Ground Surface Subsidence in Córdoba, Argentina, revealed by multitemporal SAR interferometry

Population growth in metropolitan areas and the need for infrastructure leads to a rapid and unplanned urbanization process. In Córdoba, Argentina, infrastructure problems have been recognized, such as breakage of houses and buildings, due to a combination of natural (soil instability) and anthropic factors (saturation of wastewater wells). In this study, Ground Surface Subsidence (GSS) was detected through multitemporal SAR (Synthetic Aperture Radar) Interferometry. Specifically, the Parallel Small BAseline Subset (P-SBAS) algorithm was used to process Sentinel 1 images acquired between 2015 and 2021. Main goal was to discover active subsidences for the first time, in places where deformations have already been detected only by cracking and rupture of infrastructure. Velocities of 3-7 cm/year were detected in peripheral neighborhoods such as Villa Libertador and Parque República, located in highly collapsible soils according to geotechnical reports. Results have revealed the magnitude of the problem and its impact on the structure of family homes. The applicability of this technique can be a complement to classical geotechnical approaches. Its relevance in the detection of latent geological hazards for decision-making by local actors is also discussed.