Question

A catchment consists of 30% area with runoff coefficient 0.40 with the remaining 70% area with runoff coefficient 0.60. The equivalent runoff coefficient will be

• A. 0.48
• B. 0.54
• C. 0.63
• D. 0.76

Answer 1

The correct option is B 0.54

The equivalent runoff coefficient is given by
$K=\frac{K_1{A}_1+K_2{A}_2}{A_1+A_2}$

$=\frac{0.4\times 0.3+0.6\times 0.7}{0.3+0.7}$
= 0.54