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Hydrology & Irrigation

Yield of an Unconfined Aquifer-Part-2

In an unconfi...

Question

In an unconfined aquifer, when the steady rate of pumping was $90 m^{3} / h r$ , the following observations are made as shown in figure, Transmissivity of the aquifer will be ____ $m^{2} / d a y$ .

A

40

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B

80

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C

130

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D

160

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Solution

The correct option is B 80
$Q = \frac{π K (h_{1}^{2} - h_{2}^{2})}{ln (r_{1} / r_{2})}$

$Q = 90 m^{3} / h$

$= 2160 m^{3} / d a y$

$2160 = \frac{π K (39^{2} - 35^{2})}{ln (\frac{70}{30})}$

$K = 1.968 m / d a y$

$T = K H$

$= 1.968 \times 40 = 78.7 m^{2} / d a y$

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