L'évolution contemporaine de la bande active des principaux affluents de la Drôme, de l'Eygues et du Roubion (Préalpes du Sud, France). / The contemporary development of the active tract of the main tributaries of the Drôme, the Eygues and Roubion, in the southern pre-Alps of France.

摘要

This paper deals with the relationships between active channel evolution of the main tributaries of the Drôme, the Eygues and the Roubion rivers and changes that have affected watershed features since 1850. This study is based on a detailed analysis of land use changes and the history of torrent control works. It has been shown that tributaries are characterized by a generalised narrowing of the active channel which has been accelerated in the second half of the 20th century. This evolution is linked to the cumulative effects of a fluvial processes which induce a deconnec- tion of previous active alluvial surfaces and vegetation processes characterized by an increased of the potential for vegetation encroachment.