基于InSAR技术的西宁北山地质灾害危险性评价

InSAR-based Hazard Assessment for Geological Hazards in Beishan Mountain,Xining

为探索使用InSAR技术提升地质灾害危险性评价精度的方法及其可行性,开展了西宁市北山地质灾害危险性评价研究工作。首先,在无人机野外地质调查的基础上,使用数字高程模型、工程地质、夜光遥感等多源数据,采用层次分析法分析了研究区地质灾害的易发性;然后,基于Sentinel-1A数据开展了D-InSAR地表变形分析,并建立了一种耦合地质灾害易发性与地表变形的地质灾害危险性评价模型,计算了西宁市北山地质灾害危险性空间分布值;最后,利用无人机航测技术和地面调查对研究区地质灾害高危险区域的地质灾害危险性进行验证。结果表明:相较于单一采用地质灾害易发性评价方法,采用本方法划分出的极高等级区域面积占比降低3.7%,但能多识别出60%的地质灾害,可见,基于InSAR技术,并将地表变形量耦合到地质灾害易发性评价中以提升地质灾害危险性评价精度的方法是可行和可靠的。

In order to explore the method and feasibility of using InSAR technology to improve the accuracy of geological hazard assessment,a case study of hazard assessment for geological hazard in Beishan Mountain,Xining City was carried out.First,on the basis of UAV field survey,multi-source data such as DEM,engineering geological data and luminous remote sensing data were used to analyze the susceptibility of geological hazard in the study area by the AHP method.Then,surface deformation analysis was carried out using Sentinel-1A data by D-InSAR technology,and a geological hazard assessment model coupled with surface deformation and susceptibility was established.By using this model,the spatial distribution value of geological hazard in Beishan Mountain,Xining City was calculated.Finally,field verification was conducted using umanned aerial vehicle survey and ground survey.The results show that compared with the evaluation method using only the geological hazards vulnerability,the area proportion of extremely high grade area is reduced by 3.7%,but 60% more geological hazards can be identified.Therefore,the method based on InSAR technology and coupling the surface deformation into the vulnerability of geological hazards to improve the accuracy of hazard assessment is feasible and reliable.