渝西典型丘陵区地质灾害易发性评价

Geo-hazard Susceptibility Assessment of Typical Hilly Area in Western Chongqing

重庆西部的丘陵区属于地质灾害发育密度较高的区域,掌握其地质灾害的易发性分布规律对于推动当地灾害预警体系建设至关重要.在分析渝西典型丘陵区孕灾地质环境条件的基础上,选取高程、地形起伏度、斜坡坡度、地灾点密度、距道路距离、距水系距离、工程地质岩组作为评价因子,采用信息量法和层次分析法构建地质灾害易发性评价指标体系和评价模型,并对渝西典型丘陵区的地质灾害易发性进行分区评价,同时对地质灾害易发性分区评价结果的精度和合理性进行了验证.结果表明:地质灾害高易发区主要分布于研究区的深丘区,其面积占研究区总面积的13.86%;地质灾害中易发区和低易发区在研究区的深丘区和中丘区中均有分布;研究区的浅丘平坝区以非易发区为主;经验证可知,本研究对研究区地质灾害易发性分区的评价结果与研究区地灾点的实际分布情况吻合度较高,说明本研究结果的精度较高,可作为当地灾害风险管控的依据.

The hilly area in western Chongqing belongs to the area with higher density of geological hazards.Mastering its distribution law of geo-hazard susceptibility is of vital importance to promoting the local construction of disaster warning system. Based on the analysis of disaster-pregnant geological conditions of typical hilly area in western Chongqing,assessment factors,including height,land relief,slope gradient,disaster point density,distance to road,distance to water system,and engineering geological group,were selected to establish the evaluation index system and evaluation model of geo-hazard susceptibility by information method and analytical hierarchy process.The zoning evaluation of geo-hazard susceptibility of typical hilly area in western Chongqing was carried out.Furthermore,accuracy and rationality of zoning evaluation results of geological hazard susceptibility were verified.The results indicate that the high-prone region of geological hazard is mainly distributed in the deep hilly area of the study area,and its area accounts for 13.86% of the total area of the study area. Medium-prone region and lowprone region of geological hazard are distributed in deep hilly area and medial hilly area. In addition,the shallowflat area in the study area is mainly non-prone region of geological disaster. It is verified that the geo-hazard susceptibility regionalization highly coincides with the actual distribution of disaster points in the study area. It shows that the accuracy of this study results is high,which can be used as the basis for local disaster risk control.