Study on Sediment Transport Capacity of Different Flow Routes in the Yellow River Estuary

The sea-flow driven sediment transport capacity in the Yellow River Estuary is a complicated problem due to the dynamic interaction from river runoff, tidal current and waves. However, it is of a great significance for planning the flow routes into the sea. Two mathematical models for computing sediment transport and current are established based on the MIKE21 model in this chapter. The range of the large model covers the whole Bohai and the validity of the model is calibrated by the harmonic tidal components of observation data. Based on the open boundary conditions from the large model, the tidal currents and sediment transport processes in the Yellow River Estuary are studied by a small model with finer grids. The computational results show that three high tidal current zones exist with maximum current speed reaches 1.7 m/s. The alongshore current from Bohai Bay to Laizhou Bay is the dominant force to transport sediment. The analysis and calculated results show that net fluxes of sediment transported through both sides of 10 km width and into open sea in the routes of Diaokou River, Old Channel, current Qing8 Route, Maxinhe Route, Beicha Route and Shibahu Router are of about 51.04, 39.27, 29.94,17.75, 12.96 and 7.22%, comparing with the amount of sediment in the Lijin station, respectively. In the planning of the available flow routes, the DiaoKouhe Route has the largest sediment transport capacity. Interchangeable use of Qingshuigou routes including Qing8, Old channel and Beicha can be planned in the near future, Diaokou Route is a long-term consideration.