Question

Surface drainage coefficient of a watershed is 1.44 mm/day. What should be the capacity of the surface drain at the outlet of the watershed, if its area is 500 ha ?

• A. $3 \text{ m}^3\text{/min}$
• B. $10 \text{ m}^3\text{/min}$
• C. $5 \text{ m}^3\text{/min}$
• D. $50 \text{ m}^3\text{/min}$

Hint:

To perform this conversion quickly, remember the conversion factor:
$1 \text{ ha-mm/day} = 0.0694 \text{ m}^3\text{/min}$.
Here, $\text{Total ha-mm} = 500 \times 1.44 = 720 \text{ ha-mm/day}$.
$Q = 720 \times 0.0694 \approx 5 \text{ m}^3\text{/min}$.

Answer 1

The Correct Option is C