Research On Landslide Susceptibility Evaluation Based On Time Series InSAR Technology

In recent years,sudden landslide disasters have occurred more and more frequently,which have had a serious impact on people’s living environment and the development of the national economy.The geological structure background in southeast Chongqing is relatively complex,with many mountains and large topography,leading to frequent occurrence of geological disasters such as landslides,which have brought great obstacles and even harm to the production and life of local people and the development of local economy.Time-series InSAR technology has been widely used in recent years to monitor small deformations on the surface and to conduct general surveys of landslides and other geological disasters.It has obvious advantages in monitoring landslides during creeping periods.The study area of this paper is the southeast area of Chongqing with complex topography.Using Sentinel-1A image provided by ESA as the data source,we discuss the time-series InSAR processing method suitable for the study area,and finally choose SBAS-InSAR technology to obtain deformation information.Using this to replace historical landslide points with poor timeliness as the basis of the research on susceptibility to landslides,the research on landslide susceptibility is carried out.Get the following conclusions:(1)Summarize the applicability of InSAR technology in the study area,and combine the topography and geomorphology of the study area to compare and analyze SBAS-InSAR technology and Stacking technology,and determine the best data processing method for obtaining deformation information in southeast Chongqing,namely SBAS-InSAR technology.The average rate of surface deformation from May2018 to February 2020 obtained by SBAS-InSAR technology shows the deformation information in the study area.According to the deformation characteristics when the landslide is formed,the acquired deformation points are screened and verified by historical landslide points.The reliability of the selected deformation point.Confirm that it can be used as the basic data for follow-up research.(2)According to the formation and development mechanism of the landslide,combined with the actual conditions of the study area’s difficulty and quantifiable data,and referring to the selection of evaluation factors at home and abroad,the landslide susceptibility evaluation factors were selected,and finally 8 Analyze the correlation between the selected evaluation factors,and determine the weight of each evaluation index by the analytic hierarchy process to determine the degree of influence of each evaluation factor on the deformation point of the landslide: elevation <terrain undulation <plane curvature <slope direction <Profile curvature<slope<distance water system<lithology.(3)Select the grid unit as the evaluation unit,construct a landslide susceptibility evaluation model combined with the information volume method,use the normalized weight and information volume to determine the information weight of each evaluation unit,and finally complete the landslide susceptibility evaluation.Draw the susceptibility zone map.Using historical landslide point data and field inspections to verify its zoning results,the results show that the extremely high and high-prone areas contain 83.04% of historical landslide points and 85.01% of the extracted deformation points,indicating that the use of time series InSAR to extract deformation information for landslides The feasibility of the method of susceptibility research.