Analysis on the relationship between geological hazard and lithology , geological structure in Yibin City of Sichuan Province

Based on the large number, diverse types and uneven distribution of geological disasters in Yibin City, this study takes the coupling relationship between geological disaster and lithology - structure as a starting point. Through data collection, remote sensing interpretation and field investigation, this study analyzed and summarized the control effects of formation lithology and geological structure on geological disasters. The findings can provide scientific support for the zoning and deployment of geological disaster prevention and mitigation in Yibin City. The results show that geological disasters in Yibin City are closely related to lithology. Landslides （including unstable slopes）, collapses, and ground collapses are widely distributed in soft and hard massive layered clastic rock formations. Additionally, the transition zone between hard layered massive carbonate rock formation and soft hard clastic rock formation is conducive to the development of collapse. Debris flows are distributed in rock formations that are easily weathered and can provide rich material sources. Regional geological structure also influences the overall distribution of geological disasters, particularly the consistency between the strike of folds and faults and the overall distribution of geological disasters. The degree of geological disaster development varies with different local tectonic environments. In fold structures, geological disasters are primarily concentrated within 2 km of the fold core, with density increasing gradually as the distance from the fold core increases. In the fault structure, the density of geological disasters points increases as one approaches the fault plane, with the control effect of faults on geological disasters particularly evident within 1 km. This study recommends that the northern part of the study area, specifically Fengtan Village in Gaoxian County and Heping Village in Jiang’an County, prioritize landslide prevention and control measures, such as group prevention and group strategy. In contrast, the southern part should prioritize measures to prevent and control collapses and ground collapses, such as professional monitoring, relocation, and avoidance.