Abstract
In run-off analysis, it is impotant to consider the physical processes, for example, the infiltration of rainfall into soil and the storage of water in a storage layer etc, because the effective rainfall is governed by these processes. In this study, in order to consider the physical process of run-off in a river basin, an infiltration flow equation was used for the run-off analysis. In computation, the finite difference method is used, but if the mesh size was large, results of calculation would not agree with the theoretical solutions. So the conservation of water was taken into account in the infiltration flow equation. By using this model, the computation result agreed with the observed one very well even in the large mesh scale grids.
