A Finite Element-Finite Difference Alternating Direction Algorithm for Three Dimensional Groundwater Transport

Abstract

While technically feasible, three dimensional finite element groundwater transport simulation has not found widepsread application because of the considerable computational burden inherent in the approach. An operator splitting algorithm which treats the horizontal plane using finite elements in the first step and the vertical dimension using finite differences in the second step provides considerable savings in both computer memory requirements and computational effort. The algorithm reduces the problem of an (N × M) array of nodes from one in which NM equations must be solved simultaneously, to one of solving N equations M times in the first step and M equations N times in the second step. Applications to type problems and field situations indicate that the method is robust and accurate.