Conflict and congruence in definitions of coastal flood risk

IntroductionClimate change and sea-level rise will exert additional environmental pressures on coastal flood defences in the UK and increase the expected annual damages from flooding (Sayers et al. 2015). I distinguish between various conceptions of risk, because responses to flood risk are built on the definition of “risk” taken to guide them.MethodsI sample literature from sociology, engineering, insurance and law to establish the definition and usage of “risk” across various fields. Risk definition, measurement, contributing factors and wider implications are identified for each perspective of risk.ResultsFigure 1 shows how perceptions of risk emerge from an interaction of environmental (physical) and social conditions. Even within one discipline, definitions of risk may vary because of different social and environmental drivers. Within insurance, for example, the risk for insurers is the correlation between insured’s characteristics and rate of claims-making (Abraham 1985), and thus may not be causally related to hazard occurrence or probability. For insureds, by contrast, the risk comprises chances of an event, its consequences, and the insurance costs, thus is composed both of strong social drivers and environmental factors.Figure 1 – Simplified diagram of risk perspectivesDiscussion and conclusionsThe varying socio-environmental grounding of flood-risk definitions affect how hazards are perceived and managed. A conceptual framework which consolidates the views on risk from various disciplines could highlight the sources and effects of divergence between definitions. To improve flood risk management under changing climate and social pressures, the Government and other groups must cooperate to build a shared understanding of what flood risk means to the UK, and how risks can be reduced. As a first step in this process, my PhD research will identify where the interactions between the various sources of flood risk are least understood, and develop a method to measure the impacts of policy that is based on conflicting understandings of risk.ReferencesAbraham, Kenneth S. “Efficiency and Fairness in Insurance Risk Classification.” Virginia Law Review 71, no. 3 (April 1985): 403.Sayers, P.B., M. Horritt, and E. Penning-Rowsell. “Climate Change Risk Assessment 2017: Projections of Future Flood Risk in the UK.” London: Committee on Climate Change, 2015