Diagnostic curves for identifying leaky aquifer parameters with or without aquitard storage

Two sets of unimodal diagnostic curves, one set assumes no aquitard storage and the other set assumes aquitard storage, are developed for identifying the parameter of leaky aquifers from early drawdowns, which yields accurate estimates of the parameters and lessens the subjectivity due to personal errors. The proposed diagnostic curve method is simple, easy to apply, and is based on matching of the diagnostically plotted observed drawdowns to an appropriate diagnostic curve. The new method is simple, easy to apply, does not require either the initial guess for the parameter values or repetitive evaluation of the leaky aquifer well function, and outperforms the conventional curve-matching, optimization, extended Kalman filter, and artificial neural network methods. The proposed set of diagnostic curves has a good diagnostic property and is able to easily identify nonideal conditions. The new method suggests a shorter duration pumping test, which would save time, money, and water. It is hoped that the proposed method would be useful to the field engineers and practitioners. DOI: 10.1061/(ASCE)IR.1943-4774.0000116 CE Database subject headings: Groundwater management; Aquifers; Drawdowns; Pumps; Parameters; Estimation; Leakage. Author keywords: Groundwater; Aquifers; Aquitard; Drawdowns; Pumping test; Aquifer parameters; Simple method; Parameter estimation.