Investigating Climate Change Impacts and Adaptation Strategies in German Estuaries

摘要

Due to sea level rise, estuaries are particularly affected by climate change. Besides sea level rise, changes in precipitation resulting in changing fresh water discharge and changes in storm activities can also have an impact on estuaries. The Elbe, Jade-Weser and Ems estuaries located in the German Bight (North Sea) are not only important ecosystems, they are also used as waterways. We need to know how climate change affects the estuaries in order to develop adaptation strategies. Generally, it is difficult to project climate change impacts on a local scale. The uncertainties involved can become very large. In this paper we describe an approach to determining the impacts of local climate change and to the investigation of adaptation measures without getting lost in the large range of uncertainty. First, we identify the main drivers which are assumed to be altered by climate change. In the next step we carry out sensitivity studies in which the main drivers are varied. For the sensitivity studies we use 3D-hydrodynamic numerical models. To test possible adaptation measures we repeat selected simulations which then include different adaptation measures. The results on local climate change impacts suggest that today's challenges are likely to become more acute. Higher salinities, increased upstream sediment transport, and higher water levels during storm surge must be expected. Adaptation measures can reduce these effects.