Implementation of quantitative bushfire risk analysis in a GIS environment

Abstract

Bushfires pose a significant threat to lives and property. Fire management authorities aim to minimise this threat by employing risk-management procedures. This paper proposes a process of implementing, in a Geographic Information System environment, contemporary integrated approaches to bushfire risk analysis that incorporate the dynamic effects of bushfires. The system is illustrated with a case study combining ignition, fire behaviour and fire propagation models with climate, fuel, terrain, historical ignition and asset data from Hobart, Tasmania, and its surroundings. Many of the implementation issues involved with dynamic risk modelling are resolved, such as increasing processing efficiency and quantifying probabilities using historical data. A raster-based, risk-specific bushfire simulation system is created, using a new, efficient approach to model fire spread and a spatiotemporal algorithm to estimate spread probabilities. We define a method for modelling ignition probabilities using representative conditions in order to manage large fire weather datasets. Validation of the case study shows that the system can be used efficiently to produce a realistic output in order to assess the risk posed by bushfire. The model has the potential to be used as a reliable near-real-time tool for assisting fire management decision making.