The record storm surge in October 2023 caused severe damage to the German Baltic coast. Effective adaptation scenarios to rising sea levels are therefore becoming increasingly urgent. In two recent studies, researchers at Kiel University have modelled both the flooding extent along the Baltic Sea coastal areas and, for the first time, two possible upgrades for current dike lines in high resolution. They modelled various storm surge and sea level rise scenarios. Their results show that, based on the current dike line, neither an increase nor managed realignment, i.e. controlled breaching of seaward defences and relocation of primary defence line further inland, as a nature-based solution can be sufficient to protect people, infrastructure or buildings to significantly reduce the risk of flooding along the German Baltic Sea coast by the year 2100. In the model, the risk for the population compared to today's existing coastal protection was only reduced by a maximum of 26% for the scenario of managed realignmen. Their results were published on 24 November in the journal Communications Earth & Environment and at the beginning of September in Natural Hazards and Earth System Sciences.
"The majority of our simulated flooding areas are located in Mecklenburg-Western Pomerania, with the hotspots in the lagoons of Fischland-Darß-Zingst, Rügen, Usedom and the Peene estuary. In Schleswig-Holstein, the Flensburg Fjord, Eckernförde Bay, Fehmarn, Travemünde and Lübeck are particularly affected", says first author Dr Joshua Kiesel, postdoctoral researcher in the Coastal Risks and Sea Level Rise working group at the Institute of Geography at Kiel University. Professor Athanasios Vafeidis, co-author of both studies and member of the research priority area Kiel Marine Science (KMS) at Kiel University, leads the working group. "Today, we can still decide for a large part of the German Baltic Sea coast what an adaptation might look like in the future. The known disadvantages of existing dikes should definitely be taken into account”, says Vafeidis. According to the researcher of Kiel University, this is also crucial for protection against future extreme events, which are very likely to become more
frequent
Read more at: Kiel University
Nature-based adaptation options in the event of rising sea levels are attracting increasing attention. One example of this is managed realignment, which aims to create a natural buffer zone between the sea and the dike. (© Joshua Kiesel, Kiel University)