Landslide Hazard Assessment in Yunyang County Based on Bayesian Method

Abstract

Landslides are one of the most frequent geological disasters in the Three Gorges Reservoir Area, and regional landslide risk assessment is of great significance for landslide risk prevention and control. This paper takes Yunyang County, Chongqing City, in the Three Gorges Reservoir Area as an example, selects seven evaluation factors including slope, aspect, shape, lithology, geological structure, river erosion, and human engineering activities, and uses the information value model and logistic regression model for landslide spatial probability prediction. Based on Bayesian statistics, a spatio-temporal model of landslide susceptibility index and disaster occurrence probability was established, combined with landslide disaster intensity index, to achieve the zoning evaluation of landslide hazard in Yunyang County. The results show that: (1) the predictive accuracy of the landslide susceptibility evaluation model is 0.730. (2) Based on the landslide events in Yunyang County in the past 20 years and the landslide spatial prediction results, the evaluation results show that the very high and high hazard areas cover an area of 1041.459 square kilometers, accounting for 58.69% of the total area. (3) Combined with the field investigation results, the very high and high hazard areas in Yunyang County are mainly distributed in areas where human activities are strong such as the main and tributary rivers of the Yangtze River and urban periphery, and it is recommended to implement key preventive and monitoring measures for landslide disasters.