Application of a multidisciplinary approach to assess consolidation in different geological layers at a local scale in Antwerp

Antwerp region in Belgium is suffering land subsidence at least since 1948 owing to a combination of human and natural factors. Before the current study, the spatial extent and magnitude of this subsidence had been detected and measured using the Persistent Scatterer Interferometry (PSI) technique. A 3D-finite-difference groundwater flow model using MODFLOW coupled to a 1D-geomechanical model (named SUB - Subsidence and aquifer system compaction) of 1 square kilometer located within the area where subsidence is observed. It was developed to estimate the consolidation that occurred over time in the different hydrogeological layers. Simulation results consist of time series of vertical deformation in the 9 layers of the model over 2007-2016. The total simulated displacements were compared to PSI surface measurements from ENVISAT data processed between 2007-2010. The simulated and observed values are fairly in agreement in the considered zone.