Groundwater recharge

According to the hydro-geological meaning, a water volume supplying an aquifer over a given time. Rainfalls are mainly recharging groundwater. Unconfined groundwaters are recharged rather fast at each rainfall event. The rise in water levels and rainfall events are observed on a piezometric curve. Groundwater recharge occurs just after the saturation of soil by water through the direct infiltration of rainwater at the outcrop zones. The recharge of a confined groundwater is on the contrary much slower. Precipitation events are not or hardly visible on the piezometric curve. The rise in levels depends on the distance from the outcrop (longer conveyance time in soil and rocks), on local exchanges between aquifers, etc.