or determined with the two boundary conditions as r ® œ, $ = and r — rw, Qo = — 2mHqr. The solution of this equation is then

When r approaches 4A, Ko (4) approaches zero which means that at r > 4A, drawdown is practically negligible. Note that when r/A << 1, Ko(r/A) « -ln(r/1.123A), 0 becomes

This equation is similar to the governing equation for a confined aquifer, Equation 9.3(13), with the equivalent radius Req equal to 1.123A. Therefore, the equation can be rewritten as

Equation 9.3(20) indicates that the drawdown near the well sw can be expressed as sw = -o -

ln r

0 0

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