rainfall intensity
9.The gullies are formed by the processes of infiltration-interflow-collapses. (2) In the slope with sand-loess,the major factors of water erosion are the rainfall intensity and rainfall amount of annual first rainfall. (3) In the region,the evolution processes of slope gully system results from alternative actions of sand deposition and water erosion.
10.Abstract: In accordance with the problems in the system of well storing rainfall at present,based on the experiments of artificial simulating rainfall,and assistance with the measures of natural rainfall,the relationships among the surface runoff yield,silt concentration,catching runoff efficiency and the material of surface,slope gradient,rainfall intensity are analysed systematically.Then,the best slope gradient and material of surface are chosen,in condition of which surface rainfall yield is the largest and silt concentration is the smallest.This is a beneficial study for the practical use of the rainwater catchment plot in furture.

