Perspectives de la dynamique fluviale au XXI^e siècle : l'exemple du bassin du Rhône

Fluvial dynamic outlook in twenty first century : the Rhone watershed example

¹ Sogreah
² Hydratec
³ Université Lyon II

Abstract

River geomorphologies and sediment transports have been modified according to different time scales. From post geological scale for glaciological evolutions, to small scales (several ten of years) for bed adjustments consecutive to local improvement works (embankment, gravel extractions, sediment deposited by an affluent). Some of perturbations caused by human actions during the last century may be practically definitive downstream of big reservoirs or in bypassed sections by power stations. Others will disappear progressively in rivers where discharges are not changed. In this case, consequences will be changes of river-beds (erosion banks and raising of bed). River sediments management during this century, will have to take into account possibilities of river systems to find themselves a new hydraulic continuity while preserving water uses and cross sections for flood flow.