Monitoring and analysis of land subsidence in Beijing based on SBAS-InSAR Technology

The Beijing plain area with serious land subsidence is selected as the study area. The data of 26 scenic Sentinel-1A in this area from January 2020 to March 2021 are processed by SBAS-InSAR technology. Through the steps of small baseline combination, differential interference processing, track refining and re leveling, SBAS inversion and geological coding, the time series cumulative settlement and homogeneous strain rate in Beijing during January 2020 to March 2021 are finally inversed, The monitoring results show that the settlement in the east of Beijing is more serious, followed by the south. The settlement develops in the form of multi center funnel, and a relatively continuous settlement area has been formed. The subsidence areas are mainly distributed in Chaoyang, Shunyi and TongZhou areas, of which Chaoyang TongZhou area has the most serious subsidence, with the maximum annual average subsidence rate of 155.9mm/y, which is consistent with the current situation of rapid construction of groundwater demand in this area. Finally, the monitoring results are compared with the existing research results, and the consistency between them is high, which verifies the reliability and accuracy of sbas-insar technology in monitoring regional settlement.