Using InSAR and GPR Techniques to Detect Subsidence: Application to the Coastal Area of “A Xunqueira” (NW Spain)

Climate change represents an important cause of subsidence, especially in coastal cities affected by changes surface water level and table. This paper presents a complementary study Interferometric Synthetic Aperture Radar (InSAR) Ground Penetrating (GPR) for the early detection subsidence sinkhole phenomena. The methodology was applied to urban area Galicia, northwest Spain (humid region), showing apparent signs building settlement during last two years. Two different InSAR methods are compared period from June 2021 March 2022: PSI (Persistent Scatterer Interferometry) SBAS (Small Baseline Subsets), average deformation velocities obtained resulted −3.0 mm/yr −4.1 mm/yr, respectively. Additional GPR data were collected January 2022 validate results, which detected agreement with persistent scatters method. is crucial information plan preventive maintenance.