Staff

Dr. Yunzhu Yin

Description

Knowledge on potential future extremes is a crucial input for coastal protection and decision-making. Over the last decades, a number of investigations have focused on potential changes in mean and extreme sea levels for different regions of the world mostly concluding that extreme sea levels have increased at rates similar to the observed mean sea level (MSL). However, at the German Bight, non-linear increases in the extreme sea levels have been observed, also exceeding the observed rates of the MSL mostly attributable to non-linear dynamics of the tidal water level component. A feature neglected so far is, however, the ongoing but complex morphodynamic adjustment of the coastal bathymetry, which may cause both, increasing and decreasing future water levels. The subproject StAMSie aims at a statistical description of interactions between mean sea level changes, storm surges and morphodynamics.

The global and regional change in mean sea level and a change in storm surge levels are the most prominent changes expected to happen during the next decades. Based in coupled numerical models, we aim to investigate the interaction between between mean sea level changes, storm surges and morphodynamics along the German North Sea coast. Furthermore, we will try to quantify the underlying uncertainties.

Over the last decades, a number of investigations have focused on potential changes in mean and extreme sea levels for different regions of the world mostly concluding that extreme sea levels have increased at rates similar to the observed mean sea level (MSL). However, at the German Bight, non-linear increases in the extreme sea levels have been observed, also exceeding the observed rates of the MSL mostly attributable to non-linear dynamics of the tidal water level component.

A feature neglected so far is, however, the ongoing but complex morphodynamic adjustment of the coastal bathymetry, which may cause both, increasing and decreasing future water levels. The understanding of this interaction is necessary, to estimate the proper design heights of coastal protection systems. We will quantify the changes in surge levels for different MSL-scenarios (MSL + {50, 100, 150} cm). The investigations will be accomplished with the help of coupled 2D and 3D numerical models, to estimate the changes in surge levels and wave heights, but also the sediment dynamics.