Question

An irrigation canal has a culturable command area of 28000 hectares, the intensity of irrigation for Kharif season is 25% and for Rabi season is 60%. If the duty at its head is 700 hectares/cumec for Kharif season and 1680 hectares/cumec for Rabi season, then the design discharge at the head of the canal is

• A. 2 cumec
• B. 20 cumec
• C. 10 cumec
• D. 200 cumec

Answer 1

The correct option is C 10 cumec

Area to be irrigated in Kharif season = $28000\times \frac{25}{100}=7000ha$

Area to be irrigated in Rabi season = $28000\times \frac{60}{100}=16800$

Discharge required in kharif season = $\frac{7000}{700}=10cumec$

Discharge required in Rabi season = $\frac{16800}{1680}=10cumec$

Discharge required in Kharif and rabi season are equal. Thus it will be taken as the design discharge.