Tidally dominated coasts are directly affected not only by projected rise in mean sea level, but also by changes in tidal dynamics due to sea level rise and bathymetric changes. By use of a hydrodynamic model, which covers the entire German Bight (South-Eastern North Sea), we analyse the effects of sea level rise and potential bathymetric changes in the Wadden Sea on tidal current velocities. The model results indicate that tidal current velocities in the tidal inlets and channels of the Wadden Sea are increased in response to sea level rise. This is explained by the increased ratio of tidal prism to tidal inlet cross-sectional area, which is due to the characteristic hypsometry of tidal basins in the Wadden Sea including wide and shallow tidal flats and relatively narrow tidal channels. The results further indicate that sea level rise decreases ebb dominance and increases flood dominance in tidal channels. This is, amongst others, related to a decreased intertidal area again demonstrating the strong interaction between tidal wave and tidal basin hypsometry in the Wadden Sea. The bathymetry scenario defined in this study includes elevated tidal flats and deepened tidal channels, which is considered a potential future situation under accelerated sea level rise. Application of these bathymetric changes to the model mostly compensates the effects of sea level rise. Furthermore, changes in current velocity due to the altered bathymetry are in the same order of magnitude as changes due to mean sea level rise. This highlights the significance of considering potential bathymetric changes in the Wadden Sea for regional projections of the tidal response to sea level rise.

中文翻译：

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潮汐对德国瓦登海海平面上升和水深变化的响应

潮汐主导的海岸不仅受到平均海平面预计上升的直接影响，而且还受到因海平面上升和水深变化引起的潮汐动力学变化的直接影响。通过使用涵盖整个德国海岸线（东南北海）的水动力模型，我们分析了瓦登海中海平面上升和潜在的测深变化对潮流速度的影响。模型结果表明，随着海平面上升，瓦登海潮汐进口和河道的潮流速度增加。这是由于潮汐棱镜与潮汐入口横截面积之比的增加而解释的，这是由于瓦登海潮汐盆地具有特征性的测压法，包括宽而浅的潮滩和相对狭窄的潮汐通道。结果还表明，海平面上升降低了潮汐带的退潮优势，并增加了洪水优势。除其他外，这与潮间带面积减小有关，这再次表明了瓦登海的潮汐和潮汐盆地测压法之间的强相互作用。本研究中定义的测深方案包括潮汐平面升高和潮汐通道加深，这被认为是海平面上升加速下的潜在未来情况。将这些测深更改应用到模型中，大部分可以补偿海平面上升的影响。此外，由于改变了测深法而引起的当前速度变化与由于平均海平面上升而引起的变化具有相同的数量级。