Influence of Rainfall on Soil Erosion Process on Slopeland with Purple Soil

In order to make clear the process and variation of surface erosion in purple soil,this paper chose a bare purple soil slopeland in Beibei as experimental site to carry out an experiment of artificial simulation of rainfall. The results showed that (1) Rainfall amount was in a positive linear correlation with runoff amount and sediment amount. The variation of rainfall amount remarkably affected the variations of the total runoff amount and the total soil erosion amount. The rainfall intensity was in a highly significant positive correlation with runoff amount and soil erosion amount,but the correlative degree was lower than that between rainfall amount and runoff and erosion amounts. (2) The correlative degree of soil loss amount and break point intensity was greatly different from that between soil loss amount and average rainfall intensity,which was mainly attributed to the fact that average rainfall intensity had generalized the mechanism and process of the rainfall erosion. (3) The functional relationships that can reflect the variable relation of runoff amount and erosion amount were square relationship and power function relationship,and the significance of the regression equation was highly significant. (4) Positive power function correlation existed between rainfall process of high (middle) intensity and runoff and soil erosion amounts,while the runoff amount and soil erosion amount showed a negative linear correlation with rainfall of low intensity.