A Tool for Studying the Ecology of HydrosystemsD. Peyrard, Ph. Vervier, S. Sauvage, J.M. Sánchez-Pérez, and M. Quintard
 Laboratoire d’Ecologie des Hydrosystèmes, Toulouse
 Institut de Mécanique des Fluides de Toulouse
The hyporheic zone is defined as an area where water and matter exchange through the sand, gravel, sediments and other permeable soils under and beside streams. Its impact on the hydro-system function is determined by the proportion of subsurface biogeochemical reactions and the fluxes of water exchanging with the hyporheic zone and flowing through the porous sediments.
The objective of our study is to develop and to apply a directly coupled model of hydraulic, transport and transformation that can be used for studying eco-hydrology of large river systems.