Is a picture worth a thousand words? Evaluating the effectiveness of maps for delivering wildfire warning information

Maps are a sensible approach for communicating wildfire early warnings to the public as such warnings often contain a multitude of spatial information. However, a reluctance of agencies was found in using accurate and timely wildfire maps for public warnings, a sentiment potentially fuelled by beliefs that the public are not fluent map-readers and may be overwhelmed by the large amount of information. To test the validity of these beliefs, this study empirically compared the effectiveness of maps versus traditional text-based approaches for communicating spatial-related wildfire warning information. Through an online survey, 261 residents from wildfire prone areas in Western Australia were asked to view multidimensional spatial information regarding a simulated wildfire scenario presented as either text messages or maps, and were subsequently queried for their comprehension, their risk perceptions, and the attractiveness of the presentation format. Additionally, the survey captured the time required to interpret the varied information representations. The results showed that appropriately designed maps prevailed over text messages for the communication of most wildfire warning information by improving comprehension, elevating risk perceptions, and increasing appeal to the public. However, an optimal communication approach would be to couple map designs with several imperative textual descriptors. Especially, the textual description of safe shelters in the community (i.e. location names and addresses) yielded indispensible meaning when the locations were well-known landmarks, and hence should not be replaced by map-based depiction. Furthermore, several heuristics were identified to facilitate the design of effective warning maps across hazards in general.