What is the relation between Consumptive Irrigation Requirement (CIR), Net Irrigation Requirement (NIR), Field Irrigation Requirement (FIR) and Gross Irrigation Requirement (GIR)?

Question

Question

This question was previously asked in

JKSSB JE CE 2015 Official Paper

Answer 1

Explanation

We know,

a) Consumptive Irrigation Requirements (CIR) = Consumptive Use (Cu) – Effective Rainfall (Re)

b) Net Irrigation Requirement (NIR) = CIR + other requirements such as leaching

c) Field Irrigation Requirements (FIR) = NIR + Surface runoff losses + deep percolation losses

Or

\({\rm{FIR}} = \frac{{{\rm{NIR}}}}{{{\rm{Water\;application\;efficiency}}}}\)

d) Gross Irrigation Requirements (GIR) = FIR + Conveyance Losses (Seepage and Evaporation)

Or

\({\rm{GIR}} = \frac{{{\rm{FIR}}}}{{{\rm{Water\;Conveyance\;efficiency}}}}\)

If you look through the above equations we can conclude that

GIR > FIR, FIR > NIR, NIR > CIR

∴ GIR > FIR > NIR > CIR