Research on the Application of SBAS-InSAR-based Surface Deformation Monitoring Technology for Precise Tracing of Groundwater Pollution Sources in Chemical Industrial Parks

Groundwater pollution in chemical industrial parks remains a serious environmental concern. Precise tracing of groundwater pollution sources is essential for achieving accurate, scientific and law-based pollution control, as well as safeguarding public health and ecological security. In this study, the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) technique was applied to monitor surface deformation in a chemical industrial park from 2017 to 2025. By integrating remote sensing data (surface deformation) and on-site investigation data (groundwater pollution survey results and anti-seepage investigation results by multi-methods), this study finds that: (1) The overall surface was stable, but localized subsidence ranges from -25 to 14 mm·a^-1, with a maximum cumulative value of approximately 190 mm during the monitoring period, mainly caused by industrial production and waste landfilling. (2) Compared with non-subsidence zones and uniform subsidence zones, areas characterized by uneven subsidence exhibited higher exceedance rates (91.07%) of groundwater contaminants, with the severe exceedance rate reaching 25.00%. Moreover, the groundwater sampling sites within enterprises exhibited excessive pollutants with industrial production wastewater, such as Al, Ni and extractable petroleum hydrocarbons (EPH), which indicates that leakage from damaged underground facilities is a major contributor to groundwater contamination. (3) Multiple cases of pipeline damage, deformation, and pond leakage were identified at uneven subsidence sites of typical enterprises monitored by SBAS-InSAR. This study suggests that surface deformation monitoring is valuable for identifying potential risks of underground infrastructure failure and is recommended as a pre-screening tool for precise groundwater pollution source tracing. The results of this study can provide guidance for the prevention and control of soil and groundwater pollution of chemical industrial parks.