title: Coupling groundwater modeling and biological indicators for identifying river/aquifer exchanges.
abstract: Future climate changes and the resulting modifications in anthropogenic activities will alter the interactions between rivers and groundwater. The quantification of these hydraulic interactions is absolutely necessary for achieving sustainable water use and requires accurate analytical methodologies. This report proposes an interdisciplinary approach to the quantitative and qualitative characterization of hydraulic interactions between rivers and shallow aquifers, wherein it outlines the advantages of coupling groundwater modeling with biological markers. As a first step, we built independent diagnostic maps of hydrological exchanges at the sector scale on the basis of hydrogeological modeling and biological indicators. In a second step, these maps were compared to provide a quantitative and qualitative understanding of exchanges between groundwater and surface water. This comparison significantly improved the calibration of groundwater models through a better assessment of boundary zones. Our approach enabled us to identify the conditions under which it could be possible to use biological indicators instead of a large set of piezometric measures. The integration of such combined tools in a future decision support system will assist governmental authorities in proposing appropriate long-term water policies for the preservation of groundwater resources, such as for supplying potable water and/or mitigating pollution risks.
authors.affiliation: UMR 5600 Environnement Ville et Société, CNRS, Ecole Nationale Supérieure des Mines de Saint-Etienne, 158 Cours Fauriel, F-42023 Saint-Etienne Cedex 2, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Graillot
authors.affiliation: UMR 5600 Environnement Ville et Société, CNRS, Ecole Nationale Supérieure des Mines de Saint-Etienne, 158 Cours Fauriel, F-42023 Saint-Etienne Cedex 2, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Paran
authors.affiliation: UMR 5023 Ecologie des Hydrosystèmes Naturels et Anthropisés, CNRS, Université de Lyon, Université Lyon 1, 43 Boulevard du 11 novembre 1918, F-69622 Villeurbanne Cedex, France.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Bornette
authors.affiliation: UMR 5023 Ecologie des Hydrosystèmes Naturels et Anthropisés, CNRS, Université de Lyon, Université Lyon 1, 43 Boulevard du 11 novembre 1918, F-69622 Villeurbanne Cedex, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Marmonier
authors.affiliation: UMR 5023 Ecologie des Hydrosystèmes Naturels et Anthropisés, CNRS, Université de Lyon, Université Lyon 1, 43 Boulevard du 11 novembre 1918, F-69622 Villeurbanne Cedex, France ; UMR 6553 ECOBIO, Campus Beaulieu, CNRS, Université Rennes 1, 263 Avenue du Général Leclerc, F-35042 Rennes Cedex, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Piscart
authors.affiliation: Agence de l'eau Rhône-Méditerranée & Corse, 2-4 allée de Lodz, F-69363 Lyon, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Cadilhac
keywords: Aquatic invertebrates; Aquatic vegetation; Groundwater; Hydrological modeling; Hyporheic zone