Building a better hazard map: collaborative, evidence-backed, user-optimised crisis hazard map design

Abstract

Volcanic hazard maps are used to share knowledge about the location of potentially dangerous volcanic processes with a wide range of audiences during a volcanic crisis. These maps comprise simplified representations of complex, overlapping, and uncertain geospatial phenomena that manifest on different spatial and temporal scales and with different metrics and intensities. Displaying this specialised information so that audiences with a range of volcanic and cartographic experience are empowered make informed decisions presents a number of challenges. While there are many possible approaches to representing hazard information on a map, there is little empirical evidence for how these approaches can influence audiences’ map-reading behaviour, inferences made about the information, and decisions made with the map in crisis situations.

Constructing meaning from a map is a complex information-processing exercise that requires cognitive processing of the visual appearance, patterns, and relationships of representative shapes and symbols on the map. Eye-movements and visual attention to elements of a display have been shown to reflect cognition and can give insight into how people draw inferences from graphics such as charts and maps. In this study, we use questionnaires and eye-gaze tracking to explore how 81 adults in the Taranaki region of New Zealand read and make decisions with volcanic hazard maps for a hypothetical eruption event for Mount Taranaki in order to better understand what people pay attention to on volcanic hazard maps in different decision-making contexts and how this is shaped by map design.

We find that top-down cognitive factors such as risk perception, experience, and cognitive loading shape visual attention to hazard map content and decisions made with the map under pressure and uncertainty. Additionally, we find that bottom-up factors in the way that hazard data is combined and displayed on the map can affect these cognitive factors. The findings suggest a complex interplay between top-down and bottom-up drivers of visual attention to volcanic hazard maps and empirically illustrate how cognitive processing of volcanic hazard maps may influence the behaviour of at-risk populations during a natural hazard crisis. Better characterising the role of these factors how they interplay can help us understand and mitigate communication challenges in times of crisis and uncertainty.