Development and evaluation of a numerical model for steady state interface and/or free surface groundwater flow

SummaryA 3D numerical procedure is developed to solve free surface and/or freshwater–saltwater interface groundwater flow problems under steady state conditions, using the Galerkin finite element technique and the Picard linearization method to solve nonlinear systems. The presented approach is an improvement of the Larabi and De Smedt (1997) scheme, and is showed to be robust, more efficient, more stable and more accurate than the latter. Benchmark tests involving different features are presented and discussed to validate the present approach.

► A 3D numerical model for free boundaries groundwater flow problems. ► We study freshwater–saltwater interface and free surface groundwater flows. ► A new consistent formula to approximate the conductance matrix entries is proposed. ► Numerical results including benchmark tests are presented and discussed. ► The approach is showed to be robust, efficient, stable and accurate.