Functional analysis and hazard assessment in a debris-flow-prone torrential watershed: the case of the Réal torrent (Alpes-Maritimes, France)

Abstract

This paper presents a detailed functional analysis of the Réal torrent (Péone township, Alpes-Martitimes). Despite a relatively small watershed, this torrent is a large producer of debris flows. Its bed is characterized by a marked aggradation phenomenon. The performed analysis treats all aspects of the torrential processes: hydrology, identification of sedimentary sources, rheological and hydraulic characterization of debris flows, bed evolution since 1950, role of existing torrent control structures, and qualification of hazards. A scenario for future evolution of the torrential activity is proposed, and the main axes of a possible control and protection program are defined.