A NEW METHOD OF APPROACHING EXTREME STORM EVENTS FOR DESIGN LEVEL OR RISK ANALYSIS

Abstract

The North Sea coast is seriously threatened by storm surges. Climate change and its consequences, such as a rising sea level, will have serious effects on the safety of people and economic assets in coastal areas. Within the joint research project XtremRisK (bmbf-funded) the Agency of roads bridges and Waters of the Free and Hanseatic City of Hamburg developed a new method to calculate extreme storm surge events. The purpose of the research work, to calculated physically feasible extreme events is given consideration by detailed analyses of the single storm-surge components (tide, external surge from the Atlantic and wind surge) and their non-linear interactions by combining deterministic-empirical, statistical and numerical methods. The non-linear interactions can be comprised by hydrodynamic equations such as equation of momentum, continuity equation and volume balance. The claim to develop a comprehensive and physically feasible method is satisfied by the diversity of methodical approaches for analyzing the storm surge components and their interaction processes. Therefore a 2-method concept is developed on the basis of empirical and numerical approaches. The resultant new method is a new way of calculating extreme storm surges and can be used within new design concepts to calculate design level heights or could be a part of risk analysis