Spatial Factors of Natural Hazard Risk Awareness and Preparedness in the Swiss Population
Creators: name: Basig, Leo
Publisher: name: ETH Zurich
Year: 2023

description: Natural hazards like floods, storms, rockfalls, hail, avalanches, and landslides pose significant risks in Switzerland. Due to climate change and land use increase, these risks are expected to grow further in the coming years. To cope with this situation, Switzerland is moving towards integrated risk management, requiring all societal levels to take responsibility, including the general population. For effective risk management, the general population has to be aware of and prepared for potential natural hazards. But is the risk judgment of the general population correct, and what are the factors of risk awareness and preparedness? To answer these questions, this thesis investigated if spatial factors, like the proximity to a hazard or natural hazard event records, influence the general population’s risk awareness and preparedness. Further, other factors of risk awareness and preparedness were explored. To achieve these goals, the answers of a nationwide survey conducted in 2021 with 1367 useable observations were combined with an environmental damage database and hazard maps. The combined data was then analyzed with Kruskal–Wallis tests, Spearman correlations, and regression models. The results showed that survey participants living in more severe hazard levels of the hazard maps do not perceive the threat to their property and health as higher than those living in less severe ones. The spatial factors: distance to the nearest substantial hazard zone, summed-up damage around the participants over long periods (15 years), difference in elevation from the closest larger water body, and slope at the address location were found to correlate significantly with the perceived likelihood of the corresponding natural hazard (flood, landslide or debris flow, rockfall, and avalanche) in the neighborhood. It was discovered that perceived threat, relevance of natural hazards, and intention to prepare all have the strongest correlations with summed-up recent (2-4 years) damage. Interestingly, infrastructure damage showed the strongest correlations with all awareness and preparedness variables. Additional awareness and preparedness factors identified in the regression models are: direct and indirect experience, information availability and impact, interest in being an active part of risk management, corona pandemic, and fear of natural hazards. To increase information availability and the impact that the information had on the risk attitude, information events, talks with experts, and www.naturgefahren.ch were found to be effective tools. These results suggest that the participants’ perceived threat does not match the factual risk, as many underestimate the threat to their property and health and do not prepare well enough. In contrast, the participants assessed the likelihood of events in their neighborhood much better, likely through the use of environmental cues. Making it seem that the likelihood evaluation is more rational than the threat judgment. Recommendations for risk communication are that hazard maps should be used to specifically inform people living in more severe hazard levels about the risks and how they can prepare. The window of opportunity after events should be used to turn increased awareness and preparation intentions into actions. Further, promoting www.naturgefahren.ch could be a cost-effective tool to communicate natural hazard risk and how to prepare for it.