InSAR EGMS for Wide-Area Assessment of Extreme Rainfall-Related Modifications of Ground-Deformation Patterns: The Case of Vaia Rainstorm

Extreme rainfalls may have considerable impacts on the dynamics of deformations over an area, besides the catastrophic direct damages by flooding phenomena, etc. This study presents a framework for leveraging Copernicus European Ground Motion Service (EGMS) datasets to conduct a wide-area assessment of changes in spatiotemporal ground-deformation patterns. The analysis focuses on the Vaia storm (which occurred at the end of October 2018) as the key event and examines its impact on the most severely affected regions. The methodology involves trend analysis on segmented time-series and a novel approach for extraction of differential ground-deformation velocity (difference between pre-event and post-event velocities) in terms of quantity and typology (e.g., acceleration, deceleration, stabilization, etc.). The results are analyzed using statistical tools to provide a comprehensive view of the intense event’s effects on the deformation patterns across the study area, facilitating the identification of localized zones where the spatial impact patterns are most evident. The results showed the approach can be successfully applied to the EGMS datasets for wide-area assessment of the pattern modifications. Furthermore, the results of the case study showed that modifications due to the Vaia rainstorm in terms of differential velocity contain all the types of acceleration, deceleration, activation, and stabilization, as well as the high magnitudes observed over the area.