Hydrology Journal

A coupled flow-mass transport inverse problem is formulated using the weighted least squares (WLS) estimation concept. A heuristic computational algorithm, the simulated annealing algorithm, is applied to search for a global or near global solution. The resulting inverse model allows for flow and transport parameter estimation, based on inversion of spatial and temporal distributions of head and concentration measurements. A finite element model (FEM) based on Galerkin's approach is developed for computing the head and concentration distribution in the aquifer domain. The developed numerical model is applied to a confined aquifer with a set of boundary conditions, source and sink terms to compute the system parameters within the chosen nine zones of the aquifer. The results indicate that the model can be applied to identify zoned parameters of transmissibility, longitudinal and transverse dispersivity parameters. The chosen aquifer problem is also solved by Gauss-Newton-Marquardt (GNM) method to estimate the parameters and the results are compared with those obtained using simulated annealing (SA). Largely, the SA results are found better compared to GNM parameter estimates, except, when error free head and concentration data is used, which is not possible in problem of practical interest.