Law of Sediment Production and Characteristics of Eroded Sediment on Slope Based on Simulated Rainfall

The paper studied law of sediment production,the correlation between the law and runoff,and analyzed the particle characteristics of eroded sediment and original soil through indoor simulated rainfall tests. The outcomes show that a) the runoff time is effected by both rainfall intensity and slope,the greater the rainfall intensity and slope is,the shorter the runoff time will be. The influence of slope to the runoff time will be more obvious along with the increase of rainfall intensity; b) under the different actions of rainfall intensity,the sediment yield( in 4min) shows the trend of increase first and then decrease along with the increase of rainfall duration. The greater the rainfall intensity is,the greater the peak value will be; c) the accumulated sediment yield and accumulated runoff show remarkable power function relationship. It can be expressed by y = AxB,the correlation coefficient R2≥0. 986,reaching a significant level. The coefficient A decreases along with the increase of rainfall intensity and slope and the coefficient B has no significant changes with the effects of rainfall intensity and slope and; d)the particle size distribution of eroded sediment is different under the different rainfall intensity. Comparing with the original soil on the slope,the degree of difference can be shown as 1. 2mm /min 0. 8mm / min 0. 5mm /min. Along with the decrease of rainfall intensity,the relative content of 0. 01mm grain in the eroded sediment is slightly increased and the content of 0. 01mm decreased. This degree of changes is more obvious with the smaller rainfall intensity.