ABSTRACT
Values of the function W(ts. CJ, ~)can be computed with the computer program TYPE13; average drawdown can be computed with the computer program DRA W13 (Appendix B).
a =an empirical coefficient, T-1 r = radial distance from the pumping well, L D = (T/(aSy)]ll2, L
The values of a and D are determined by application of the match-point method (see Section 18.4.1). There have been many attempts to correlate a. with physical aquifer properties. If estimates of these properties are available, estimates of a can be obtained by application of the methods listed below:
Gambolati 0976). Neuman C1979)
(18.16)
a= s~ [3.063-0.567 log (t:•] (18.17) Streltsova (1972)
(18.18)
Prickett ( 1965)
Figure 18.2 Relationship between 1/a and aquifer grain size (from Prickett, 1965).
