| 摘要: |
| 【目的】研究砒砂岩地区坡面径流的侵蚀规律，为该地区坡面水蚀预报模型的建立提供理论依据。【方法】在内蒙古鄂尔多斯市准格尔旗的西召沟内，选取典型的砒砂岩沟坡，采用野外实地放水冲刷试验，对不同冲刷流量（100，150，200，250，300 L/h）和坡度（5°，15°，25°，35°）下砒砂岩坡面径流的水动力学特性进行研究。【结果】在试验的冲刷流量和坡度范围内，砒砂岩地区坡面径流流速均随冲刷流量和坡度的增加而增大，它们之间呈幂函数关系。坡面径流雷诺数（Re）为58.55～442.85，且Re随冲刷时间的延长有增大的趋势。坡面径流弗罗德数（Fr）为0.738～2.281，且Fr随着冲刷流量和坡度的增加而增大。当冲刷流量和坡度较小时，径流流态为层流和缓流；当流量和坡度较大时，径流流态为层流和急流。坡面径流Darcy-Weisbach阻力系数（f）与冲刷流量和产沙量呈反比关系。【结论】相对于其他地区，砒砂岩地区坡面径流水动力学特性有其独特的特征，研究结果可以进一步揭示该地区坡面侵蚀产流产沙机理及侵蚀动力学机制。 |
| 关键词: 砒砂岩地区 坡面侵蚀 水动力学 冲刷试验 |
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| 基金项目:中国科学院知识创新工程重要方向项目(KZCX2-YW-441)；国家科技支撑计划项目(2006BAD09B06)；国家“973”计划项目(2007CB106803) |
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| Study on hydraulic characteristics of slope runoff in Pisha sandstone region |
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| Abstract: |
| 【Objective】The paper studied the erosion rule of slope runoff and provided theoretical basis for water erosion forecast model in Pisha sandstone region.【Method】We conducted the field runoff scouring experiment to study the hydrodynamic characteristics of slope runoff under the different scouring flow discharges (100,150,200,250,300 L/h) and slope gradients(5°,15°,25°,35°).Typical slope of Pisha sandstone in Xizhao gully,Jungar Banner,Erdos,Inner Mongolia was selected as experiment site.【Result】The flow velocity of slope runoff increased with the increase of scouring flow discharges and slope gradients under the flow discharges and slope gradients of this experiment in Pisha sandstone region and there was power function relationship among runoff velocity,scouring flow discharges and slope gradients.The Reynolds number(Re) of the slope runoff varied between 58.55 and 442.85 and Re had the tendency to increase with scouring time.The Froude number(Fr) of slope flow runoff varied between 0.738 and 2.281 and Fr increased with the increase of scouring flow discharges and slope gradients.The flow regimes were laminar flow and subcritical flow when flow discharges and slope gradients were smaller.The flow regimes were laminar flow and supercritical flow when flow discharges and slope gradients were bigger.There was inverse relationship among Darcy-Weisbach drag coefficient(f),scouring flow discharges and sediment yield.【Conclusion】The hydraulic characteristics of slope runoff in Pisha sandstone region are uniquely relative to other regions.The results can further reveal the mechanism of runoff and sediment yield of slope erosion and erosion dynamic mechanism in Pisha sandstone region. |
| Key words: Pisha sandstone region slope erosion hydrodynamics scouring experiment |
