Time-Series Monitoring and Mechanism Analysis of Surface Subsidence in Changchun City Using E-PS-InSAR

Surface subsidence has grown to be a major geological problem for big and medium-sized cities in the context of urbanization and climate change. Changchun, a city of moderate size and rapid development, was chosen as the study region for this project. The Enhanced Permanent Scatterer Interferometric Synthetic Aperture Radar (E-PS-InSAR) technique was used based on Sentinel-1A imagery to gather time-series surface deformation information in order to perform long-term, high-precision monitoring and a mechanistic study of surface deformation in urban–rural integration areas. Subsequently, temperature and land-use type data were then integrated for a thorough investigation using techniques including correlation analysis and functional fitting. The following are the primary conclusions: (1) The E-PS-InSAR technique integrating both PS and DS targets can significantly improve the density of monitoring points compared to traditional methods, providing the complete spatial coverage. (2) Changchun has an average annual subsidence rate of −0.14 mm and an average cumulative subsidence of −0.08 mm. The highest cumulative subsidence is up to −41.31 mm, and the maximum subsidence rate is −17.27 mm/yr. (3) Surface subsidence was correlated with land use types, and cultivated land was the primary contributor to subsidence. (4) Surface subsidence exhibits distinct seasonal fluctuations, and climatic factors exhibit a lagged influence on surface subsidence. These results are crucial for safe infrastructure operation, urban planning, and promptly preventing geological dangers in mid-sized cities.