坡面泥石流发生的坡度阀值研究  

Critical Gradient and Debris Flow on Mountain Slope

作　　者：曾凡伟[1] 徐刚[1] 李青[1] 

机构地区：[1]西南师范大学资源环境科学学院,重庆400715

出　　处：《地理科学》2005年第2期244-247,共4页Scientia Geographica Sinica

基　　金：西南师范大学自然地理学博士点开放基金资助项目(411408)。

摘　　要：对重庆市北碚区的21个坡面泥石流的实地调查表明,坡度对坡面泥石流发生具有重要的控制性作用。在对坡面泥石流流域大量原始坡度进行统计分析后发现,各坡面泥石流的坡度服从正态分布规律。根据这一分布规律,将本区坡面泥石流发生的坡度阀值确定为三类。文章从定量的角度阐述了坡度阀值与坡面泥石流发生的关系,为生态脆弱区的划分、工程建设、防灾减灾和政府决策提供服务。The investigations on 21 debris flows on mountain slope in Beibei District, Chongqing makes clearly that gradients are very important to debris flow on mountain slope. After counting and analyzing a great deal of the drainage area of debris flow on mountain slope, we find that the distribution of gradients is the normal distribution. According to the distributive laws of the average gradients of the drainages areas of debris flow on mountain slope, we make sure that the critical gradients can be classified into three kinds. The average of the first kind of the critical gradients is 32.4 degrees. The debris flows belonging to the first kind of the critical gradients are apart from residential areas and human being' activities are feeble, and at the same time, their vegetation rates are higher. The average of the second kind of the critical gradients is 27. 3 degrees. The debris flows belonging to the second kind of the critical gradients are located in woodlands and farmlands, and human being' activities are acute and the vegetation rates are lower . The average of the third kind of the critical gradients is 36. 8 degrees. The debris flows belonging to the third kind of the critical gradients are in the Guanyin gorge. They are controlled by the terrain condition. We have quantitatively explained the relationship between the crucial gradients and the debris flow on mountain slopes. It can afford services to the dividing ecological frailty sections, engineering construction, preventing and decreasing disasters, and the government decision-making.

关 键 词：坡度 坡度阀值 坡面泥石流 正态分布 防灾减灾 

分 类 号：P642.23[天文地球—工程地质学]