A review on the effects of boundary condition on sediment transport efficiency in the Lower Yellow River

For the Lower Yellow River,which has a major role of transferring sediment to the sea,the boundary condition has an important influence on the sediment transport efficiency. From the literature survey,this paper reviewed studies of the effects of boundary condition on sediment transport. An increasing number of studies have shown that the boundary condition and its evolutionary processes affect the spatial-temporal variation of the sediment transport efficiency. For different calculation methods of sediment transport,such as the hydrology method and hydrodynamics method,the influencing ways of boundary condition have both the difference and the relation. The mathematical comparison results show that the derivatives of sediment concentration of the two above mentioned methods are first order approximate. The key criterion used to check the effectiveness of simulation for sediment model is to determine whether the coupling effect between the sediment movement and bed deformation can be reflected. Seeing as how the sediment transport and bed deformation processes are very closely interlinked,it is proposed that the regulation of sediment transport efficiency can be studied from the aspect of the riverbed evolution process,potentially providing new insights and support for further studies.