太行山区地质灾害风险性评价——以河北省涉县为例

Risk Assessment of Geologic Hazard in Taihang Mountain Taking Shexian County in Hebei Province As an Example

研究太行山区地质灾害的致灾因子并进行风险性评价,为该区域防灾减灾、应急预案设计提供参考。以河北省太行山区地质灾害多发区涉县为研究对象,基于地理信息系统(GIS)技术分析平台,选取坡度、地层岩性、断层、植被覆盖、年降雨量、土地效益、人口密度等因子作为评价指标,采用层次分析法,从地质灾害的危险性和易损性2个方面进行综合分析,构建太行山区地质灾害多发区的地质灾害风险性评价模型,得到涉县的地质灾害风险性等级分区图。结果显示:涉县地质灾害高风险区、中高风险区主要分布在西部清漳河和中部邯长铁路沿线一带,高、中高风险区面积占涉县总面积的比例分别为17%和22%,该区域风险性较高的原因是自然条件脆弱以及人类经济活动影响剧烈;中、低风险区主要分布在东北部和东南部地区,中、低风险区面积占涉县总面积的比例分别为40%和21%,该地区虽然地势较高,但高程差小、岩性坚硬,植被覆盖度高,人类活动干扰不明显,风险性较低。通过3S技术可以快速提取地形地貌、地表覆被、地质、水文、人文条件等自然和社会经济信息,在此基础上部署与安排防灾减灾工作有一定的科学性、准确性和实用性。

The research and risk assessment of the causing factors of geologic hazard in Taihang Mountain could provide reference for hazard prevention and mitigation and emergency plan design.Taking Shexian County in Hebei Province,a geological hazard prone area in Taihang Mountain,as the research object,based on GIS technology analysis platform,factors such as slope,formation lithology,fault,vegetation cover,annual rainfall,land benefit,population density and so on were selected as the evaluation indexes,and AHP was adopted to carry out comprehensive analysis from two aspects of geological hazard risk and vulnerability,so as to construct a geological hazard risk assessment model of the geological hazardprone area in Taihang Mountain and obtain the geological hazard risk grade zoning map of Shexian.The results showed that high-risk areas and medium-high-risk areas were mainly distributed along the west of Qingzhang River and the middle of Hanchang railway line.The high-risk areas and the medium-high-risk areasaccounted for 17%and 22% of the total area of Shexian County,respectively.The higher risk was caused by the fragile natural conditions and the severe impact of human economic activities.The medium and low risk areas were mainly distributed in the northeast and southeast.The medium risk area and the low risk area accounted for 40%and 21%of the total area of Shexian County,respectively.Although the terrain was relatively higher,the elevation difference was small,the lithology was hard,the vegetation coverage was high,the interference of human activities was not obvious,and the risk was low.Through 3S technology,the natural and social economic information such as topography,surface cover,geology,hydrology and human conditions can be rapidly extracted.On this basis,it is scientific,accurate and practical to deploy and arrange hazard prevention and mitigation work.