REE示踪坡面侵蚀的演变过程

Using Rear-Earth Element Tracers for Studying Spatial and Temporal Process of Soil Erosion in Sloping Land

通过人工模拟降雨,利用分段和分层结合布设不同的稀土氧化物(Rare-EarthOxide),研究次降雨条件下坡面侵蚀的演变过程。结果表明,随降雨的进行,坡面侵蚀一般存在一个由片蚀—近坡角纹沟发育—细沟发育—坡面侵蚀稳定(至基准面)的动态演化过程,各过程中相应侵蚀形态占据主导地位;沟头的出现是导致各侵蚀段侵蚀活跃的重要因素;连续小雨强降雨条件下,坡面以细沟发育为主,侵蚀过程较初次降雨要平稳得多。

By placing different rare earth oxide in different soil depth and different section across a slope in the field plots, the temporal and spatial process of soil erosion is studied under simulated rainfall situation. The results indicated that there is a dynamic process from sheet erosion, ripple erosion near the plot bottom, headward erosion, and relative stableness of slope(ended on the erosion basis). Relevant erosion types were dominant within corresponding erosion stages. The emergence of rill head is the key factor boosting up the erosion of different section on slope. Under gentle intensity consecutive rainfall, headword erosion is dominant on the plots, and its erosion process is much more stable than erosion process of the first rainfall.