Water exchange, mixing and transient storage between a saturated karstic conduit and the surrounding aquifer: Groundwater flow modeling and inputs from stable water isotopes
Water exchanges between karstic conduit and aquifer are driven by pressure gradient. Isotopic signature determination and water head measurements were conducted on a karstic aquifer. Exchanges from aquifer water to conduit take place even in pseudo-steady state conditions. The model evidences steady-state exchanges evolving from recharge to discharge areas. With floods, these exchanges fluctuate around the equilibrium and create an underground hyporheic zone.