Linking groundwater abstraction to anthropogenic land subsidence in Northern Madrid, Spain: A numerical modelling perspective

Unsustainable extraction of groundwater all over the world has led to a rapid decline in global groundwater levels, and this decline has been linked to land subsidence, a serious geohazard that poses a threat to present infrastructure, livelihoods and the built environment. Here, we particularly deal with the region of northern Madrid, where we have developed a numerical model to simulate the land subsidence driven by groundwater abstraction in the region. The numerical model is constrained, supplemented and evaluated using groundwater level data from monitoring wells in the region and land displacement data from satellite observations. From the amalgamation of what we see from the change in piezometric levels and simulated surface deformation, we conclude that the model represents subsidence during periods of intense abstraction and partial uplift in times of recovery phases when the groundwater levels rise. The numerical model necessarily helps us to form a connection as to how changes in groundwater levels in the Madrid region are translated and linked to ground motion and subsidence in the system. This, in the end, also helps us support and form better groundwater management scenarios and policies.