Drainage Co-efficient
The depth in centimeters of water drained off from a given area in 24 hours is called the drainage co-efficient.
D.C = Total water discharge in 24 hrs (m3)
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Total land area in sq. meters
Ditch capacity (Discharge rate) = Total quantity of water discharged in 24 hrs (cum)
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60 X 60 X 24
Example:
A drainage canal discharge 0.2 cubic meters of water / sec and drains 250 hectares what will be drainage coefficient of this land?
Total water discharge in 24 hrs = 0.2 x 60 X 60 X 24
= 17280 m3
:. DC = 17280 / 250 X 104 = 0.0069m
= 0.69 cm =7 mm