模拟降雨条件下覆沙坡面产流产沙过程研究

Runoff and sediment yield process on sand covered slope under simulated rainfall

【目的】分析不同覆沙条件下坡面降雨的产流产沙过程,为揭示黄土高原水蚀风蚀交错区风水复合侵蚀机制奠定基础。【方法】采用3个雨强（0.5,1.0,1.5mm/min）和3种覆沙方式（全坡、半坡、无覆沙）在室内进行模拟降雨试验,分析不同雨强和覆沙条件下坡面的产流产沙特征。【结果】坡面覆沙与无沙坡面（裸坡）相比延长了降雨初始产流时间1~30min;坡面覆沙后使得坡面的产流产沙过程复杂化,出现多峰多谷现象;坡面的累计径流量和累计产沙量均与降雨历时呈显著线性相关,相关系数在0.9以上;累计径流量与累计产沙量之间呈函数相关性,相关系数在0.90以上。【结论】坡面覆沙在一定程度上加剧了侵蚀的发生。

【Objective】The runoff and sediment processes on sand covered slop were studied to provide basis for revealing aeolion-fluvial interaction in wind and water erosion crisscross region.【Method】Rainfall was simulated indoor with 3rain intensities（0.5,1.0and 1.5 mm/min）and 3topdressing ways（sand slope,half of sand slope and bare slope）to analyze the runoff and sediment characteristics.【Result】Compared to bare slop,sand slope delayed the initial runoff by 1-30 min.The sand covered slope made the process of runoff and sediment more complex and the phenomenon of multimodal multi-valley appeared.The cumulative runoff and sediment yield were significantly linearly related to rainfall duration with correlation coefficient of above 0.9.The cumulative runoff and cumulative sediment yield also related with correlation coefficient of above 0.90.【Conclusion】The sieved sand slope aggravate erosion occurs in a certain extent.