Flood risk assessment for Shoreline Management Planning

摘要

Modelling and decision-support tools are becoming available that will make it possible to conduct quantified risk-based appraisal of options for shoreline management. These methodologies form part of a hierarchy of risk-based methods that also include a national-scale methodology for flood risk-assessment and detailed methods for appraisal of individual coast protection and flood defence projects. This paper focuses on assessment of coastal flood risk as part of the Shoreline Management Planning process. A methodology is proposed for analysis of the performance and interaction of systems of defences that protect low-lying coastal areas from flooding. The methodology includes statistical analysis of waves and water levels, simplified reliability analysis of flood defence systems, rapid hydrodynamic modelling of inundation of coastal floodplains and evaluation of the economic and social impacts of flooding. The method is demonstrated in a flood risk analysis at Towyn Bay on the North Wales coast.