Abstract:A 2DH hydrodynamic and sediment transport numerical model was established based on Delft3D. The validated model was applied to study the cultivated impact of the construction of harbor projects on the characteristics of hydrodynamics and sediment dynamics in the southwest of Bohai Bay and their interaction between Huanghua Harbor and Binzhou Harbor for nearly 20 years. The results indicate that the construction of harbor projects gradually divides the southwest of Bohai Bay into 3 independent regions. Under the wavecurrent interaction, the distributions of suspended sediment concentrations (SSC) over a tidal circle are similar to the ones under pure current, but the magnitude increases eight times. The contour of SSC is parallel to the coastline on account of the enhancement of alongshore current while the proportion of nearshore SSC in the west of Huanghua Harbor, middle of Huanghua Harbor and Binzhou Harbor and east of Binzhou Harbor is redistributed on account of the increase of sediment load during flood. Overall, after the construction harbor projects, the southwest part of Bohai Bay gradually reaches its new equilibrium of sediment transport. The project of Huanghua and Binzhou Harbor in 2012 and their planning project in 2020 can reduce the impact of sediment transport between harbors in normal weather and normal wave weather, respectively.