Modified Solutions for Decreasing Discharge Wells

Several modified solutions are proposed for the problem of nonsteady flow to a well of decreasing discharge that completely penetrates an extensive artesian aquifer. The solutions reduce the computations required in using a general solution previously developed. A particular modified solution depends on the magnitude of the discharge and aquifer characteristics. In general, the analytical solutions for nonsteady confined flow to a well available for determination of aquifer characteristics or drawdown assume that the discharge of the well is essentially constant over the period of pumping; and yet, in many cases, some change does take place. This is particularly true during short-term pumping tests. Neither the Theis or Jacob methods nor the proposed solutions for nonsteady flow were very satisfactory when applied to a field test cited as an example.