Illustrating the impact of earthquakes: Evidence-based and user-centered recommendations on how to design earthquake scenarios and rapid impact assessments

Risk-based earthquake scenarios and rapid impact assessments can meaningfully improve how societies prepare for and deal with earthquakes. However, this is only the case when they are understood and perceived as useful to support mitigation and recovery actions. In this study, we are among the first to empirically assess how to best design earthquake scenarios and rapid impact assessment meeting the needs of different target audiences. We applied a transdisciplinary, iterative process involving a literature review, expert interviews, workshops with professional stakeholders, and internal reviews to design and improve the scenario and rapid impact assessment that were then tested in a representative survey with the Swiss public (N = 580). The results demonstrate a high perceived importance among all users groups for these products as well as advanced levels of comprehension. A focus was set on depicting uncertainties showing that the most simple visualization only using ranges was best understood and most liked. This supposes that the histograms predominantly used in existing outlets need to be reconsidered. Professional stakeholders and the public were further similarly challenged by more complex visualizations. The public survey further revealed the importance of the cartographic information as a supposedly relevant proxy to answer questions with a geographical reference and a requirement to improve the current version.