Analysis of Social Vulnerability to Earthquake Disasters in Mountainous Areas: A Case Study of Sixteen Cities along the Fault Zone in Sichuan Province, China

Given that most cities in Sichuan Province, China, are located in mountainous areas and are frequently affected by earthquakes, this study selected 16 mountainous cities in Sichuan Province. Based on the “exposure–sensitivity–coping capacity” framework, we constructed a social vulnerability assessment index system for earthquake disasters that aligns with the characteristics of mountainous regions. Weights were determined using the entropy weight–CRITIC method, and the improved TOPSIS method was used to calculate the social vulnerability index (SoVI) of each city for comparative analysis. Additionally, the social vulnerability maps were created using ArcGIS software to explore the spatial distribution characteristics. The study found that among the 16 mountainous cities, there is a noticeable spatial clustering of social vulnerability. Yajiang, Daofu, and Luhuo are identified as high–high clustering areas, while Jiulong, Luding, Shimian, and Hanyuan also exhibit high–high clustering. Kangding, Baoxing, and Wenchuan fall into low–low clustering areas. Additionally, coping capacity is the most significant factor influencing the social vulnerability of mountainous cities. After experiencing high-magnitude earthquakes, most mountainous cities have not improved their coping abilities and continue to exhibit high vulnerability, primarily due to high illiteracy rates, significant altitude variations, and poor economic conditions. This study provides a scientific basis for local governments to formulate disaster prevention and mitigation strategies, which help enhance the disaster resilience of mountainous cities and promote their sustainable development.