6-Modelling of Pollutant Transport Through Unsaturated

Abstract

The transport of pollutants through the unsaturated zone is governed by Richard's and mass transport equations. Thus, the distribution of pollutant in space and time for given initial and boundary conditions, can be estimated by the solution of the two coupled differential equations. However, the conventional numerical techniques may lead to siginificant errors due to 'numerical dispersion' especially when the convective and the diffusive transports are of the same order of magnitude. A numerical algorithm for the solution by the method of characteristics is described. The resulting model has been tested using reported data.