Analysis of Geological Hazard Risk Regionalization in Southern Jiangxi Province

The mountainous and hilly terrain of the southern Jiangxi (Gan Nan) region is widely distributed, with a total of 10,417 geological hazards, which pose a significant threat to the safety of lives and property. Therefore, conducting geological hazard risk assessments for this region is crucial for prediction, forecasting, and disaster reduction. This study, based on detailed geological hazard survey data at a 1∶50,000 scale, analyzes the disaster-prone background and distribution characteristics of geological hazards and the main control factors in southern Jiangxi. On this basis, six susceptibility evaluation factors were identified: slope, slope structure, engineering geological rock group, soil thickness, geomorphological units, and the density of previously occurred disaster points. A comprehensive index method was used for susceptibility assessment. Additionally, a hazard assessment was conducted for the study area, taking into account the 20-year return maximum 24-hour rainfall and slope-cutting-induced factors. The risk assessment was further refined by incorporating vulnerability analysis. The results show that the main types of disasters in the study area are small-scale shallow landslides and debris flows, which predominantly occur in metamorphic and igneous rock residual slope deposits, with rainfall and slope cutting activities being the dominant controlling factors. The proportions of the extremely high-risk, high-risk, medium-risk, and low-risk areas in southern Jiangxi are 0.8%, 45.7%, 40.3%, and 13.2%, respectively. The extremely high-risk and high-risk zones are mainly concentrated in the mountainous areas of Shicheng County and Xingguo County, while the medium-risk and low-risk zones are primarily found in the flat areas such as plains and hills. The findings of this study provide important guidance for the risk prevention and management of geological hazards in this region and similar geological environments.