FINITE ELEMENT MODELLING OF CONTAMINANT TRANSPORT IN SATURATED AQUIFERS

Abstract A Galerkin finite element method is formulated to predict contaminant transport under saturated conditions. The governing equations which are coupled are nondimensionalized to yield four nondimensional parameters. These parameters are the ratio of the aquifer depth to the longitudinal dispersivity of the medium, the ratio of the transverse to longitudinal dispersivity, the ratio of the transverse to longitudinal hydraulic conductivity, and the gradient of the piezometric head. Two finite element grid sizes, one refined near the contaminant source and the other consisting of uniform triangular elements, are utilized to simulate contaminant transport for realistic ranges of the nondimensional parameters. A parametric study is conducted to determine the effects of these parameters on the transport behavior of the contaminant. Numerical difficulties encountered for some typical combinations of these parameters are also mentioned.