The differential system method for parameter identification; unconfined aquifer case

Abstract

We present the applicability of differential system (DS) method for identification of hydraulic conductivity and effective porosity in a phreatic aquifer. In the original setting, the first step of the DS system is to solve an overdetermined algebraic system in the least squares sense. A natural extension of the method is to pose a least squares problem in an appropriate functional space. We show an improvement of the identification by considering the least square problem in the space of square integrable functions in the time variable for a finite interval.

Development of objective‐oriented groundwater models: 1. Robust parameter identification

“…The direct method is difficult to use in practice because it requires distributed observations of all nodes and the inverse solution is very sensitive to any observation error [ Sun , 1994]. The instability problem associated with the direct method is eased in some recent studies by adding constraints or using nonlinear objective functions [ Knowles et al , 2004; Moreles et al , 2005]. The data insufficiency problem, however, still exists.…”