The percentage of irrigation water which is actually stored in the soil and available for use by landscape as compared to the total amount of water provided to the landscape.
Types of Irrigation Efficiency and Calculation Formulas
There are four different kinds of irrigation efficiency:
Type 1 – Water Conveyance Efficiency (ηc)
Water conveyance efficiency refers to the volume of water that is applied to the land and the amount of water that is taken from the source – typically a reservoir. It is calculated using the following equation:
ηc = Wl divided by Wr × 100
In this equation, ηc is water conveyance efficiency, Wl is the volume of water applied to the land, and Wr is the volume of water taken from the reservoir.
Type 2 – Water Application Efficiency (ηa)
Water application Efficiency is a measurement of the amount of water that is stored in plant root systems compared to the volume of water that is applied to the land. The equation is:
ηa = Wz divided by Wl × 100
In this equation represents water application efficiency, Wz represents the amount of water stored in the crop root zone, and Wl represents the amount of water that is applied to land.
Type 3 – Water Use Efficiency (ηu)
Water use efficiency refers to the volume of water that is used versus the amount of water that is applied. The equation is:
ηu = Wu divided by Wl × 100
In this equation, ηu stands for water use efficiency, Wu stands for the amount of water used, and Wl stands for the amount of water applied to the land.
Type 4 – Consumptive use Efficiency (ηcu)
Consumptive use efficiency is determined by comparing the water consumed against the water that is depleted from the crop root zone. The equation is:
ηcu = Cu divided by Wp × 100
In this equation, ηcu represents consumptive use efficiency, Cu represents consumptive use of water, while Wp represents the volume of water depleted from the plant root zone.