RAINFALL INFILTRATION FOR DIFFERENT SOIL SURFACE CONDITIONS.

摘要

A physical model, based on Darcy's law to describe the infiltration behavior under constant rate of simulated rainfall and allowing the development of surface seal is presented.;The results from the model show the effect of surface sealing which controlled the infiltration behavior. Also, the analysis of raindrop impact shows the change in soil property but this concept needs more data from the experiment to approach the realistic in the real world. The effect from settlement shows little importance on infiltration.;The effect of positive head was investigated and taken into account, and it is shown that the infiltration varies considerably due to the rain intensity and characteristics of the surface condition and slope of the land. Three major factors were combined in the model. These are the process of slaking, clogging, and collapsing of soil clods which was applied by an indirect equation, settlement, and compaction from raindrop. Overland flow is included in the model so that the depth of flow can be transferred as a positive head.