2D Numerical simulation for the formation of channel pattern

A sediment transport and bed morphology model considering the secondary flow and non-uniform of sediment with armored beds was established based on the 2D depth-averaged hydrodynamic model previously developed in this paper. A simple simulation method considering the influence of river bend was adopted in the non-cohesive bank erosion, so that it is capable to simulate the evolution of sand bars. A 180° bend with a constant radius under unsteady flow conditions and the laboratory experiments of Friedkin on the initiation and evolution processes of non-cohesive meandering channels was simulated with the model, the results agree well with field measurements, it demonstrates the extended model can reflect the formation mechanism of river bend. The extended model can be applied to simulate fluvial processes to study the transformation mechanism of alluvial rivers.