Monitoring of Ground Deformation Along Shenzhen Metro System with Sentinel-1A SAR Imagery

The construction of the metro system alleviates the traffic congestion caused by urban expansion. However, at the same time, improper construction and operation activities would cause ground deformation that might lead to the urban hazards of ground cracks, building tilting, and ground collapse. Such ground deformation along the metro system can be generally measured by the interferometric synthetic aperture radar (InSAR) technique owning to the advantages of wide ground coverage and high accuracy of measurements. In this study, a general survey of the ground stability along the Shenzhen metro system has been carried out with the PS-InSAR technique using the 119 Sentinel-1A images from March 2017 to March 2021. The results show that, during the observation period, the ground deformation rate along the Shenzhen metro system is ranged from -26.2 mm/year to 9.3 mm/year. The deformation is mainly due to the consolidation of the reclamation land, construction activities of new metro lines, and geological changes.