关键词: 降雨型滑坡, 宣汉地区, 致灾因子, 确定性系数, 敏感性分析, 影响程度

Abstract: Xuanhan County is a region with well-developed geological hazard in Dazhou, Sichuan Province. To study the distribution and stability of landslides in this region, we analyzed the sensitivity of hazard-inducing factors closely related to landslide distribution and stability, inclusive of slope gradient, elevation, slope direction, lithology, water system and traffic road, in association with GIS technology and certainty factor based on field survey. Results conclude that landslide is mostly affected in 1) elevation between 400-1 000 m, mainly at 400-600 m; 2) slope gradient between 5°-25°, mainly at 5°-15°; 3) 800 m from water and road buffer zones, especially 400 m from road buffer zone. Furthermore, we adopted the susceptibility coefficient ratio and the susceptibility index to further analyze the influence of the factors on the distribution and stability of landslide. Result shows that slope gradient factor plays an important role in the stability of rainfall-induced landslide, but its influence on landslide distribution is weaker than that of traffic road factor.

Key words: rainfall-induced landslide, Xuanhan county, disaster factors, certainty factor, sensibility analysis, influence degree