坡面侵蚀产沙与水力学特征参数关系模拟

发布时间：2018-03-30 03:29

本文选题：侵蚀产沙　切入点：水力学参数　出处：《水土保持学报》2017年05期

【摘要】：坡面侵蚀产沙主要受坡面径流动态过程的影响,表征坡面径流过程特征是水力学特征参数。为了研究坡面侵蚀产沙与主要水力学特征参数的关系,揭示坡面侵蚀产沙的水动力学机理。采用人工模拟降雨的方式,通过不同坡长和雨强的组合试验,基于跨雨强和跨坡长的综合性分析的思路,应用经典水力学计算和统计拟合相结合的方法,对特定坡度(20°)下,5个坡长(1,2,3,4,5m)13个降雨强度的试验监测数据进行了分析。结果表明:(1)在设计雨强(0.65~2.0mm/min)和坡度范围内,坡面径流都属于缓流,雨强0.7mm/min都为层流,呈现紊流的最小雨强为1.01mm/min;(2)坡长对弗汝德数和阻力系数的影响较大,对剪切力、径流深和雷诺数的影响很小,3m坡长是坡面径流过程的波动步长,是模拟试验研究坡面径流水动力学参数的最小设计坡长;(3)流速是坡面侵蚀产沙的主要影响参数,剪切力是判断坡面侵蚀产沙强度的综合性指标之一。这些研究结论为实地大范围通过径流量和流速来预测侵蚀产沙的强度提供了简便快速的判断方法。
[Abstract]:Slope erosion and sediment yield are mainly affected by the dynamic process of slope runoff, which is characterized by hydraulic characteristic parameters, in order to study the relationship between erosion and sediment yield on slope surface and main hydraulic characteristic parameters. The hydrodynamic mechanism of slope erosion and sediment yield is revealed. By means of artificial rainfall simulation and combined experiments of different slope lengths and rainfall intensities, the train of thought of comprehensive analysis of cross rain intensity and cross slope length is presented. Using the method of classical hydraulics calculation and statistical fitting, the experimental monitoring data of 13 rainfall intensities at 5 slope lengths (1 ~ 2 ~ 3 ~ 3 ~ 3 ~ 3 ~ 4 ~ 5 ~ 5 m) under a given slope (20 掳) are analyzed. The results show that: 1) in the range of design rain intensity of 0.65 卤2.0 mm / min) and slope, The slope runoff belongs to the slow flow, the rain intensity 0.7mm/min is laminar flow, the minimum rain intensity of the turbulent flow is 1.01mm / min / min / 2) the slope length has a great influence on the Froude number and the resistance coefficient, and it has great influence on the shear force. The influence of runoff depth and Reynolds number is very small. The slope length of 3 m is the fluctuation step of runoff process on the slope. It is the minimum design of hydrodynamic parameters of runoff in simulation experiment. The flow velocity is the main influence parameter of erosion and sediment yield on slope surface. Shear stress is one of the comprehensive indexes to judge the intensity of erosion and sediment yield on slope surface. These conclusions provide a simple and rapid method for predicting the intensity of erosion and sediment yield through runoff and velocity in a large scale.
【作者单位】：浙江大学城市学院信息与电气工程学院;浙江省农业资源与环境重点研究实验室浙江大学土水资源与环境研究所;
【基金】：国家自然科学基金面上项目(41471221)
【分类号】：S157.1

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