黄土坡面不同微坡位上糙度对降雨侵蚀的响应

EFFECT OF SOIL SURFACE ROUGHNESS ON RAINFALL EROSION AS AFFECTED BY SLOPE POSITION ON LOESS SLOPE

通过人工模拟降雨试验,结合高精度三维激光扫描技术研究了黄土坡面不同微坡位上糙度对降雨侵蚀的响应特征。结果表明,在同一条件下,坡顶、坡面和洼地上高程统计特征具有明显的差异;在降雨过程中,由于糙度所处的位置不同,对降雨侵蚀的响应特征也不同;地表糙度与微坡度之间存在显著的线性关系。因此,地表糙度对降雨侵蚀的响应规律具有一定的空间差异性。

Surface roughness of farmland, as a result of the joint effects of land management and soil erosion, has a critical impact on the processes of surface runoff and soil erosion. Through simulated rainfall experiments, investigation was made of effect of soil surface roughness on rainfall erosion as affected by slope position on a loess slope, using high- precision 3-D laser scanning techniques. Results show that of the same slope, the top, side and foot was significantly dif- ferent in statistical characteristics of elevation and the effect of soil surface roughness on rainfall erosion was significantly affected by slope position. Soil surface roughness was found to be in significant linear relationship to gradients of micro- slopes. It is, therefore, concluded that the effect of surface roughness on rainfall erosion varies spatially.