Susceptibility assessment of geological disasters based on an information value model: A case of Gulin County in Southeast Sichuan

Abstract

Geological disasters threaten the safety of people's lives and property in mountainous areas. The assessment of the susceptibility to geological disasters will help mountainous towns carry out planning and construction to avoid disaster risks. Gulin County in Southeast Sichuan was chosen as the study area. First, based on the ArcGIS spatial analysis, we select the seven evaluation factors of elevation, slope, lithology, slope structure, vegetation index, distance from fault and distance from road and use the information value model to assess the susceptibility of landslide and rockfall disasters. Furthermore, the ArcGIS cell statistics function was used to compare the information value of landslide and rockfall susceptibility, and a relatively larger information value was selected as the final information value of the raster unit to draw the comprehensive geological hazard susceptibility map of the study area. The susceptibility of geological disasters in Gulin County is divided into extremely low, low, medium, high and extremely high susceptibility zones by the natural breaks method. The results show that geological disasters are mainly distributed near faults and roads. Faults and human engineering activities are the main reasons for the frequent occurrence of geological disasters in the study area. The total area of high and extremely high susceptibility zones is 1 315.62 km2, accounting for 41.32% of the total area. The performance of the prediction model is tested by the ROC curve, and the AUC is 0.812 5, indicating that the comprehensive disaster susceptibility of Gulin County predicted by the raster maximum method is good.

Keywords

• rockfall
• landslide
• comprehensive geological disasters
• information value model
• susceptibility assessment