InSAR-Derived Surface Deformation Patterns in Closed Coal Mines: Insights From Xuzhou, China

Accurate monitoring of surface deformation in closed coal mines is vital for hazard prevention and land management. This study investigates 2-D surface deformation and its spatiotemporal evolution in the closed Peicheng coal mine in Xuzhou, China, using 34 descending and 33 ascending TerraSAR-X images acquired between October 2017 and September 2019. The Stanford Method for Persistent Scatterers technique was applied to obtain line-of-sight deformation, which was further decomposed into vertical and horizontal components using the least squares method. Results reveal maximum subsidence and uplift rates of $-$21 and 12 mm/year, respectively, along with horizontal displacements up to 14 mm/year after mine closure. The deformation patterns resemble those observed in active mining areas; however, a key difference is that maximum horizontal movement occurs at uplift peaks rather than inflection points. These findings, combined with an analysis of goaf distribution, mining depth, and fault structures, provide insights into postmining ground behavior and support more effective management of closed mining sites.