Numerical simulation of three-dimensional unsaturated flow in a heterogeneous porous medium

Abstract

A three-dimensional, numerical simulation of infiltration into a heterogeneous, unsaturated porous medium is presented. The finite-element computer model, MMOC3, for flow in variably saturated media is used for the simulation. The model is constructed using measured lithologic and hydraulic data for an artificial infiltration field experiment which was conducted prior to construction of this model. Measured lithologie and hydraulic data from the field investigation are analyzed and representative data are selected to construct the model. Results for the simulated infiltration behavior are analyzed and compared to the measured infiltration behavior at the field study, over a 21 day period. The results of the model simulation do not satisfactorily reproduce the measured field results. Factors which are probably responsible for this discrepancy are considered, including the adequacy of the measured field data and the effectiveness of the model. Recommendations for future three-dimensional, unsaturated flow modeling are also explored.