Characterization of aquatic habitats and sedimentary dynamic on a regulated gravel bed river
Caractérisation des habitats aquatiques et de la dynamique sédimentaire d'une rivière régulée : l'exemple de la haute et basse vallée de l’Ain
Résumé
A research program to better understand the alluvial behavior of a regulated reach has been established on the Ain River. The objectives are to characterize aquatic habitats and analyze the physical factors that affect fish populations to restore sediment fluxes and maintain sustainable aquatic and riparian ecosystems of a shifting river. The lower Ain valley is marked by a sediment deficit downstream of the Allement dam. Various techniques have been deployed to establish the diagnosis: bathymetric restitution from aerial imagery, underwater particle size sampling from ground imagery, RFID sediment tracking, diachronic and synchronic statistical analysis of channel geometry. Morphological changes of the upper valley upstream of the Vouglans dam were also investigated. Management plans emerge from these studies, in particular to identify sediment sources to reintroduce gravel into the river while restoring former channels with high ecological potential.