Chapter 2 – Developing a Holistic Approach to Assessing and Managing Coastal Flood Risk

It is increasingly recognized that a comprehensive understanding of the existing flood system is necessary to effectively manage coastal flood risk. This involves consideration of the social and ecological dimensions in addition to the hydrological aspects that have been the traditional focus of flood analysis. Social aspects are important, as they represent both the reason for flood management and the growth in exposure, as well as providing the context within which any decision will be made. Coastal species and habitats are inherently important for the flood management ecosystem services that they provide for flood management. The flood flow, depth, and extent determine the potential for flood damage. The conceptual model adopted here for coastal risk assessment is based on the Source-Pathway-Receptor-Consequence model, which is a simple linear conceptual model for representing flood systems and processes that lead to a particular flooding consequence. This approach is being used to evaluate how the Sources (waves, tides, storm surge, mean sea level, river discharge, run-off), through the Pathways (including coastal defenses), affect the Receptors (inland system), generating economic, social, and environmental Consequences. Collectively, this more holistic analysis of the flood system can identify likely trends in flood risk and the wide range of potential mitigation options embracing engineering, ecological, or socioeconomic measures, including hybrid combined approaches.