Question

The Gross Command Area for a distributary is 8000 hectares 80% of which is culturable irrigable. The intensity of irrigation for Rabi season is 50% and the average duty at the head of the distributary is 2000 hectares/cumec. Determine the discharge required at the head of the distributary.

(a) 1.33 cumec

(b) 1.60 cumec

(c) 1.40 cumec

(d) 1.44 cumec

This question was posed to me in unit test.

This key question is from Canal Irrigation System in section Canal Irrigation System of Irrigation Engineering

Answer 1

The correct answer is (b) 1.60 cumec

To explain I would say: Cultivable Command Area CCA = 8000 x 80/100 = 6400 hectares

The area to be irrigated = CCA x Intensity of irrigation = 6400 x 50/100 = 3200 hectares

The water required at the head of the distributary = 3200/2000 = 1.6 cumec.