激发坡面泥石流形成的降水因素探讨--以重庆北碚地区为例

从重庆市北碚区坡面泥石流形成的地质、地貌和气象条件入手,分析了北碚区1962—2003年发生的坡面泥石流数据及降雨资料,认为在该区域,降水是发生坡面泥石流的决定性因素,坡面泥石流的发生与前期降雨量和1 h雨强关系密切,前期降雨对泥石流形成的贡献比较大,1 h雨强主要起到激发作用。通过对泥石流的降雨指数分析,认为在该区当1 h降雨量达到40 mm,降雨指数达到160,综合指数达到650,就可能发生坡面泥石流。

Study of Precipitation Factor Inducing Debris Flow on Slope--A Case Study of Beibei, Chongqing

The effects of precipitation on debris flows on slope in Beibei District,Chongqing City,were investigated after the study of the formation conditions and their relations with the geologic,geographical and climatic conditions.The data for debris flows and precipitation during 1962-2003 were analyzed with a case of debris flows studied specifically.The analyses indicate that precipitation is the critical factor which causes the occurrence of debris flows on slope in Beibei District.The occurrence of debris flows is found to have a close relation with antecedent precipitation and one hour rainfall intensity.It is followed from the analysis of indexes that a debris flow may occur in Beibei District as the amount of one hour rainfall reaches 40 mm,the rainfall index,160,and the comprehensive index,650.