Abstract: In order to scientifically analyze the geological disaster susceptibility. This paper is based on the investigation and zoning of geological disasters in Helong City, and through the analysis of the distribution rules and influencing factors of geological disasters. Considering terrain, geology, meteorology, hydrology, soil vegetation and human engineering activities, combined with GIS technology and methods, 13 disaster causing factors including elevation, slope, aspect, curvature, lithology, distance from fault, rainfall, distance from water system, NDVI, soil texture, water erosion degree, population density and distance from road are extracted. Logistic regression and random forest model were used to evaluate the susceptibility of geological disasters, and the susceptibility zoning map was drawn. The result of random forest model shows: The very low susceptibility area is highest, reaching 56.98% of the total area, which is mostly located in the south of the study area; And the high and very high susceptibility areas account for up to 12.89%, which are located in the central and northeast, it is the key area for geological disaster prevention and management. NDVI, elevation, population density and rainfall are the main factors affecting disaster development, with a cumulative contribution rate of 58.12%. The ROC (receiver operating characteristic) curves and existing disaster density statistics of Logistic regression and random forest models show that the susceptibility zoning map are highly consistent with the actual disaster distribution, and their AUC (area under ROC curve) values are 0.856 and 0.907, respectively, which can achieve effective prediction and have good applicability. However, random forest model shows higher accuracy and stability, and its prediction performance is better than Logistic regression model.

Key words: geological disaster, susceptibility, random forest, Logistic regression analysis, GIS