Modèle hydrosédimentologique des écoulements hyperconcentrés d'un petit torrent des Alpes du sud

An hydrosedimentologic model for hyperconcentrated flows of a small torrent in the southern Alps

CEMAGREF, Division Protection contre les Erosions, Domaine Universitaire, BP 76, 38402 St-Martin d'Hères Cedex, France Actuellement à l'Instituto de Pesquisas Hidràulicas de Porto Alegre, UFRGS, Brésil

Abstract

This paper expounds the principles of a global spatialized event model fitted to torrent floods. It reproduces both water and sediment flows through the catchments. The sediment transport formulas are specific to steep gradients. Furthermore, a formula for the break up of the armour layer has been introduced and a formula describing the turn of the bed load transport into suspension too. At the end, the paper exposes briefly the basin characteristics and the easurement devices, and compares the results of the model withthe observed data.