Research On Land Surface Deformation Monitoring In Jilin Province Based On In Sar Time Series Analysis

The geological environment in Jilin Province is complex.Many years of coal mining history has caused large surface subsidence.The investigation found that the Songnen Plain in the northwest is a settlement-prone area.At present,land subsidence has become one of the major geological disasters in major cities,affecting society.Economic development and people's security.Therefore,the monitoring of land subsidence on a large spatial scale in Jilin Province,the division of the main settlement area,the determination of the settlement level and the range of subsidence radiation,and the analysis of the causes of settlement are extremely important for the development of the prevention and control of land subsidence in Jilin Province.This paper uses the Sentinel-1 data covering the four orbits of Jilin Province from the beginning of March 2016 to the end of October 2018.The northwest to southeast track numbers are: 3,105,32 and 134 respectively.The application of SBAS-InSAR to carry out research on surface subsidence under large-scale scale in Jilin Province,combined with PS-InSAR to verify Jiutai District,has the following conclusions.(1)Through SBAS technology,the surface monitoring of Jilin Province was carried out,and the results of cumulative deformation and annual average sedimentation rate of 100 m resolution were obtained.The results show that most of the regions are stable and undeformed,but there are three main deformation funnel zones,namely: In the central part of Songyuan area,the junction of Changchun and Jilin area and the central part of Baishan area,the largest cumulative settlement in the province is as high as 100.01 mm,and the maximum annual average settlement rate is 29.20mm/a.According to the requirements of PS technology,from the three main deformation funnel areas,the Jitai urban area was selected for PSI experiment.A total of 906 permanent scatterers were selected,and the cumulative deformation variables and annual average sedimentation rate results of the Jiutai area were obtained.The results showed that the ground in the study area The settlement phenomenon is widespread,and the maximum annual average sedimentation rate is within 37mm/a,and the annual average sedimentation rate in urban areas is 20mm/a.(2)In order to verify the reliability of SBAS measurement,the correlation coefficient is 78.1% by comparing the PS results,which indicates that the SBAS results have good internal accuracy in small areas,meet the requirements of InSAR measurement specifications,and then conform to the SBAS results and level results.Accuracy verification,the error m in the measurement difference is about 11.36 mm,which indicates that the SBAS result has centimeter-level monitoring accuracy in Changchun.(3)The results of SBAS experiments are compared with the earthquake tectonic structures,the distribution of debris flow and the degree of occurrence of debris,the degree of occurrence of ground fissures and the development of oil and gas in Jilin Province.The settlement area of Changchun and Jilin is obtained,which is located in the Yishu fault zone and the debris flow collapse.And the ground fissure is easy to occur and is the oil exploration area of CNPC,indicating that the surface deformation is greatly affected by this;the central subsidence area of Songyuan area is located in the Songyuan old earthquake area,and the central settlement area of Baishan area is located in the Tianchi volcanic area of Changbai Mountain,indicating the above two Settlement may be affected by the earthquake.This paper combines SBAS-InSAR and PS-InSAR technology to qualitatively and quantitatively analyze the ground subsidence situation in Jilin Province,and obtain the linear deformation field in Jilin Province.The results of ground subsidence are obtained,and the ground in Jilin Province is illustrated by comparison with historical data.Settlement is affected by geological disasters and exploration and mining.Through the research,the paper obtains the spatial distribution characteristics of land subsidence,the evolution law of settlement area and the factors of subsidence formation in Jilin Province,which provides certain reference value for the prevention and control of land subsidence in Jilin Province and future urban planning.