中文摘要：

为确定放水条件下坡面侵蚀规律，采用3个坡度（15°，18°，21°）和3个流量（3．5，4．5，5．5L·min^-1）交叉组合进行室内冲刷试验，并利用REE示踪法系统分析细沟发生和发展过程？结果表明：坡面上部细沟侵蚀最为剧烈，到试验结束时，坡面上部、中部和下部的沟蚀深度分别在20era、10cm和5era的范围内；上部和中部各层稀土元素示踪区的侵蚀率在试验过程中的变化曲线呈现单峰型或多峰型。流量对各元素示踪区侵蚀率的影响比坡度更为显著，是影响细沟侵蚀量的主要因素。水流流量不变时，在试验初始3min内，坡度对坡面下部的侵蚀影响相对较大。

英文摘要：

To confirm the soil erosion process of the slope scouring, the runoff scouring experiment was applied with three slope gradients （15°,18°and 21°） and three discharges（3.5, 45 and 5.5L·min^-1）by cross and build-up way, and with REE tracer method the occurrence and development processes of interrill was analysed systematically. The results showed that the rill erosion depth of the upper, middle and lower of slope was in the range of 20cm, 10cm and 5cm respectively. The erosion ratio lines of differ- ent REE tracing areas of upper and middle of slope showed single or multiple peaks. The erosion ratios of different REE tracing areas were affected by discharge more significantly than slope gradient, so discharge was the main factor that affected rill erosion yield. During the initial three minutes of the experiment ,the angle of slop had more significantly impact on the erosion of lower part of slop while the current was constant.