Sediment Dynamics and Channel Adjustments Following Torrential Floods in an Upper Alpine Valley (Guil River, Southern French Alps)
Résumé
In the upper reaches of Alpine valleys, the shaping of active channels appears mostly
dependent upon hydroclimatic variability, as illustrated by the upper Guil River. In this valley,
recent land-use changes have reduced the channel capacity of the Guil River, and increased the
vulnerability of human installations to damage. In the frame of the implementation of a River
Scheme and a Flood Prevention Action Program, we try to improve our knowledge of
sediment transfers at the origin of disasters. Our analysis was carried after two high magnitude
low frequency hydroclimatic events (1957, 2000). It is based on desk and field data, account
for active-channel width and area, sinuosity and braiding indexes, engineering structures and
their variation in space and time. We show the major role played by the Guil tributaries in
supplying debris to zones with important assets. Finally, we discuss about the difficulty to
implement efficient management tools at a local scale.
Domaines
Géographie| Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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