MODELING CONTAMINANT TRANSPORT IN GROUNDWATER - AN OPTIMIZED FINITE-ELEMENT METHOD

An optimized upwind Taylor-Galerkin finite element method (UTGFEM) has been developed to simulate one-dimensional contaminant transport in g roundwater, The model was employed to predict the transport of contami nants from continuous, pulse, and exponentially decaying sources for a wide range of dispersion coefficients and degradation rate constants. The dispersion coefficients considered were 0.0, 1.0, and 5.0 m(2)/da y. The degradation rate constant was varied between 0.007 and 0.028 (d ay)(-1). The model was found to predict the transport dynamics for all these conditions accurately when the dispersion coefficient was great er than or equal to 0.215 m(2)/day. The model would introduce some num erical dispersion if the held dispersion were smaller than this limiti ng value. The need for numerical dispersion can be reduced significant ly by making the length of the finite elements smaller. (C) 1998 Elsev ier Science Inc. All rights reserved.