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GATE 2016 CE (CE1) – Question 24

Hydrology · Streamflow measurements, unit hydrographs, hydrograph analysis · 1 mark · Numerical answer

The direct runoff hydrograph shown results from 5 cm of rainfall excess. The catchment area is ______ ha.

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Correct answer: 21.5 to 21.7

Explanation

Runoff volume is the area under the hydrograph. A6-hour triangular base and1m³/s peak give V=(1/2)·6·3600·1=10800m³. With excess rainfall0.05m, area=10800/0.05=216000m². Dividing by10000 gives **21.6ha**.