|
The area of Western Greece and the Peloponnese region show land deformations that can be triggered, for example, by seismic activity (e.g., Corinthian Gulf faults) and environmental factors (e.g., heavy rainfall). Land subsidence observed during the recent years within the Campus of the University of Patras in Northwestern Peloponnese confirms these spatiotemporal dynamics, with pronounced effects on the existing infrastructure and facilities. Here, we combined satellite remote sensing techniques and in situ geodetic monitoring to better understand these patterns and possible driving mechanisms. Regional-scale land deformations were quantified with active microwave remote sensing techniques (Persistent Scatterer Interferometric Synthetic Aperture Radar, PSInSAR) based on SAR data from the European Space Agency Sentinel-1 constellation of satellites. Land cover dynamics were characterized with high-resolution optical remote sensing observations (Normalized Difference Vegetation Index, NDVI; Planet Labs). The spatiotemporal Sentinel-1 SAR data were processed using the SNAP-StaMPS (SentiNel Application Platform - Stanford Method of Persistent Scatterer) integrated workflow for Persistent Scatterers Interferometry. The PSInSAR analysis resulted in regional-scale displacements of up to a few tens of mm per year. These displacements patterns were explored in tandem with possible land cover changes as detected with the NDVI spatiotemporal dynamics and further refined at the local scale with repeated field surveys during 2022 and 2023 at selected locations within the Campus of the University of Patras that were affected by land subsidence. The combination of remote sensing techniques, together with in situ ground monitoring, provides unique opportunities for monitoring ground deformation in almost real-time, facilitating thus the assessment of the response of infrastructures to such spatiotemporal changes.
|
