DEVELOPMENT OF FRESHWATER MUDFLAT ZONES AND TIDAL CREEKS FOLLOWING AN INITIAL DESIGN SUPPORTED BY MORPHODYNAMIC MODELLING

As part of its flood protection strategy, the Senate of the the Free and Hanseatic City of Hamburg is planning dike relocations shifting inland as coherence planning measures. This is because raising the dike sometimes encroaches on the natural conservation area that needs protection and thus compensation, simply as the new dike geometry demands a larger area. One possibility of mitigating this impact is to increase the ecological value of the newly created riparian area. That can be achieved by the formation of freshwater mudflats with corresponding tidal creeks connected to the estuary, which develop on the floodplains created by the relocation of the dike. In this setting, anthropogenic tidal creeks are created with a connection to the tidally influenced River Elbe. Anticipating the morphological development at this location, the topographic design of these creeks must be planned in such a way that they remain in a stable morphodynamic equilibrium for the medium and long term. This is to ensure a lasting coherence effect of the planning measures.