How does multi-hazard communication influence risk perception, attitudes, and behaviour: an experimental survey

Our understanding of the effects of multi-hazard contexts on risk perception and behaviour is limited. In a novel approach, we utilise an experimental survey where groups of participants are asked to consider a different combination of the same two hazards: an earthquake and a tsunami. We discovered that asking people about one hazard has significant and meaningful effects on their judgements of the second hazard. In particular, participants perceived significantly less threat from a tsunami after thinking about an earthquake, and vice versa. Intention to prepare for a tsunami was also lower if the participants had already been asked about an earthquake; however, intention to prepare for an earthquake was higher if participants had already been asked about a tsunami. These findings have important implications for public education efforts, suggesting that it may be better to focus on encouraging preparation for a single hazard or for impacts separate from a specific causal hazard, rather than overloading the public with multiple risks simultaneously.