Abstract
An approach is presented to solve the Philip's equation with time compression approximation (TCA) for simulating infiltration under variable rainfall. This approach brings understanding into physical processes of infiltration and ponding during variable rainfall storms. In particular, we apply it into the Yamanashi Hydrological Model (YHyM) for analyzing the infiltration excess runoff in arid and semi-arid regions. The soil water redistribution is also included to simulate the soil moisture changing during the temporal gaps among storms. The modified YHyM was tested by a case study of Lushi River basin, China. Through comparisons of results from the modified YHyM with results from the unmodified YHyM, the presented TCA based infiltration model is proved to be able to improve the performance of YHyM in peak runoff calculation during variable rainfall multi-storms in arid and semi-arid regions.
