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J. H. KLEiNFELDER &ASSOCIATES <br /> Hvorslev (195I) lists several values of shape .factor for different shapes <br /> Of piezometer intakes. These values can also be found in Cedergren <br /> (1967), For thi si':uation where 1/r)8 where: <br /> } <br /> 1 = screen or intake length <br /> r <br /> and the screen or open hole completely P y penetrates an artesian aquifer, <br /> then the shape factor is: <br /> F = 2 <br /> ln(1/r) <br /> t <br /> Substituting this in Equation 1 gives an expression for hydraulic <br /> conductivity as: <br /> r <br /> r2 (ln(l/r)) <br /> 2(1Tb) f <br /> Storativity cannot be found by this method. <br /> 6.2.2 THE COOPER, BREDEHOEFT AND PAPADOPULOS METHOD � <br /> i <br /> e <br /> The method of Cooper, Bredehoeft and Papadopulos (1967) employs a series 1 <br /> of type curves (Figure 3) in which dimensionless head ratio H(t)/Ho is <br /> plotted on the arithmetic ordinate as a function of a dimensionless <br /> < quantity, Tt/r2c where: f <br /> j Ho = head at full depression <br /> sH(t) head at any time during recovery <br /> i. T <br /> trans <br /> missivity <br /> ' t = time since beginning of recovery <br /> r inside radius of casing <br /> r <br /> _o <br /> Y <br /> .J <br /> 53-87-443 : 15 <br />