Hydrogeological modeling of the Roussillon coastal aquifer (France): stochastic inversion and analysis of future stresses

Abstract Global climate change-induced stresses on coastal water resources include use restrictions, saline intrusions, and permanently modifying or damaging regional resources. Groundwater in regions is often the only freshwater resource available, so an in-depth understanding of aquifer, aquifer’s response to change, essential for decision-makers. In this study, we focus aquifer Roussillon (southern France) by developing investigating a steady-state groundwater flow model (MODFLOW 6) calibrated with PEST++ Python interface (FloPy PyEmu). Model input boundary conditions are constrained various scenarios projections 2080, results predicting (and associated uncertainty) these external forcings. Using simple assumptions intrusion estimates, highlight both strong climatic anthropogenic impacts table. These drawdowns reaching several meters locally, seawater advancing locally hundred inland rising meters. Intrusions magnitude risk endangering exploited wells their sustainability. Our demonstrate critical importance properly characterizing geology its heterogeneity aquifers at because poor predictions may lead inappropriate decisions, putting risk, particularly environments.