Unformatted text preview: initial groundwater level (at a depth of 2 m below the ground surface) corresponds to a head of 24 m – 2 m = 22 m. The drawdown just outside the well of 2 m corresponds to a head measured from the base of the aquifer of 22 m – 2 m = 20m, and the drawdown of 0.2 m at a distance of 100 m from the well corresponds to a head of 22 m – 0.2 m = 21.8 m. Substituting in the values h = 21.8 m at r = 100 m; h w = 20 m at r w = 0.1 m; D = 20 m and q = 1.637 × 103 m 3 /sec gives k = [1.637 103 m 3 /sec ln (100/0.1)] [2 20 m (21.8 m – 20 m)] ⇒ k = 5 105 m/s If the drawdown inside the well were increased to 4 m, the aquifer would become unconfined (or strong vertical flow would occur) near the well and the analysis will not strictly be valid. In reality, the error will probably be small, but will increase with increasing drawdown....
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 Fall '11
 StuartChalk
 Analytical Chemistry, Hydrogeology, Vector field, Hydraulic engineering, radius R, hydraulic gradient

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