Presence, Characteristics and Dynamics of Estuarine, Tidal and Marine Dunes in the German Bight - EsTiMaDunes

• Applicant: Alice Lefebvre, Ph.D.
• Subject Area: Geology ; Oceanography ; Physical Geography
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 546809660

Under the action of river, tidal or other currents, sediment can be mobilised, transported and deposited to create undulations of the bed, collectively known as bedforms. Large bedforms are especially present in tidal rivers, estuaries and shallow continental shelves, where they form underwater dune fields, due to the strong hydrodynamics and sandy sediment found there. However, the presence, characteristics and dynamics of tidally-formed dunes is still poorly understood compared to those of river dunes. This is especially true in the German Bight and its estuaries, where dunes were only systematically characterised in 1972, apart from some spatially-limited studies since then. However, it is essential to identify dune presence, characteristics and dynamics for several fundamental (e.g. roughness computation, sediment transport assessment and prediction) and applied (e.g. channel depth management, offshore construction planning) reasons. The aim of the project EsTiMaDunes is to identify the presence, characteristics and dynamics of estuarine, tidal and marine dunes in the German Bight and the German tidal estuaries in order to establish relationship between bedform characteristics and environmental conditions in tidally-dominated environments. For this, the project has three defined objectives: (1) assess the presence, characteristics and migration of bedforms in the Weser Estuary, Elbe Estuary and Jade tidal inlet; (2) provide an up-to-date map of dune presence and size in the German Bight and relate these to hydrodynamics and sedimentological properties and (3) compare the characteristics of estuarine, tidal and marine dunes, define relevant descriptors and develop specific dune predictors. To do so, available bathymetric data from the German Bight and its estuaries will be analysed to derive dune presence, size (height and length), shape (in two and three dimensions) and dynamics. They will be compared to environmental data such as depth, sediment size or current strength. The project will result in an up-to-date mapping of underwater dunes in the German Bight and its estuaries, which can be used for fundamental and applied projects. It will also provide relations between dune characteristics and environmental variables, which can be used to predict bedform presence and properties in other tidally-dominated environments.

• DFG Programme: Research Grants
• Co-Investigators: Professorin Dr. Elda Miramontes García; Professor Dr. Christian Winter