InSAR-based monitoring of ground deformation in industrial areas and Its relationship with climate and groundwater

Continuous and effective monitoring of ground deformation in industrial areas can help ensure the safety of personnel and infrastructure. It can also provide invaluable information for managing the hazards associated with the potential failure of structures. Investigating triggering factors of ground deformation, such as earthquakes, volcanic activity, groundwater, and rainfall, can help understand and predict the velocity of deformation spatially to manage the associated risks better. Advanced remote sensing techniques, such as Interferometric Synthetic Aperture Radar (InSAR), allow effective ground deformation monitoring. In this study, the velocity of ground deformation is estimated for an industrial area in Catania, southern Italy, employing the InSAR time series of ERS-1/2 for years 1992–2000, Envisat for 2003–2010, and Sentinel‑1 for 2019–2023. The correlation between groundwater level and ground deformation was also studied in the earlier period when groundwater data was available. An abrupt change or jump was observed in the displacement time series at the end of 2018, probably due to the earthquake that occurred on December 26, 2018. The deformation velocity is estimated for 2018–2022 before and after jump removal for both vertical and horizontal displacement time series. The coherency and phase delay between the annual cycles of vertical displacement and weather time series across the study area are also estimated by the least-squares cross-spectral analysis for 2018–2022. The results indicate that the annual cycle of temperature is much more coherent with the ones in displacement than precipitation. In addition, the weather cycles are more in-phase with the displacement cycles toward the coast and almost out-of-phase, i.e., five to six months phase delay, toward the west part of the study area. Overall, the results demonstrate a general decrease in land subsidence across the region over the past decades, where the subsidence rate depends on several natural and anthropogenic factors, agreeing with earlier studies on the region. The results of this work can be useful in developing sustainable urban planning and adaptation strategies in coastal cities such as Catania.