Abstract: | ABSTRACT: This paper analyzes the sensitivity of drawdown to four hydraulic parameters in unconfined aquifers: horizontal and vertical hydraulic conductivity Kr and Kz, storage coefficient S, and specific yield Sy. Sensitivity coefficients indicate that the sensitivity vanes with time for each aquifer parameter, and Kr, Kz, S, and Sy are identifiable from recovery test data. An inverse method was used to calculate the four parameters from residual drawdowns. Results of application examples demonstrate that residual data provide valid information in the determination of unconfined aquifer hydraulic parameters. |