1D morphodynamic modelling using a simplified grain size description
Camenen, B. ; Beraud, C. ; Le Coz, J. ; Paquier, A.
Type de document
Article de revue scientifique à comité de lecture
Affiliation de l'auteur
IRSTEA LYON UR RIVERLY FRA ; CEFAS GBR ; IRSTEA LYON UR RIVERLY FRA ; IRSTEA LYON UR RIVERLY FRA
Résumé / Abstract
This paper introduces an 1D numerical code RubarBE for hydraulic and mobile-bed simulations. The code's ability to reproduce the downstream fining of a gravel-sand mixture in response to bed aggradation is tested against laboratory experiments. Unlike in most numerical models, grain size distribution in each sediment layer is not represented using a multi-class model, but using the median diameter d50 and a sorting coefficient σ. The comparison of numerical results with experimental data shows that the adaptation length La, classically used for non-equilibrium sediment transport, is an essential parameter of the model to accurately reproduce the evolution of the deposit front. Empirical laws for adjustments of d50 and σ are proposed to reproduce sediment sorting through two grain-size related adaptation lengths (Ld, Lσ ). They are scaled by the length of the reach in morphological equilibrium, which is a useful result for field applications.
Journal of Hydraulic Research, vol. 56, num. 2, p. 168 - 180