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A drainage basin has an area of 210 km2. The average depth of rainfall received by it during a monsoon period is computed as 65...

A drainage basin has an area of 210 km2. The average depth of rainfall received by it during a monsoon period is computed as 65 cm, while the runoff measured at its outlet during the same period is estimated to be 5.68 x 107 m3. Compute the depth of runoff. What percentage of rainfall has become runoff? If all this runoff volume is stored and used to irrigate a crop which requires 60 cm of water, how many hectares can be irrigated?

Answers

Jim
Depth of runoff = Volume of runoff/Basin area
=5.68 x 107/210 x 106 = 0.2705 m = 27.05 cm

% of rainfall that became runoff
=(27.05/65) x 100 = 41.62%

Area of crop that can be irrigated
=Volume of runoff/Irrigation depth
=5.68 x 107/0.6 = 9.467 x 107 m2
=94.67 km2 = 9,467 hectares
jim items answered the question on April 9, 2018 at 18:23

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