Mapping Health Vulnerability in Australia in the Context of Environmental Disasters

Australia faces increasing health pressures from climate-related disasters, particularly bushfires and floods, which interact with existing social and geographic inequities. Traditional health indexes rarely capture these environmental disruptions, limiting their ability to inform climate-resilient health policy. This study develops a holistic, multi-system health-environment index (HEI) tailored to the Australian context, integrating disaster exposure as a core environmental determinant. The aim was to evaluate how disaster-related vulnerability affects sustainable health outcomes across Local Government Areas (LGAs) nationwide. Three domains, health status, socioeconomic conditions, and environmental vulnerability were used to construct the index. The environmental domain was operationalised in three versions based on exposure to all disasters, bushfires, and floods, reflecting Australia’s major climate hazards. Domain indicators were extracted from the 2021 Australian Census via Table-Builder and combined using principal component analysis to produce three separate composite indexes. Welch’s t-tests compared index scores between disaster-exposed and unexposed LGAs. Spatial patterns were assessed using Local Indicators of Spatial Autocorrelation (LISA) to identify clusters of vulnerability. LGAs exposed to disasters showed significant lagged effects demonstrated significantly higher (poorer) health-environment index scores compared with unexposed LGAs across all index variations. Spatial analysis revealed clustering, with identifiable hotspots of poor health and environmental vulnerability across Australia. Findings suggest that disaster exposure is a substantial and spatially patterned contributor to poorer population health. This study provides the first Australia-wide, multi-system health-environment index that embeds disaster exposure as an indicator of environmental sustainability and climate vulnerability. By mapping hotspots where disaster risk and health disadvantage overlap, the index offers a practical tool for targeted resource allocation, climate-resilient planning, and equitable public health strategies.