A comparative study of comprehensive modeling systems for sediment transport in a curved open channel

In recent decades, a variety of morphodynamic model systems have been developed to improve our understanding of sediment transport and the resulting changes in riverbed topography. Despite progress in the description of physical processes, the degree of accuracy of morphodynamic model results remains difficult to assess and are also less than for hydrodynamics alone. In this paper, three different 2D morphodynamic systems have been applied to simulate a complex hydrodynamic and morphodynamic situation. These model systems were validated using data of sediment sorting and bed deformation conducted in a 180° channel bend under unsteady-flow conditions. The calculations obtained by each modeling system were compared with the available observed data. The simulated results showed that all applied morphodynamic models could precisely calculate the bed level changes and the areas of deposition and scour. However, the models are not efficient enough to predict the distribution of the mean grain size in the channel bend.