雨滴击溅对薄层水流水力摩阻系数的影响

The Effects of Raindrop Splash on the Sheet FlowHydraulic Friction FactorWu Pute

采用模拟降雨的试验方法，在分析计算有无雨滴击溅作用坡面薄层水流水力摩阻系数的基础上，进一步分析了雨滴击溅作用对薄层水流水力摩阻系数的影响。结果表明，雨滴击溅作用可减少薄层水流的水力摩阻系数，从而减少水流摩擦阻力，使水流侵蚀力相对增大；有雨滴击溅作用时其水力摩阻系数平均为无雨滴击溅时的６６．１４％。这说明雨滴的击溅除了本身的分散和破坏土壤结构等侵蚀作用外，还可降低水流的水力摩阻系数，从而增加径流的冲刷力。

By the simulated rainfall experiment, based on the analysed and calculated the sheet flowfriction factors with raindrop splash and without raindrop splash , the effects of ratridrop splash on thesheet flow hydraulic friction factor was studied in this article. The results show, raindrop splash canreduce the friction factors of sheet flow , and reduce the sheet flow friction force, so that it can add thesheet flow erosion force. By our test results, the average reduction value is 66. 14 % , this indicate thatthe raindrop splash not only can destory the soil structure, but also can reduce the friction factors,and add the sheet flow erosion force.