Social vulnerability in the context of bushfire risk at the urban-bush interface in Sydney: a case study of the Blue Mountains and Ku-ring-gai local council areas

In the recent past, Australia has experienced several catastrophic hazard events and the frequency and intensity of such events is expected to increase in the future. Natural hazards can rarely be fully prevented, yet their losses can be minimized if the necessary preparedness and mitigation actions are taken before an event occurs. Identification of vulnerable groups is an important first step in any preparedness and emergency management planning process. Social vulnerability refers to population characteristics that influence the capacity of a community to prepare for, respond to and recover from disasters. Factors that contribute to social vulnerability are often hidden and difficult to capture. This study analyzes the relative levels of social vulnerability of communities at the urban–bush interface in the Blue Mountains and Ku-ring-gai local council areas in New South Wales (NSW), Australia. We tested whether a standardized social vulnerability index could be developed using a pre-existing set of indicators. We created an exploratory principle component analysis model using Australian Bureau of Statistics 2006 census data at the Census Collection District (CCD) level. We identified variables contributing to social vulnerability and used the component scores to develop a social vulnerability index. Finally, the social vulnerability index was mapped at the CCD level. Our results indicate that both contributors to and the level of social vulnerability differ between and within communities. In other words, they are spatially variable. They show different spatial patterns across the areas, which provides useful information for identifying communities that are most likely to experience negative disaster impacts due to their socio-demographic characteristics.