Question

A certain crop needs 3 cumec of water for irrigating 5100 hectares land up to 10 cm depth. Total 12 watering at an interval of 10 days are needed. Duty and delta (in hectare/cumec and cm respectively) will be:
1. 51000, 1200
2. 15300, 0.12
3. 1700, 120
4. 510, 1.2

Answer 1

Correct Answer - Option 3 : 1700, 120

Concept:

Duty:

It is the area of land that can be irrigated with a unit volume of water supplied across the base period. It is generally expressed in hectare/cumec.

Delta:

It is the depth of water required to a crop over a unit area across the base period for full growth of the crop. It is generally expressed in cm or m.

Calculation:

Given:

Dicharge (Q) = 3 cumec

Area of land (A) = 5100 hectare

Than, duty = 5100/3 = 1700 hectare/cumec

For delta:

Water depth = 10 cm

Number of watering = 12

Then, delta = 12 x 10 = 120 cm