Modeling Infiltration into a Multi-layered Soil during an Unsteady Rain

Abstract

The Green-Ampt model is generalized to model infiltration into a multi-layered soil during an unsteady rain. One dimensional numerical simulation scheme of the Richards equation is also developed which is suitable to deal with transfers between two kinds of boundary conditions-water flux control and water head control. Modeling results of the generalized Green-Ampt model are compared with a numerical simulation for cases of 2 and 3 layered soil as examples. It is shown that the proposed model matches the Richards equation quite well with computation time less than tenth of the latter, thus promising to play a role in watershed modeling.