Author(s): Alain Recking; Mohamad Nasr; Adele Johannot; Jean-Paul Travert

Linked Author(s): Alain Recking

Keywords: Bedload; Modelling

Abstract: When modelling rivers morphodynamics, it is not only important to model the bedload flux, but also the size of the transported material. Indeed, for a given flux, the resulting morphology will be different according to the size transported considered from sand to large boulders. In particular, the transportation of poorly sorted sediments in gravel bed rivers is still an open question. Partial transport is often considered, which means that all grains of a given size class are not in motion for a given shear stress. A few tools have been proposed for modelling this mobility. The common approach consists in using fractional bedload equation, which computes a bedload flux for each size of the mixture in presence. A new and promising modelling framework called GTM (General Threshold Model) has been proposed recently, and is tested here with new data collected an Alpine river. The comparison permits to confirm the model parameters, and inform us on some physical properties of the moving sediments.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022731

Year: 2022