Flood Risk Management: Analysis of Evacuation Process

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Natural Hazard Science. Please check back later for the full article. Globally, floods cause widespread damage, especially in densely populated areas exposed to heavy land use. As a result, enormous financial expenditure is invested in flood protection and the mitigation of flood-related effects. Decisions on the allocation of resources to ensure flood protection are made on the determination of the costs entailed and the expected benefits that such actions may bring. From the economic point of view, the outlays incurred for flood protection should be outweighed by the expected results. For this reason, flood risk management is very important. Mitigation of flood-related loss should take into account a comprehensive spectrum of actions, from prevention and education, through measures taken during a flood, to strategies that help people return to normality once the disaster is over. In the 21st century there has been a radical change in the approach to the issue of flood protection (as seen in the 2007 Floods Directive)—it is no longer believed that there is such a thing as complete protection against flood, but that the damage and loss floods inflict can be mitigated, and since floods cannot be completely eradicated, societies must learn how to live with them. In the event of a flood, pre-prepared procedures to counteract and mitigate the effects of the disaster are followed, including evacuation of people and movable property from affected areas. Evacuation planning is meant to reduce the number of disaster-related fatalities and material losses. Crucially, this type of planning requires a well-defined, optimum evacuation policy for people/households within flood hazard areas. In addition, evacuation modeling is particularly important for authorities, planners, and other experts managing the process of evacuation, as it allows for more effective relocation of evacuees. Modeling can also facilitate the identification of bottlenecks within the transport system prior to the occurrence of a disaster, that is, the impact of flood-related road closures and the effects a phased evacuation has on traffic load, among other things, can be determined. Furthermore, not only may the ability to model alternative evacuation scenarios lead to the establishment of appropriate policies, evacuation strategies, and contingency plans, but it might also facilitate better communication and information flow.