A Modified Hortonian Overland Flow Model Based on Laboratory Experiments

Overland flow, which is examined here, is an important hydrological response to storms of a catchment. And it is also a main component of hillslope hydrology. Through controlling of rainfall intensities and changing of artificial slope angles, 49 overland flow hydrographs are obtained from rainfall-runoff simulation experiments conducted on a manmade hillside. Based on the measured overland flow processes, the relationship between the average water depth on the hillslope and that at the outlet, which is nearly a quadratic curve, is obtained. The relationship is different from the assumption, in which the average water depth on the hillslope is equal to that at the outlet, proposed by Horton. Finally, a regression equation is also presented, which provides both the theoretical and experimental basis to modify the time delay of peak flow for a distributed rainfall-runoff modeling. Copyright Springer Science + Business Media, Inc. 2006