Mapping applications based on Geographic Information Systems (GIS) have been increasingly valued by the hazard management community for their salient capabilities to process, analyse and visualise large volumes of spatial hazard and risk information. However, similar applications for the delivery of risk information to the public, especially in the face of an imminent disaster, are not prevalent and, when used, are often rudimentary in nature. Where attempts to integrate and visualise hazard/risk information through static maps or interactive web-mapping tools have been made, they have lacked a systematic consideration and evaluation of the tools’ effectiveness in satisfying users’ needs and achieving the intended communication goals.

This paper describes a user-centred framework utilised for designing a WebGIS-based bushfire early warning tool. WebGIS technology is employed to integrate the variety of spatial information and support map-based visualisation, and to allow for user interactions such as map manipulation and data selection. Based on a conceptualised bushfire-mapping tool, the questions concerning the design of the application are twofold: 1) What information should be communicated? And 2) how can maps be designed to effectively present the information? To address these questions, a range of hazard/risk information elements and associated cartographic representations were appraised for their effectiveness in respect to being understood, facilitating risk perception, and promoting risk-reducing behaviours by the end-users (i.e. the public). A two-phase assessment approach was conducted, involving an online survey to discern the most effective representation approach, and individual interviews to explore the effectiveness of each information element, presented using the user-identified effective means (e.g. image or text), for attaining the goals of public warnings. In addition to providing a user-centred knowledge base for developing a bushfire warning tool, the framework presented herein provides a general guide to user-centred design of map-mediated early warning for other hazards as well.