Coastal Digital Twin of the World’s Largest Tidal Flat System

Digital Twins of the Ocean aim to make information on the state of the ocean readily and interactively available to scientists as well as citizens, policy makers and other stakeholders. Many practical applications require – in particular – information on coastal regions. However, typical digital twins do not provide sufficient detail near the coast, because the model resolution is too coarse and these models lack processes that become relevant in shallow areas, e.g., sediment transport. We bridge this gap between the data provided by Digital Twins of the Ocean and the information needed for coastal applications by creating a Digital Twin of the Coast. The digital twin presented in this talk is a framework for regional downscaling of data from existing large-scale digital twins in combination with in-situ observations. Our Digital Twin of the Coast is based on a numerical coastal ocean model with refined mesh resolution along the coastline and in estuaries. This high resolution, which is further enhanced by subgrid technology, allows the fine tidal channels as well as coastal structures like dams and operational flood barriers to be represented in the model. The hydrodynamic model is coupled with a spectral wave model and includes transports of different sediment classes. We have implemented the digital twin for the Wadden Sea located in the south-eastern North Sea on the European continental shelf. The Wadden Sea is the world’s largest tidal flat system, stretching along the coasts of the Netherlands, Germany and Denmark. To protect its unique ecosystem and great biodiversity, the Wadden Sea has been declared a UNESCO World Heritage Site. The dense network of tide gauges in the Wadden Sea allows a reliable calibration of our numerical model. Our Digital Twin of the Coast is the first public database of consistent high-resolution data for the trilateral Wadden Sea. Thanks to the fast and intuitive web interface of our digital twin, the model data provided enable a wide range of coastal applications and support sustainable management. Applications currently implemented with our digital twin include ecological habitat calculator, sediment management, cable route planning and marine renewable energy.