Water exchange and sedimentation in an estuarine tidal harbor using three-dimensional simulation

Siltation is a permanent problem in harbors at tidal rivers and in estuaries requiring continuous maintenance dredging to guarantee safe navigation. Influencing currents and the sediment transport by alignment and specific structures can lead to a reduction of sedimentation. A three-dimensional numerical model was set up for the Weser River to simulate currents and the sediment transport in a brackish and tidal environment. The complex currents in a harbor in Bremerhaven were visualized, and the water exchange and the sedimentation were determined. Complex multidimensional boundary conditions were extracted from this regional model to run several detailed models with a different geometry, tidal condition, and salinity in a parametric study. The influence of these parameters on sedimentation in harbors was determined. Results of this parametric study were used to develop solutions to reduce sedimentation in harbors in a brackish tidal environment. The numerical model was capable of simulating the dominating hydrodynamic effects and sediment transport. The developed methodology can be used to minimize sedimentation in harbors.