Reliability Analysis and Breach Modelling of Coastal and Estuarine Flood Defences

摘要

Failures of flood defences caused by extreme storm surges can result in severe flooding ofrnthe hinterland leading to loss of life and catastrophic damages. In order to quantify the risk of flooding, anrnintegrated risk analysis is being performed within the German ‘XtremRisK’ project. Within one subprojectrnof XtremRisK, reliability analyses and breach modelling of coastal and estuarine flood defences arernperformed. In this paper, the methods of the failure probability calculations of coastal and estuarine floodrndefence structures under the loading of extreme storm surges are discussed. Moreover, the analysis ofrndike breaches is introduced. Preliminary results of the failure probabilities and the breach modelling arernpresented exemplarily for estuarine dikes of the Elbe Estuary in the urban area of Hamburg, Germany.rnFurthermore, gaps in knowledge related to time-dependent failure mechanisms are addressed where anrnapproach is introduced to consider the unsteady conditions of storm surges implemented exemplarily forrnthe failure mechanisms of ‘wave overtopping’ and ‘overflow’. These results are put in context of an integratedrnrisk analysis approach used in XtremRisK.