Based on the relevant research results of the coherent structure, the paper presents the mechanism of sediment transport during the process of turbulent bursting, ejecting and sweeping. Besides, the paper shows the detailed process of how a straight channel, due to the sediment particles moving from side walls into the water channel, changes into ith alternate side bars, and eventually into a meandering channel. Further, the paper presents the proposed critical incipient motion condition of the particles on the side wall by analyzing the forces exerted on the particles and be applying the turbulent eddy theories. The incipient motion condition is applied in Yellow River. The study showes that increasing bed roughness and flow depth are more helpful to the incipient motion of the sediment.
