摘要
以降雨强度和植被覆盖度为两个主要变量,采用人工模拟降雨的试验方式,应用线性和非线性相结合的计算方法,分析研究了降雨强度和植被覆盖度这2个直接因素以及径流量和含沙量2个间接因素在坡地水力侵蚀产沙过程中的复合影响及影响权重,结论如下:在单一要素的拟合分析中,雨强和径流量的相关性最大,植被覆盖度与含沙量的关系最明显。由此推得,雨强对径流量的影响显著,植被覆盖度对产沙量的影响大于雨强;复合相关性拟合显示,产沙量与径流量和含沙量的关系显著,含沙量对产沙量的影响大于径流量的影响,雨强对产沙量的影响大于植被覆盖度;4个分析因素中,对坡地侵蚀产沙影响权重最大的是径流量,2个直接因素中以雨强的影响权重最大。由此提出,在坡地侵蚀产沙的控制实践中,应在坡面水利工程控制坡面径流的基础上,发挥植被覆盖度的作用。
In order to research the effect strength of rainfall intensity and vegetation coverage on slope erosion and sediment yield, the artificial rainfall simulation experiment method is conducted, taking the rainfall intensity and vegetation coverage as two main variables. By the application calculation method of linear and nonlinear combina- tion mathematics, the experiment data are analyzed. The relationships among the amounts of sediment, the rainfall intensity, the vegetation coverage, the slope surface runoff and the runoff sediment concentration are calculated. The influence strengths of rainfall intensity and vegetation coverage on slope erosion and sediment yield are dis- cussed with the principle of entropy weight method. Some conclusions are obtained as follows： Among the single factor analysis, the correlation of the rainfall intensity and the runoff is the most obvious, and the relationship be- tween the vegetation coverage and the sediment concentration is the most significant. Thus, it is infered that the rainfall intensity has significant effect on runoff, the vegetation coverage influence on sediment yield is greater than the rainfall intensity; By SPASS software, compound correlation calculation showed that the relationship among sed-iment yield and runoff and sediment concentration is the most significant, and the influence of the sediment concen- tration on sediment yield is greater than the influence of surface runoff. The effect of rainfall intensity on sediment yield is greater than the influence of vegetation coverage ; In the processes of analysis by entropy weight method, the ordination of the effect strength is the surface runoff 〉 the sediment concentration 〉 the rainfall intensity 〉 the veg- etation coverage among four factors, and is the surface runoff 〉 the rainfall intensity 〉 the vegetation coverage a- mong three factors, and is the rainfall intensity 〉 the vegetation coverage between two factors. This results instruct- ed that largest impact on the slope erosion and sediment yield weight is runoff in two indirect factors and the influ- ence weight of rainfall intensity in the largest in two direct factors. Thus, in practice, the control of slope erosion and sediment yield should play the important role of vegetation coverage on the basis of slope control of water con- servancy projects for controlling overland flow.
出处
《自然灾害学报》
CSCD
北大核心
2017年第5期206-212,共7页
Journal of Natural Disasters
基金
国家自然科学基金(41471221)~~
关键词
侵蚀产沙
复相关分析
熵权法
模拟降雨试验
erosion and sediment
analysis of multiple correlation
entropy weight
artificial simulated rainfall
