Fluvial morphogenesis evolution of a mediterranean river: The example of the Durance fluvial system (south-eastern France).

Based on stratigraphical and sedimentological analysis of floodplain sedime nts, aerial photographies, ancient maps and texts preserved in local archiv es, the historical evolution of the Durance fluvial system (south-eastern F rance) is reconstructed. The amount of data allows to suggest a "model" of the evolution of the river during the 19th and the 20th centuries (decrease of floods frequency, reduction of fluvial bed, incision). Before these per iods of time morphological and hydrological crisis (the end of the 14th cen tury, 16th-19th centuries) may have alternate with period more quiet (15th century, as in the 20th century), althought the braided pattern never disap peared. This study stresses the originality of the evolution of a mediterra nean and mountainous river, and, in this context, the importance of climati c fluctuations on the fluvial system evolution.