Abstract: According to the latest investigation and cataloguing data of geological hazards in Shijiba township of Baishuijiang River Basin in Longnan area, Gansu province, and on the basis of the analysis of the geological environment background and the characteristics of the development and distribution of geological hazards in the study area, the influence of disaster-causing factors on the development and distribution of geological hazards was analyzed comprehensively by using Arcgis 10.2 software platform. The disaster-causing factors included such as topography and geomorphy, geological structure, engineering geological rock formation, slope structure type, river erosion, vegetation cover, rainfall, earthquake and human engineering activities. By using information quantity method, the geo-hazard susceptibility and geo-hazard risk were assessed and zoned successfully. The method of combining information quantity method with qualitative evaluation method was used to realize the division of the susceptibility and risk assessment of debris flow geological hazards. The research results show that the area with high risk of landslides covers 14.22 km2, accounting for 3.30%; the area with medium risk of landslides covers 51.05 km2, accounting for 11.83%; the area with low risk of landslides covers 95.32 km2, accounting for 22.09%; the area with little probability of landslides covers 270.93 km2, accounting for 62.79% of the total study area. There are 17 high risk debris flows, 59 medium risk debris flows and 1 low risk debris flow. The assessment results can provide reference for the geo-hazard risk assessment and geo-hazard prevention and mitigation.

Key words: geotechnical engineering, Shijiba town in Longnan area, geo-hazards, information quantity method, susceptibility assessment, risk assessment

摘要： 依据甘肃陇南白水江流域石鸡坝乡幅地质灾害最新调查编录数据，通过对研究区地质环境背景及地质灾害发育分布特征分析研究，利用Arcgis10.2软件平台全面分析了致灾因子对地质灾害发育分布的影响，具体包括：地形地貌、地质构造、工程地质岩组、斜坡结构类型、河流侵蚀、植被覆盖、降雨、地震和人类工程活动等，采用信息量法进行了崩滑地质灾害易发性、危险性评价区划，采用信息量法和定性评价方法结合的方式实现了泥石流地质灾害易发性、危险性评价区划。研究结果表明：崩滑地质灾害危险性高区域面积14.22 km2，占3.30%；危险性中等区域面积51.05 km2，占11.83%；危险性低区域面积95.32 km2，占22.09%；危险性极低区域面积270.93 km2，占62.79%。17条泥石流危险性高，59条危险性中等，1条危险性低。评价结果可为区域地质灾害风险评价和防灾减灾提供参考依据。

关键词: 岩土工程, 陇南石鸡坝乡, 地质灾害, 信息量法, 易发性评价, 危险性评价