Aquifer Parameters Estimation Using Artesian Well Test Data

Abstract

Storage coefficient and transmissivity are important and useful parameters for assessing the groundwater potential of an aquifer. For a suddenly uncapped artesian well the drawdown remains fairly constant, whereas the discharge continuously decreases. In 1952, Jacob and Lohman expressed the discharge of such a well in the form of a well function. Considering the type of curve of the tabulated well function makes it possible to estimate the aquifer parameters. However, the matching technique leaves ample scope for error of judgment. In this note, an algebraic function valid in the full range of the argument has been developed. Using this function, it is possible to estimate the aquifer parameters numerically using error minimization. It is shown that the parameter estimates using the present algebraic approximation lead to a better matching between the computed and observed discharges.