REE示踪坡面径流侵蚀演变过程试验研究

Experimental Study on Evolution of Runoff Erosion on the Slopes by REE Tracer Method

通过土槽放水冲刷试验并结合稀土元素（REE）示踪技术,采用沿坡面分层分段布设方式,基于坡面不同部位产沙贡献率的动态变化规律,探讨细沟侵蚀的演变过程。结果表明：在放水冲刷条件下,细沟侵蚀发生的部位集中在坡上段2m,先在距离缓流段末端0~50cm处的表层和中层发育,次之是距缓流段末端50~100cm的表层,之后是距缓流段末端0~100cm的底层,最后在距缓流段末端100~200cm的表层发育。细沟侵蚀在水平方向的发展速度大于在垂向的速度,水平方向的速度是垂向的6倍。

The dynamic changing processes of the rill erosion in slope surface were studied by the means of scouring experiments with the rare-earth element tracer technology placed on different soil depth and section across the soil. The results showed that the mainly parts of the rill erosion was on the top of up slope in two meters. At first, the rill erosion development occurred at the top and middle layer, which was 0-50 cm off the end of slow flow. Then it turned out at the surface that was 50-100 cm off the end of slow flow. Afterwards, the rill erosion appear on the sublayer 0-200 cm off the flow end and surface layer which was 100-200 cm off the flow end in sequence. The speed of rill erosion in the horizontal direction along the slope was 6 times faster than that in the vertical direction.