County comprehensive geohazard modelling based on the grid maximum method

Abstract

Sichuan Province is characterized by great differences in topography, lithologic structure and frequent occurrence of various local disasters. Therefore, it is of great significance to carry out evaluations of the vulnerability of geological disasters. Rockfall and debris flows are landslides in a broad sense. Taking Danba County, Sichuan Province, as a case study, the spatial probability distributions of collapse, landslide and debris flow are comprehensively considered from the perspective of the susceptibility of different types of landslides to regional geological disasters. Based on ArcGIS, 10 key control factors of geological hazards, such as elevation and slope, were selected by a high-precision digital elevation model, and the susceptibility of comprehensive geological hazards was evaluated by an information content model. Finally, the Cell Statistics function of ArcGIS was used to realize the synthesis and comprehensive vulnerability of the maximum value method of multiple raster layers, and the ROC curve was further used to verify the accuracy of the vulnerability model of landslide categories in a single area. According to the natural break point method, the very low-, low-, medium-, high- and very high-prone areas were divided, and the high- and very high-prone areas were mainly concentrated in Zhanggu Town, Taipingqiao Township and Jiaju Town.This paper shows that the information model can evaluate a single type of geological hazard and that the grid maximum method is an effective evaluation method to obtain the comprehensive vulnerability.

Keywords

• comprehensive geohazard
• arcgis
• information value model
• grid maximum method
• susceptibility evaluation