Measurement of rainfall-erosion impacted soil infiltration capability of slope land with run-on-ponding water

Soil infiltration capability(IC) of slope lands is closely related to the rainfall redistributed on the surface. A new method for IC estimated from runoff-ponding water was advanced in this paper. Mathematic models were derived to compute the IC with data for the advance process of runoff and that of ponding depth on soil surface. Laboratory experiments of two cases(rainfall intensity of 60 mm/h, slope gradient of 5 degrees and runoff surface length of 1 m; and rainfall intensity of 30 mm/h, slope gradient of 20 degrees and runoff surface length of 1.5 m) were conducted to collect required data for the demonstration of the experimental and computational procedures to determine the IC curves. The rationale of the measurement and the related algorithms were justified. And comparisons of the cumulated infiltrated waster with rainfall amounts were made to determine the measurement errors to demonstrate the measurement accuracy of the method. The newly suggested method overcomes the shortcomings of the conventional rain simulator and double ring methods. This method has the capability of measuring the full IC curve of slope surface as influenced by rainfall splash, runoff, and soil erosion. This method may supply the researchers in related fields a useful tool.