ABSTRACT
Floods are a major threat in the UK. With floods becoming more frequent and severe, it is important that people are aware of the risk and informed of the actions they can take to prepare. Despite the efforts of both national and local information initiatives, evidence suggests that many people at risk fail to take preparatory action. Two types of visualizations are currently used in the UK to alert people of flood risk: river-level graphs visualize current or predicted river levels, and flood maps are used to communicate long-term flood risk. Both formats are powerful decision-making tools for technical audiences, but how effective are they for communicating with the public? This study explored people’s use of simplified flood maps and river-level graphs, to understand to what extent these two types of displays promote risk awareness and motivate action among lay users of risk visualizations. Results showed that while participants were more accurately extracting information from the graph, the map mobilized more intention action, particularly in participants at high risk. The different nature of both displays and the associated tasks are discussed in the context of flood awareness, as is the role of familiarity in the effectiveness of the displays.
