Overland flow and infiltration modelling for small plots during unsteady rain: numerical results versus observed values

This paper reports the development and application of a two-dimensional mod el based on an explicit finite difference scheme coupling overland flow and infiltration processes for natural hillslopes represented by topographic e levation and soil hydraulics parameters. This model allows modelling of hor tonian overland flow and infiltration during complex rainfall events. Origi nal procedures have been developed in order to simulate complex rainfall ev ents on natural slopes. The accuracy of the results is tested by comparison with experimental field data on the basis of calibrated soil and surface f riction parameters. Good agreement between the calculated result and the me asured data was found. The scheme proposed was found to be appropriate. The results of tests presented illustrate the effect of microtopography on the distribution of the flow depths, the magnitude and direction of flow veloc ities and infiltration depths. (C) 2000 Elsevier Science B.V. All rights re served.