Simple equations for aquifer parameters from drawdowns in large-diameter wells

Simple equations are proposed for estimating storage coefficient and transmissivity of an aquifer from drawdowns in largediameter wells. The proposed method requires determination of the peak and time to peak of a unimodal curve. Using these values and utilizing the provided set of equations, the aquifer parameters are estimated through an iterative procedure. The proposed method is void of subjectivity involved in the previously proposed curve matching methods. Also, the new method can be used when the conventional curve matching methods cannot be applied to estimate the aquifer parameters. The new method can be used to estimate the aquifer parameters from the drawdown data observed only up to a time so that the peak could be determined. DOI: 10.1061/(ASCE)0733-9437(2007)133:3(279) CE Database subject headings: Water storage: Coefficients: Wells: Aquifers; Ground water; Pumps; Unsteady flow; Estimation.