TOPOGRAPHIC ZONATION OF INFILTRATION IN THE HILLY LOESS REGION, NORTHCHINA

Field infiltration tests using portable rainfall infiltrometers were c onducted in the Wangjiagou experimental basin in the hilly loess regio n of north China. Based on data collected at 27 sites, a topographic z onation of infiltration characteristics was observed. The average stea dy infiltration rate and the average pending time decreased from the h illtop to the hillslope and further decreased to the gully wall. Such a zonation is closely related to the variations of topography, soil an d land use conditions in the study area. A general infiltration model is proposed. Collected field data are used to establish the applicabil ity of the proposed model in the study area.