Question

Over a basin of area $333k{m}^2,$ there was a storm for 6h with a uniform intensity of 2 cm/h. The observed runoff was $20\times {10}^6{m}^3$.The observed rate of infiltration for the basin was

• A. 5 mm/h
• B. 10 mm/h
• C. 20 mm/h
• D. 40 mm/h

Answer 1

The correct option is B 10 mm/h

$A=333k{m}^2$
Storm duration is 6 hr and intensity 2 cm/hr
$\text{Let rate of infiltration be}xmm/hr$

$(2-0.1x)\times {10}^{-2}\times 6\times 333\times {10}^6=20\times {10}^6$
x = 9.99 mm/hr = 10 mm/hr