STOCHASTIC ANALYSIS OF CONTAMINANT TRANSPORT THROUGH SOILS

Abstract

Transport of pollutants through porous media has received lot of attention in last few decades. Porous media characteristics may vary spatially and this has lead to the use of a variety of model parameters, particularly, hydrodynamic dispersion coefficient. In this work a one dimensional solute transport is studied by treating hydrodynamic dispersion coefficient as a stochastic variable. As this parameter is also considered varying with longitudinal distances, numerical solutions are developed using MacCormack scheme. The performance of numerical scheme is found to match closely with analytical solutions for a step input. Resulting distributions of concentrations as well as the hydrodynamic dispersion coefficient at different points in the flow domain has been analyzed. It has been observed that there is a wide variation in the nature of probability distribution functions and it is improper to attribute same probability distribution for concentration and hydrodynamic dispersion coefficient. The conditions tested in this study have included a wide variation of longitudinal dispersivity/dispersion coefficient, based on reported values in the literature from lab as well as field studies.