标题：Debris-flow functioning and their contribution to sedimentary budgets: the Peynin subcatchment of the Guil River (Upper Queyras, Southern French Alps)
摘要：The Peynin catchment (15 km2
) is prone to catastrophic floods (June 1957 – Recurrence Interval
R.I.>100 yr), June 2000 (R.I.-30 yr) with serious damages to infrastructure and buildings located at the
outlet. In this paper, PIT tags tracers and Vensim modelling software are used to better assess the sediment
delivery unsteadiness, and more specifically to evaluate the respective role of geomorphological processes
on sediment supply during flood event. For the last 20 years, our results highlight a significant variability in
sediment delivery from a tributary to another one. According to our studies, we suppose that two torrential
tributaries of the Peynin river, the Peyronnelle and Three Arbres subcatchments (<2 km2, representing
<15% of the Peynin catchment area) are responsible of 80% of the sediments observed at the outlet of the
catchment. Several processes take a part of these sediment transfers, but the efficiency of the sediment
cascade in this catchment can be explained by a strong connectivity between sediment erosion area and the
main channel of the catchment. Debris and torrential flows triggered during high intensity meteorological
event are actually effectively coupled in space and time and guarantee an important sediment supply able to
reload the downstream part of the sediment cascade. Recent climate trends, marked by extremes, suggest
consequently more damaging events to come, in a context of increasing vulnerable assets.
