Hydro-system flow modelling for water resources management in the fractured and karstified chalk aquifer environment of Eastern Normandy

Abstract : Modelling complex groundwater/surface water flow in karstified chalk aquifer systems both requires appropriate modelling techniques and a good knowledge of geology and discontinuities (geological and hydrogeological). This is the case for the Avre River hydro-system for which a multi-layer geologic model was built, including geological and potential hydrogeological discontinuities, which then served as the basis to elaborate and calibrate the 3D hydro-system flow model. The latter through the calibrating process notably allowed explaining the presence of important spring arrays used for drinking water purposes in the central part of the basin, by the existence of a major impermeable intersecting faults system and highly fractured or karst conduits which developed along lineaments and faults.