Land subsidence rebound detected via multi-temporal InSAR and ground truth data in Kalochori and Sindos regions, Northern Greece

Land subsidence in the broader Kalochori village region, at the west side of Thessaloniki, has been recorded since the early 1960s reaching gradually, next to the coastline, maximum values of 3-4 m. Temporal monitoring of terrain movements are exploited and combined with in-situ data to enhance understanding of the deformation signals. Persistent Scatterer Interferometry (PSI) and Small Baseline Subset (SBAS) multi-temporal Interferometric approach are applied for the analysis of a 20 year ERS 1, 2 and ENVISAT dataset The velocities estimated for the ERS dataset are in excellent accordance with previous studies, depicting subsidence with magnitude up to 35 mm/year. The intriguing output of the ENVISAT data archive (2003-2010) shows that, during the second decade, there was a change in motion trend, from subsidence to uplift. The fact that this uplifting trend of the second decade is well correlated with hydrogeological data of the area that show a synchronous rise of the aquifer level, verifies the dominating driver of the human factor concerning the land subsidence phenomena taking place the last 55 years. This conclusion is further supported by the fact that since 2007 the uplifting signal becomes smoother, following the smoother recovery of the aquifers. (C) 2016 Elsevier B.V. All rights reserved.