Research on Subsidence Monitoring and Fault Reactivation in Mining Areas Using ESBAS-InSAR Technology

This study investigates the influence of fault reactivation on mining-induced surface subsidence, focusing on the 171107 working face of Liuzhuang Coal Mine in Fuyang City, Anhui Province. Using 29 Sentinel-1A ascending track SAR images acquired between January 8 and December 21, 2024. Surface deformation data were obtained through small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) and enhanced SBAS-InSAR (ESBAS-InSAR) techniques. The results show that the ESBAS-InSAR method significantly improves data coverage in low-coherence and high-deformation regions by synergistically inverting persistent scatterers (PS) and distributed scatterers (DS). The ESBAS-InSAR monitoring error increases near the subsidence center but is reduced after Gaussian curve fitting, with cumulative average errors in the azimuth and vertical directions of 15.8 mm and 17.04 mm, respectively. Profile analysis revealed that mining reactivated the F4 normal fault and the F1-2 reverse fault, leading to anomalous deformation zones with stepped and funnel-shaped patterns. This study highlights the importance of fault reactivation in shaping subsidence patterns and provides valuable insights for monitoring and early warning of geological hazards in coal mines.