The storyline approach: a new way to analyse and improve flood event management

Common flood risk analyses often focus on direct impacts corresponding to the maximum depths of flood events. However, this information is not sufficient for risk communication, for the design of flood emergency plans and for the selection of risk management measures. For those issues, not only a static view of the maximum flood intensity is required, but also an understanding of the sequence of events from the rise of the threat to its recovery (including the action and reaction of actors). This paper discusses a new, additional approach to support flood risk management: the storyline approach, which serves to analyse the whole sequence of events during a flood. It starts from the initial rise of the flood threat, then describes the actual flooding and ends with the recovery from the flood impacts. It shows in a structured way the most important subsystems (water system, critical infrastructure system) and actors (water managers, local authorities, critical infrastructure operators, inhabitants) and their interactions. The application of the storyline approach to Dordrecht, the Netherlands, illustrates its use not only for flood event management, but also for the analysis of critical infrastructure vulnerability. The approach is designed to be applied in workshops with all relevant actors. The storylines support the communication of what might happen and help to develop consistent flood risk management strategies and emergency plans.