NBIC-ACS Stage 2 Fireline Intensity Potential - baseline and projected scenarios, 20% and 10% annual exceedance probabilities

Fireline intensity, expressed in kilowatts per metre (kW/m), quantifies the energy released along the leading edge (or head fire front) of a bushfire and is a key indicator of a fire’s behaviour and intensity. Fireline intensity calculations are dependent on type and condition of vegetation (often referred to as fuel), weather conditions and terrain. Empirical fire behaviour models describe the complex, non-linear relationships between those parameters, and are used to calculate fire intensity for different vegetation types. Evaluating those fire behaviour models at continental scale is a significant challenge, and therefore, a comprehensive, spatially explicit assessment of fireline intensity across Australia under current and future climate conditions has been so far lacking. Here we provide predicted upper-bound fireline intensity values based on plausible worst-case scenarios across the Australian landscape, defined for a set of annual exceedance probabilities. We calculate fireline intensity based on the 8 head fire rate of spread models used by the Australian Fire Danger Rating System, applied to 90m resolution fuel classification data and over 43 years of hourly weather timeseries. Fuel input parameters are derived from a variety of scientific principles and data sources, including satellite remote sensing timeseries of at least 500m resolution. Weather parameters are defined based on historical or projected conditions to 2090, resulting in one baseline scenario derived from historical reanalysis data, plus 18 projected scenarios derived from the latest climate modelling data. Terrain parameters are derived from a 30m resolution based on smoothed Digital Elevation Model. Fireline intensity is a direct way to define bushfire hazard, higher fireline intensity means higher destructive potential from radiant heat, flames, embers and convective plume. Its applicability spans across climate adaptation, emergency planning, health and ecosystem resilience across Australia. This dataset marks a significant advancement in the quality of bushfire hazard assessment, surpassing previous efforts and providing a robust foundation for informed decision-making in managing and mitigating Australia’s escalating bushfire risks under a changing climate.