Effect of Vegetation Buffers of Different Positions on Sediment Source in the Slope

In order to study the effect mechanisms of vegetation on erosion and sediment transport, the artificial rainfall simulator and three-dimensional scanning technology were used to investigate the character of sediment sources in different positions of vegetation buffers. The results show that the main source of sediment yield is in section from the middle to the lower part of the downslope area where there is no vegetation, and the most serious erosion distributes in this area; the main region of sediment source is located in the middle lower part of the downslope and the whole downslope as the grass strip is laid in the lower part of the upslope and the middle lower part of the upslope where the erosion is alleviated; when the grass strip moves to the upper part of upslope, runoff flows longer and sediment yield has more sources, the main source area of erosion moves up simultaneously, which even extends from the lower part of the downslope area to the middle part of the upslope; the main erosion range increases by 2～3 times, and the degree of erosion increases by 24%～45%, the erosion sediment yield reaches the peak within the test range; when the planted grass strip occupies 60% of the upslope length, its regulation range can cover the entire slope, effectively controlling the main erosion range and degree are 33% and 53% lower than those of bare slope, respectively, which better controls the mechanism of erosion and sediment transport, more importantly, transforms the main erosion pattern from rill erosion into sheet erosion; the regulation of vegetation on the processes of erosion and sediment transport is realized in the slope. The information indicated that vegetation in different positions of slope can regulate sediment source in a slope by affecting the erosion patterns.