A new model for predicting bed evolution in estuarine area and its application in yellow river delta

This article discusses the process of sediment transport and proposes a morphological model to predict the bed evolution in estuaries. The hydrodynamic module is based on an existent model-Depth Integrated Velocity And Solute Transport (DIVAST) and the wetting and drying method is adopted to deal with the moving boundary. Both cohesive sediment and non-cohesive sediment are taken into consideration in the sediment transport module with the capability of simulating the transport of graded sediments under non-equilibrium conditions. The fall velocity of the suspended sediment is modified in the present model due to the high sediment concentration. A 3-layer approach is adopted to simulate the variations of sediment gradations of bed materials. Furthermore, the model is used to simulate the bed evolution in the Yellow River Delta (YRD) from 1992 to 1995. Field data are used to calibrate the parameters. The numerical results show how the morphology was developed in the Yellow River Estuary with a good agreement with the field data.