Large-scale landslides around the reservoir area of Baihetan hydropower station in Southwest China: Analysis of the spatial distribution

Abstract

Southwest China is an area where geological hazards occur frequently. To develop a basic understanding of geological hazards in this region, the Baihetan hydropower station section of the Jinsha River basin and its surrounding region are selected as the study area. We compile a detailed inventory including the information of all large-scale landslides (i.e., >104 ​m2 in area) and analyze their typical characteristics. In the study region that covers an area of 6372.9 ​km2, we identify 3757 large-scale landslides with a total area of 1033.5 ​km2 and an average area of 275,097 ​m2 for each individual landslide. Specifically, the Qiaojia mega-landslide has the largest area, reaching 7,717,000 ​m2. These landslides are clustered and unevenly distributed, and those along rivers are characterized by zonal distribution. The analysis of the influencing factors of landslide occurrence shows that elevation, river valley (valley), fault, slope angle, and slope aspect have obvious influences on landslide occurrence. This study is not only beneficial for further understanding the development characteristics of landslides in mountainous areas of southwest China, but also provides basic data for subsequent landslide susceptibility mapping in this region.