中文摘要：

细沟侵蚀是黄土高原坡面极其重要的侵蚀过程之一,汇沙对细沟侵蚀强弱具有重要影响,阐明汇沙对细沟侵蚀的影响与贡献,可以揭示坡面细沟侵蚀过程机理,并为治理坡面水土流失提供科学依据。采用定流量人工放水的组合小区模拟降雨的方法,对不同降雨强度与不同坡度下黄土坡面汇沙对细沟侵蚀的影响及贡献进行了研究,结果表明：细沟上方汇沙、细沟间汇沙、细沟径流剪切力对细沟侵蚀的影响,在不同降雨强度、不同坡度、不同降雨强度及坡度下皆可用三元对数方程描述;细沟上方汇沙、细沟间汇沙、细沟径流剪切力,以及细沟上方汇沙与细沟间汇沙及细沟径流剪切力三者的交互作用对细沟侵蚀的贡献率,在不同降雨强度下分别为13.18%、4.98%、61.2%及8.26%,在不同坡度下分别为4.73%、1.19%、73.65%及5.4%,在不同降雨强度及坡度下分别为10.84%、0.44%、65.22%及6.97%。

英文摘要：

Rill erosion is one of the most important erosion processes on the Loess Plateau. Influx of sediment onto rill has very important effects on rill erosion intensities. Clarifying the impacts and contributions of influx of sedi- ment onto rill to rill erosion can reveal the processes and mechanism of rill erosion, and provide a important scien- tific basis for controlling soil and water loss on hillslope. With multi-plot-based experiments of simulated rainfall and the addition of a steady in-flow at the top of the multi-plot system, the impacts of influx of sediment onto rill on rill erosion and its contribution on loess hillslope are studied under five different rainfall intensities and five different slopes. The main findings are as follows ： impacts of influx of sediment onto rill from rill top, influx of sediment onto rill from interrill, and rill runoff shear stress on rill erosion under different rainfall intensities with same slope, dif- ferent slopes with same rainfall intensity, and different rainfall intensities and slopes can be described by a ternary logarithmic equation. The contributions of influx of sediment onto rill from rill top, influx of sediment onto rill from interrill, rill runoff shear stress, and the interaction of the three terms to rill erosion are 13. 18% , 4.98% , 61.2%, and 8.26% under different rainfall intensities, 4.73%, 1.19%, 73.65%, and 5.4% under the differ- ent slopes, 10.84%, 0.44%, 65.22%, and 6.97% under different rainfall intensities and slopes respectively.