中文摘要：

采用REE-INAA方法,采取沿坡面分层分段的新型试验布设方法,研究次降雨条件下坡面侵蚀泥沙来源立体分布规律。结果表明：坡面侵蚀形态演变过程可划分为面蚀、细沟发育和细沟稳定3个阶段。细沟侵蚀是坡面侵蚀产沙的主要原因,试验中的细沟侵蚀产沙量约为面蚀产沙量的9.9倍。可以利用侵蚀产沙贡献率来表征不同试验区域产沙量对总产沙量贡献作用的大小。处于坡面底部的Eu区和Yb区是面蚀量最大区域,其侵蚀产沙贡献率分别为3.1%和3.3%。处于坡面底部的Nd区和Ce区是细沟侵蚀量最大区域,其侵蚀产沙贡献率分别为42.8%和37.5%。坡面中下部是坡面侵蚀泥沙来源的主要区域。

英文摘要：

By placing rare earth elements on different soil depth and different section across the slope,simulated rainfall was applied to study the spatial distribution of sediment source.The results indicated that： The erosion on slope could be divided into sheet erosion,rill erosion developing phase and rill erosion stabile phase.Rill erosion was the main source of the sediment and may be the 9.9 times of the sheet erosion.Erosion distribute rate could be used to indicate the distribute of the erosion in different section.Erosion distribute rates of the Eu section and Yb section in the surface were 3.1% and 3.3%,and erosion distribute rates of the Nd section and Ce section in the bottom were 42.8% and 37.5%.The middle and bottom of the slope were the main sections of the sediment source.