Linear system models for regional aquifer evaluation studies

Abstract

A generalized linear system model is formulated to analyze several types of groundwater flow problems. An iterative procedure is developed to predict aquifer response due to pumping demand by considering the analytical relationships governing the groundwater flow. Historical pumping rates, groundwater levels, stream stages, and estimated storage coefficients are used as inputs to the model. The model outputs are the aquifer transmissivities and the predicted groundwater levels. The sensitivity of the model to variations in the estimated storage coefficients is investigated. The technique is illustrated by considering a realistic but hypothetical regional aquifer system, and the results are demonstrated to be satisfactory. The technique is insensitive even to large errors in the estimated storage coefficients. The number of simultaneous equations to be solved and hence the computational time required are much smaller than those encountered in the conventional numerical models of aquifer systems. Aquifer transmissivity and storage coefficient values are computed as a part of this procedure. Therefore expensive pumping tests that are usually required to estimate these aquifer parameters are not necessary in this technique.