金沙江是长江的上游河段,处于青藏高原东南缘向云贵高原和四川盆地的过渡部位,区内地质环境差异大,新构造运动强烈,生态环境脆弱,滑坡灾害频发。为研究金沙江上游滑坡灾害的发育分布特征及影响因素,以苏洼龙—奔子栏河段为例,通过现场调研,并搜集已有资料,对该河段发育的32处滑坡灾害进行统计分析。分析结果表明:①滑坡灾害空间分布不均,在苏洼龙—奔子栏河段滑坡灾害主要集中于金沙江干流王大龙、茂顶、斯木达和支流定曲河古学乡4个区域;②滑坡灾害以巨型、大型深层顺向基岩滑坡为主,第四系堆积体滑坡较少;③苏洼龙—奔子栏河段滑坡形成时代较早,加之新构造运动强烈,河流下切速度较快,因此呈现出滑坡剪出口高程明显高于河流水位高程的特征;④滑坡灾害与该河段地形地貌、地层岩性、地质构造、岸坡结构等地质环境条件密切相关,其中30°～35°坡度范围内的山体、绿片岩与蛇绿岩群、断裂带1km范围内和顺向岸坡条件下最容易产生滑坡灾害。

Jinsha River, upper reach of Changjiang River, is located in the transition zone of the southeast Qinghai-Tibet Plateau, Yunnan-Guizhou Plateau and Sichuan Basin. In this area, geological environment is variable with intense neotectonics movement, fragile ecosystem and frequent landslides. In order to study the occurrence and distribution characteristics and its influencing factors, we take Suwalong-Benzilan reach of the Jinsha River as a case study. Through field geological investigations and existing data, we analyze 32 landslides in the reach. The research results are shown as follows: 1) the spatial distribution of landslide is uneven, mainly in four regions, namely Wangdalong, Maoding, and Simuda in the mainstream of Jinsha River, and Guxue township in the branch of Jinsha River; 2) landslides are mainly huge and large-scale types whose attitudes are in agreement with deep bedrock, but few landslides exist in quaternary deposits;3) landslides at Suwalong-Benzilan reach of the Jinsha River formed in earlier geological ages, and elevation of shear outlet of the landslides is higher than that of water level of the river due to intensive neotectonic movement and rapid river incision rate; 4) landslide is relevant to geological environment conditions such as landform, lithologic character, geologic structure and river bank structure, in particular, landslide disasters easily occur in conditions of mountain bodies with 30° to 35°slope gradient, greenschist and ophiolite rock mass, fault areas within 1 kilometer and normal river bank slopes.