Interactive web based volcanic hazard maps: Campi Flegrei caldera Italy.

Maps used to communicate hazards such as severe weather and wildfires are increasingly being presented online to be interactive and dynamic for users. Volcanic hazard maps are beginning to follow this trend and have been reproduced as interactive web maps following the eruptions of Agung in 2017, and Kilauea and Fuego in 2018. The progression to using web maps represents a significant change in how volcanic hazards and emergencies are presented. However, limited research has investigated how this format can be best used for hazard communication at volcanoes, which is why research was undertaken to investigate the usefulness and challenges of using web maps for volcanic hazard communication.

As an example of how they can be useful, a new series of user-centered web maps for Campi Flegrei caldera, Southern Italy, were generated. The preferences of 250 survey respondents and a review of twenty interactive maps from a wide variety of disciplines helped tailor the web maps to the needs of three user groups: local residents, emergency managers and businesses. In this approach, unrest and eruption scenarios were presented as well as crisis and background hazard data. The maps allowed users to select the information important to them and highlighted the methodological constraints and useful attributes of interactive hazard mapping.

Results showed that interactive maps are a useful tool for hazard communication and should be considered for use alongside traditional hazard maps. During evolving emergencies this format can be used to convey hazards, uncertainty and evacuation information, all of which would be difficult to convey on a single static map. Having in place an established and tested web-based map would provide a quick and simple basis for emergency communication should an volcanic emergency arise. However, challenges exist in how to design maps that cater for different audiences and at the same time effectively communicate all necessary information.