Development of a wind-based storm surge model for the German Bight and its application

Storm surges pose a significant risk to coastal areas, including the German Bight, where strong northwesterly winds lead to extreme water levels. We present a simple and efficient storm surge model for the German Bight using multiple linear regression with 10 m effective wind as the only predictor. We train and evaluate the model using historical skew surge data from 1959 to 2022, applying regularization techniques to improve prediction accuracy while maintaining the model’s simplicity. The final storm surge model consists of only five terms - the effective wind at various locations with different time lags within the North Sea region and an intercept. A performance assessment based on cross-validation yields a correlation of 0.88, matching the performance of much more complex models despite the simplicity of our approach. The model provides robust predictions for both moderate and extreme storm surges. Moreover, the model’s simplicity makes it particularly suitable for routinely estimating storm surges in climate simulations, even if the climate models provide a very limited number of output variables. Hence, the presented statistical storm surge model provides a valuable tool for evaluating storm surge risks under changing climate conditions. We apply the storm surge model to a multi-model ensemble of CMIP6 global climate simulations to explore the impact of anthropogenic climate change on storm surges in the German Bight. A particular focus is on potential changes in storm surge intensity.