Question

A watershed 600 ha in area experienced a rainfall of uniform intensity of 2 cm/hr for a duration of 8 hours. If resulting surface runoff is $0.6M{m}^3$ , the average infiltration capacity is

• A. $1.5cm/hr$
• B. $0.75cm/hr$
• C. $1.0cm/hr$
• D. $2.0cm/hr$

Answer 1

The correct option is B $0.75cm/hr$

Total rainfall
$=2cm/hr\times 8hr=16cm$
$\text{Surface runoff}=0.6m{m}^3$

$=\frac{0.6\times {10}^6}{600\times {10}^4}=0.1m$

Loss due to infiltration = 16 - 10 = 6 cm

Average infiltration capacity
$=\frac{6}{8}=0.75cm/hr$