Management of city vulnerability to bushfire risk using advanced GIS-based spatial tools

Globally, cities are facing increased risk of more frequent and intense bushfires—also referred to as wildfires or forest fires—due to unprecedented heatwaves resulting from our changing climate. Australia has been considered one of the most fire-prone regions in the world, with harsher fire weather being expected to approach the continent in the near future. The 2019–20 Australian bushfire season, colloquially known as the Black Summer, was a period of unusually intense bushfires in many parts of Australia. In the Australian Capital Territory (ACT), the national capital city Canberra was blanketed by thick bushfire smoke on New Year's Day, and the ACT was declared a state of emergency as several bushfires threatened the city having already burned 60,000ha. There has been an extensive effort to introduce new policies aimed at reducing the risk of bushfire to built areas, adopting new standards defined under six bushfire attack level (BAL) ratings from low to extreme. This chapter reports the findings from a case study research project that aimed to determine the potential level of a property's bushfire risk in the Yarra Ranges, using an advanced GIS-based analysis tool. The case study findings were compared to the Canberra situation by performing spatial modeling and bushfire risk of properties that were determined by considering the closest vegetation type, distance, and slope ranges. Various what-if scenarios were conducted in the model including BAL assessments for each scenario. The approaches used in this study demonstrated that by the application of fine-scale and detailed spatial data, BAL determination within GIS-based analysis modeling can be performed with high accuracy to identify further critical infrastructure and emergency management response criteria for cities at risk.