Developing an impact index for the Australian Fire Danger Rating System: predicting potential structure loss from wildfires

Dan Krix; James Monks; Stuart Matthews; Meaghan Jenkins; Alex Holmes; Sam Sauvage; John W. Runcie

doi:10.1071/WF24148

RESEARCH ARTICLE (Open Access)

Next Contents Vol 34(9)

Developing an impact index for the Australian Fire Danger Rating System: predicting potential structure loss from wildfires

Dan Krix

^A , James Monks ^A , Stuart Matthews ^C , Meaghan Jenkins ^A ^B ^* , Alex Holmes ^A , Sam Sauvage ^D and John W. Runcie ^A

+ Author Affiliations

- Author Affiliations

^A New South Wales Rural Fire Service, 4 Murray Rose Avenue, Sydney Olympic Park, NSW 2127, Australia.

^B Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia.

^C NovaSystems, Level 3/100 William Street, Sydney, NSW 2000, Australia.

^D Bureau of Meteorology, 111 Macquarie Street, Hobart, Tas 7001, Australia.

^* Correspondence to: m.jenkins@westernsydney.edu.au

International Journal of Wildland Fire 34, WF24148 https://doi.org/10.1071/WF24148

Submitted: 10 September 2024 Accepted: 21 July 2025 Published: 22 August 2025

© 2025 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of IAWF. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Background

Accurately predicting impacts of wildfires remains a top priority for fire and land management agencies. The Australian Fire Danger Rating System (AFDRS) redesigned forecasts of fire danger for Australian fire agencies, modernising the fire danger system. The next phase of the AFDRS focuses on developing indices for Fire Ignition, Suppression and Impact (FISI).

Aims

Impact models were developed to predict structure loss at the bushland–urban interface in eastern Australia.

Methods

Structure counts, cleared land and canopy height, calculated at radii 50–1000 m from structures, as well as terrain ruggedness, were used to model individual structure loss during wildfire and proportional loss in built-up areas.

Key results

The individual and proportional structure loss models accurately predicted structure loss (individual losses: true positive rate (TPR) = 0.67, true negative rate (TNR) = 0.69; proportional loss r² = 0.71). Loss was lowest where structures had defensible space on flat ground, with higher numbers of structures nearby and shorter vegetation canopy height.

Conclusions

The models determine the probability of structure loss during destructive wildfire.

Implications

These models provide fire agencies information on the likelihood of structure loss and aid in decision-making. The impact index may support effective resource allocation, potentially reducing structure loss.

Keywords: AFDRS, fire danger rating, forecast, impact, model, probability, structure loss, wildfire.

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