Research On Surface Deformation Based On Sentinel-1 Xianshuihe Fault Belt

Traditional surface deformation monitoring methods have the disadvantages of large workload,time-consuming and laborious,and high cost.Interferometric Synthetic Aperture Radar(InSAR)technology has the advantages of easy monitoring,high precision,low cost and wide range.It provides a new way of space-to-ground observation for revealing the temporal and spatial evolution of geoscience phenomena,especially in The widespread application of monitoring geological disasters such as surface deformation and landslide deformation has become an indispensable means of monitoring.The Xianshuihe fault zone is a left-lateral strike-slip fault zone in the southeastern margin of the Qinghai-Xizang Plateau.It has complex structure and high frequency of strong earthquakes.It is one of the most active fault zones in China and has attracted the attention of many scholars at home and abroad.The research results are rich,and the deformation research on the vertical side is less.In order to study the deformation characteristics of the surface in the vertical direction,and also to reduce the damage caused by earthquake disasters as much as possible,it is necessary to deeply understand the fresh water.The tectonic movement characteristics of the river fault zone are longterm monitoring of the surface deformation in the vertical direction.This paper takes the Zheduotang section,the Selaha-Kangding section,the Xuemenkan-Kangding section and the Moxi section at the southern end of the Xianshuihe fault zone as the study area,and will use the Sentinel-1 satellite in August 2017-The SAR image obtained during September 2018 was used as the data source,and the surface deformation information of the study area was extracted by InSAR technology.The main research contents and conclusions of this paper are as follows:(1)Using the two-track D-InSAR technique to extract the surface deformation of the Xianshuihe fault zone,the deformation characteristics are analyzed based on the motion characteristics of the fault zone.The results show that the overall deformation of the study area is mainly sedimentation,and its deformation variables are not more than 15 mm.The settlement area is mainly concentrated in the northwest direction to the southeast direction;the local area is uplifted,and the uplift area is distributed in the northeast and middle edges.The area and the southwestern part of the area;the SelahaKangding fault zone and the Kangding-Snowenkan fault zone and the Moxi fault zone form a symmetrical fracture motion.(2)Using SBAS-InSAR technology to extract the time series deformation rate of the study area and analyze the deformation rate characteristics.The results show that the deformation rate distribution range is-15~5mm/a,and the positive rate is mainly distributed in the northeast and the edge of the middle,the southeast and the west of the northwest.The deformation rate of the other regions is almost negative.At the same time,based on the time series deformation rate results,the transverse cross-cutting fault zone and the analysis of the section line show that the two discs of the Xianshuihe fault zone are smaller.(3)Comparing the surface deformation results with the time series deformation rate,the analysis results show that the dimensions and accuracy levels of the two are inconsistent,but the overall deformation trend is consistent.Based on the above research,InSAR technology has a certain reliability for monitoring and analyzing surface deformation.It is found that during the period from August 2017 to September 2018,the surface deformation of the Xianshuihe fault zone is small,and the dislocation of the fault zone is not obvious.It fully demonstrates that its tectonic activities are stable during this period.At the same time,the research results of this paper provide favorable data support for the subsequent geological survey,deformation monitoring and natural disaster early warning and prevention.