Studies on the development of wind set-up in the river Elbe-further analyses

Hamburg, situated at the tidal Elbe River, has always been exposed to storm surges. Thus, reliable forecasts of water levels have always been of great importance for Hamburg ́s flood protection, but also for navigational needs. In order to improve Hamburg ́s own storm surge forecast system, the Hamburg Port Authority (HPA) analyzed the propagation of surges in the Elbe estuary. This study had been carried out within the joint research project ‘OPTEL – Wind set-up Studies and Development of an Operational Model of the Tidal River Elbe’. Although it has in general been known for a long time that surges are being deformed in the Elbe estuary, for instance by factors like the current bathymetry, the fresh water discharge or the height of the surge itself. By the OPTEL-studies, the influence of some parameters could be quantified for the first time. For instance, the investigations revealed that the local wind over the mouth of the estuary has in many cases a significant impact on the propagation of the surge and can increase its height by up to 50 cm. Thus, the possibility of a further improvement of high water forecasts for Hamburg is evident.