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浅沟侵蚀是黄土高原重要的侵蚀类型,上方汇水对坡面浅沟侵蚀具有重要的影响。采用野外放水冲刷试验,定量分析26°坡耕地在上方来水量为5、10和15 L/m in时对坡下方浅沟侵蚀产沙及其水动力参数的影响。结果表明:上方来水的汇入使浅沟水流流速明显增大,雷诺数、弗劳德数、水流功率和剪切力分别增大33%～76%、21%～47%、29%～72%和18%～42%,阻力系数减少11%～13%,导致浅沟侵蚀产沙量明显增大;除流速和弗劳德数外,其余水动力参数随放水时间的延长呈递增趋势;上方来水使浅沟侵蚀产沙量相对增量与水流功率和剪切力相对增量均呈幂函数关系。
Slightly groove erosion is an important type of erosion in the Loess Plateau. Above the catchment water has an important impact on slope erosion. A field scouring test was conducted to quantitatively analyze the effects of scald erosion and sediment yield and hydrodynamic parameters at a slope of 26 ° on top of the slope at a slope of 5 ° and 15 L / m in. The results show that the flow rate of shallow gully water obviously increases with the inflow of upper water, and the Reynolds number, Froude number, water flow power and shear force increase by 33% -76%, 21% -47%, 29% 72% and 18% -42%, and the drag coefficient decreased by 11% ~ 13%, resulting in a significant increase in the shallow furrow erosion and sediment yield. Except for the flow rate and the Froude number, the rest of the hydrodynamic parameters showed an increasing trend with the prolongation of the water release time The relative increase of runoff erosion and sediment yield in upper part of water came from power function relationship with the relative increase of flow power and shear force.