Subtopic: Steady and unsteady flow in confined and unconfined aquifers
Question Statement:
The porosity and compressibility of a 7.8 m thick confined aquifer are 0.25 and 1×10⁻⁸ m² N⁻¹, respectively. The storage coefficient of the aquifer is 6.5×10⁻⁴. To release 650 m³ of water from 1 km² of this aquifer, the average decline in hydraulic head will be ________ m.
Official Answer Key:
1.00 to 1.00
Step-by-Step Solution & Explanation
Definition of storage coefficient: S = V_w/(A × Δh).
Δh = V_w/(S × A) = 650/(6.5×10⁻⁴ × 1×10⁶)
= 650/650 = 1.0 m.
The porosity, thickness and compressibility values are redundant here — they would only be needed if S itself had to be computed.
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