Comparison of tsunami evacuation map designs, warnings, and risk perceptions in Aotearoa New Zealand

Design of public-facing tsunami evacuation maps varies globally in terms of how evacuation zones are conceptualised and communicated. It is unclear how these design differences may affect individuals’ understanding and decision-making in response to warnings. Here, we use a survey to compare how three common evacuation map styles influence risk perceptions and intended protective actions in Aotearoa New Zealand (NZ) (n=1,128). We also explore relevant awareness of tsunami risk and warnings. Overall, we find that awareness of tsunami risk and evacuation zones is high, and there has been a substantial increase in the understanding that earthquakes can act as a natural warning for local-source tsunami over the last decade. Understanding the urgency of evacuation following natural warning signs, however, remains low among a quarter of participants. More people also expected an emergency mobile alert (EMA) to warn them of a local-source tsunami than an earthquake, indicating an awareness of modern warning systems in NZ, but a potential over-reliance on official warnings. Evacuation map design did not influence evacuation intentions, confidence in knowing actions to take, or perceptions of tsunami travel time and ability to get to safety. However, a single evacuation zone was associated with higher levels of concern than maps with multiple zones, which could encourage evacuation behaviour. Our findings suggest that the evacuation zone approach used on the map may not directly influence intended decision-making and comprehension among groups with high tsunami awareness, yet it can play an important role in threat perception, which may ultimately influence protective actions.