From Forecast to Action: Using Flood Impact Storylines to Optimize Mobile Levee Deployment and Emergency Response Strategies

Preparing for unprecedented natural hazard events is challenging because the lack of records and experience makes it impossible to know how such events will unfold. Repeated record-breaking floods in central Europe have increased awareness of the need for proactive planning beyond observed extremes. In a participatory approach involving firefighters and civil protection officers, we developed a method to identify locations where mobile levees can be deployed to protect critical infrastructure during extreme flood events. The approach is based on event storylines derived from synthetic design hydrographs, reforecast-based precipitation scenarios, and physical modeling of river discharge, inundation, and flood impacts. Optimized locations for mobile levee installation were identified by evaluating their effectiveness in reducing flood impacts and delaying inundation to gain time for evacuations. The approach shows that rapid and anticipatory deployment of mobile levees at selected weak points can delay flooding by several hours, providing valuable time for evacuation and the protection of critical infrastructure. The participatory approach proved to be valuable for decision-makers to exclude or prioritize strategies, raise awareness among actors, and train for event interventions with emergency services.