Analysis Of Surface Deformation In The Area Affected By Fluctuating Zone Based On Time Series InSAR

Since the impoundment of the Three Gorges project,the reservoir water level fluctuates periodically and forms a permanent fluctuation zone.Due to the influence of water level fluctuating zone,the geological disasters along the slope bank are constantly emerging,which greatly increases the difficulty of geological disaster early warning and control.Surface deformation monitoring is the main technical means for early identification and real-time monitoring and analysis of geological hazards in reservoir area.As a new surface deformation monitoring technology developed in recent years,synthetic aperture radar interferometry has the characteristics of wide monitoring range and high monitoring density,which are not possessed by traditional surface deformation monitoring technology.It can obtain high-precision surface deformation information all day and all-weather,and has obvious advantages in large-scale and long-time slow surface deformation monitoring research.Based on the data of sentinel-1 radar satellite image and time-series InSAR technology,the surface deformation monitoring of the Three Gorges Reservoir Area in Fengjie County of Chongqing is carried out,and the results of surface deformation rate and deformation time series are obtained.The recognition and extraction of abnormal deformation area affected by the factors of the Three Gorges Reservoir area are completed The influence of fluctuating zone on regional surface deformation is analyzed.The main work of this paper is as follows(1)Based on time series InSAR technology,the surface deformation monitoring in the area affected by the fluctuating zone is carried out.Based on 63 sentinel-1 radar satellite image data,through the analysis of the characteristics of the study area and time series InSAR technology,SBAS InSAR technology is selected as the time series InSAR technology processing method in this paper,the time series InSAR technology processing flow is carried out,and the surface deformation monitoring of the study area from July 2018 to July 2020 is completed.(2)Based on multi-source data,identification and extraction of abnormal deformation in the affected area of fluctuating zone.Based on the monitoring results of surface deformation by time series InSAR technology,combined with geological data and optical images,the paper carried out the identification of abnormal deformation in the area affected by the fluctuating zone,and extracted 5 abnormal deformation areas affected by the fluctuating zone.(3)Analysis of the role of the fluctuation zone in the abnormal deformation.Combined with the environmental background of the study area,this paper analyzes the inducing factors of the regional surface deformation affected by the fluctuation zone;on this basis,by analyzing the process of the cumulative surface deformation and the evolution of the influencing factors with time,this paper summarizes the time variation characteristics of the abnormal deformation and the influencing factors,and analyzes the role of the fluctuation zone factors in the abnormal deformation.To sum up,the temporal InSAR technology can give full play to its advantages of all day,all-weather,wide range and high density in the surface deformation monitoring of the Three Gorges Reservoir Area in Fengjie County,Chongqing,and accurately calculate the large-scale and long-time slow surface deformation information in the study area;the abnormal deformation extraction technology combined with multi-source data can effectively identify the fluctuating zone The results show that the abnormal deformation in the affected area provides scientific support for the decision-making of slope bank prevention and control in the water level fluctuating zone;the factors of water level fluctuating zone have a significant impact on the slope bank deformation along the water level fluctuating zone,which is one of the leading factors of the slope bank abnormal deformation along the water level fluctuating zone.