Author(s): Thorsten Albers; Nicole Von Lieberman
Linked Author(s):
Keywords: Morphodynamics; Tidal flats; Wadden sea; Sediments
Abstract: The areas of the wadden sea at the German North Sea coast are affected by intense morphodynamics. Especially in the estuaries a change of sedimentation and erosion occurs during different time scales. The permanent relocation of sediments challenges the decisionmakers and stakeholders. Their aim is to handle the changing bathymetry and to protect the sensitive environment of the estuary at the same time. To satisfy the requirements, which modern cargo ship industry demands, a concept for sediment management has to be developed. Therefore, an economic and ecologic balanced system is required. The Hamburg Port Authority (HPA) and the Federal Waterway Administration (WSV) presented recently a new concept for a sustainable development of the tidal area of the Elbe estuary (HPA & WSV, 2006). A main issue is to decrease the energy caused by tidal flow in the estuary. To achieve this aim structural actions within the estuary are considered. To evaluate these actions and their effects by means of a numerical model, an improved knowledge of the existing morphodynamic processes is required. Supported by the HPA the Institute of River and Coastal Engineering at the Hamburg University of Technology (TUHH) runs momentarily extensive measurements to collect data in the area “Neufelder Watt” at the mouth of the Elbe estuary. Since July 2006 water levels, flow velocities and flow directions have been recorded continuously. Also the concentration of suspended sediments was measured and recorded in high resolution within a cross section of the tidal creek “Neufelder Rinne”. The “Neufelder Rinne”, located in the research area, is a section of special interest due to its meaning for the hydrodynamics and morphodynamics of the wadden sea complex “Neufelder Watt”. Furthermore, waves are recorded and measured at various locations. In frequent intervals the bathymetry is determined by a multi-beam echo sounder attached to the research vessel, provided by the institute. A goal of the research project is to improve the understanding of morphodynamic processes on tidal flats. A special challenge is given by the location of the research area, in the centre of the Elbe estuary, and by the very low water depths. A model for the calculation of sediment transport in shallow water sections of wadden sea areas is going to be developed based on the results of the research project.
Year: 2007