Comparative study of multi-coupling models for geohazard risk assessment along mountain highway in the hilly areas of Jiangxi Province

Geological hazards along mountain highways affect the transportation and safety of residents in mountainous towns. Risk assessment comprehensively analyzes the contributing characteristics of the geological hazard-prone environment and triggering factors, which is crucial for highway disaster prevention and mitigation. Taking the lower section of the provincial highway Zhutoukengzi - Dukanxia road (S223) in Jiangxi Province as an example, four types of geologic hazard evaluation models were constructed based on frequency ratio (FR), coupled entropy index (EI), hierarchical analysis method (AHP) and the combination of the two (EI- AHP). For the development characteristics of the geological environment and geologic hazards along the highway, the natural slopes were selected and the geologic hazards are evaluated. AHP), to construct four kinds of geohazard risk evaluation models. For the geological environment and geohazard development characteristics along the highway, eight evaluation factors, such as natural slope, slope direction, topographic relief, slope morphology, slope cutting height, slope cutting gradient, stratigraphic lithology, and the relationship between faults and slopes were selected as the risk evaluation indexes, and the slope units were selected as the evaluation unit, and FR was used to quantify the evaluation factors, and AHP and EI were combined to calculate the evaluation factors. AHP and EI were used to calculate the subjective and objective weights of the evaluation factors, and the multi-coupling model based on FR was obtained by relying on the ArcGIS platform, and the geohazard hazard zoning maps along the highway with different evaluation models were drawn. The results show that the AUC values of the four evaluation models, FR, EI-FR, AHP-FR and EI-AHP-FR, are 0.746, 0.811, 0.836, 0.833, respectively, indicating that the AHP-FR evaluation model has the highest prediction accuracy and can effectively evaluate the risk of geologic hazards along the highway. The areas classified as high-risk, relatively high-risk, moderate-risk, relatively low-risk, and low-risk zones for the lower section of the Zhutoukengzi-Qukan road in Jiangxi Province were 0.295 km2, 0.570 km2, 1.509 km², 0.354 km², and 1.732 km², respectively, accounting for 6.66%, 12.79%, 33.86%, 7.97%, and 38.71% of the total area. This study provided a comprehensive zoning of potential geological hazards along the S223 road, offering scientific geological reference for the safe construction and operation of roads.