughout the field 

Water has penetrated uniformly throughout the field, the deviation from the mean depth is zero and water distribution efficiency is 1.0

6. Consumptive use Efficiency η??

η??= ???/ ??×100

??? – normal consumptive use of water 

??- net amount of water depleted from root zone of soil