Flood risk mapping practice must change to support fair and informed decisions

Flood risk maps increasingly shape planning, insurance, and household decisions, yet growing evidence shows that current mapping practice leads to decision outcomes that are not well aligned with underlying flood probabilities. Drawing together experimental and synthesis research, this presentation demonstrates that flood risk maps systematically elevate perceived risk, suppress housing demand, and generate socioeconomic effects that show limited sensitivity to actual flood likelihood. Experimental willingness-to-pay studies show that the presence of flood risk information reduces housing demand across all mapped zones, including very low risk areas, regardless of map framing. At the same time, synthesis evidence shows that technical language, colour choices, binary zoning, and limited treatment of uncertainty consistently weaken understanding, trust, and proportional response. These findings challenge the prevailing assumption that improving flood models alone improves decision making. We argue that flood risk maps function as behavioural interventions rather than purely informational products and, therefore, require careful reconsideration of how they are designed, tested, and governed. The presentation calls for mandatory behavioural testing of flood maps, clearer limits on map-led disclosure, and stronger integration with contextual, participatory, and non-map-based communication approaches. Without change, flood risk mapping will continue to transfer modelling uncertainty onto households, markets, and communities, with decision consequences that are unevenly distributed and potentially detrimental to long-term flood resilience.