Comparison among General Programs for Numerical Analysis of Rainfall Infiltration Processes

Rainfall infiltration processes have many points of attention, such as non-linearity of unsaturated hydraulic properties, boundary conditions and fluid behavior. On the other hand, inexperienced users may analyze without understanding these points because numerical analysis packages are widely used. We examined the influence of differences in handling such as boundary conditions and unsaturated hydraulic properties on analysis results for rainfall infiltration problems on slopes using general programs for the saturated and unsaturated seepage flow. As a result, there is little difference in analysis results such as temporal change of pressure heads when the initial saturation is high. On the other hand, in the initial dry state, the analysis results show some differences in the handling of fluid behavior and unsaturated hydraulic conductivity.