Comparison of two models for bed load sediment transport in rivers

A one-dimension (1-D) and a two-dimension (2-D) bedload sediment transport models are presented and compared in this paper. Both models include the representation of a sediment mixture through two parameters describing a grain size-distribution: the median diameter and the standard deviation. For two laboratory experiments (one for erosion and one for deposition processes), measured and calculated bed elevation and sediment characteristics of the surface bed layer are compared. Using a proper calibration, both models can simulate the dynamics of some of the sediment parameters but not of all of them. Introducing an active layer of which the thickness can be adjusted offers the possibility to represent sediment processes in an easier way and thus to improve simulated results compared to measurements. The proposed representation of the sediment mixtures is sufficient to acceptably model the evolution of the size of the transported and deposited sediments along a channel and through time.