Long-term Morphodynamic Modelling of Coastal Evolution of the German Bight

To understand the hydrodynamics, sediment transport and morphological changes of the Jade tidal channel and the Jade Bay in the German Bight, Southern North Sea, a series of 2DH numerical morphodynamic models was set-up to simulate the morphological changes. Morphodynamic models are limited in terms of their predictive skills to reproduce mesoscale (temporal scales of years to decades, spatial scales of kilometers to tens of kilometers) erosion and deposition patterns of the Jade tidal channel due to the complex physical processes; uncertainty of topography changes and model parameterization. This paper investigates the use of a combination of model predictions and observations, which is referred to as an ‘optimization scheme’ in this study. The model predicted and observed morphological changes over a 10-year period are combined with weights inversely related to their relative errors. The updated morphological changes and updated bathymetry are achieved by minimizing the total errors of predictions and observations by using a cost function. The updated bathymetry was used as initial bathymetry for a second model simulation of the following 6-year period. The Brier Skill Scores (BSS) are adopted to assess the ability of model predictions. Preliminary results have shown that with updated initial bathymetry calculated from the optimization scheme, the model performance is improved. Success of applying optimization scheme on the morphodynamic model of Jade estuary has shown the potential of using combination of models and observations in future coastal area morphodynamic models.