Research leader

A/Prof Jason Sharples
A/Prof Jason Sharples Research Leader

Research team

Dr Andrew Sullivan
Dr Andrew Sullivan Research Team
Dr James Hilton
Dr James Hilton Research Team
Dr Will Swedosh Research Team
Chris Thomas Research Team
Richard Hurley Research Team

End User representatives

Brad Davies End-User
Andrew Stark
Andrew Stark End-User
Laurence McCoy End-User
Dr Neil Burrows
Dr Neil Burrows End-User
Mark Chladil
Mark Chladil End-User

Student researchers

Michael Storey Student Reseachers

Fire behaviour in dry eucalypt forests in Australia is characterised by the occurrence of spotfires—new fires ignited by the transport of embers ahead of an existing fire. Under most burning conditions, spotfires play little role in the overall propagation of a fire, except where spread is impeded by breaks in fuel or topography. Spotfires allow these impediments to be overcome.

However, under conditions of severe bushfire behaviour, spotfire occurrence can be so prevalent that spotting becomes the dominant propagation mechanism and the fire spreads as a cascade of spotfires forming a ‘pseudo’ front.

It has long been recognised that the presence of multiple individual fires affects the behaviour and spread of all fires present. The converging of separate individual fires into larger fires is called coalescence and can lead to rapid increases in fire intensity and spread rate, leading to the phenomenon of a ‘fire storm’. This coalescence effect is frequently used in prescribed burning, with multiple point ignitions used to rapidly burn out large areas.

This project is focusing on:

  • Fire coalescence to provide better predictions of fire propagation
  • The intrinsic dynamics of flame front propagation as a contributor to fire spread across different spatial and temporal scales
  • Within a simulation framework an end-to-end model of the behaviour of mass spotfires, from firebrand/ember launch to fire coalescence.

The modelling and simulation aspects of the project have contributed to understanding the processes that drive fire coalescence and dynamic fire spread. In particular, the research has addressed the role that fire-line geometry (especially curvature) plays in the dynamic propagation of bushfires.

The team has demonstrated the performance advantages of fire propagation models incorporating curvature dependence when applied to simple wind-driven fires at both laboratory and field scales. The research has also produced fundamental insights into how the shape of the fire line affects the dynamic behaviour of the fire as a whole. Coupled fire-atmosphere modelling was used to investigate how fire-induced air movements (pyroconvection) can produce significantly enhanced rates of spread for certain fire shapes.

Utilising the research outcomes will include development of education and training materials relating to dynamic fire behaviour and extreme fire development, which will incorporate the research findings on fire coalescence and mass spotfires.

Research findings will also be used to develop metrics of relevance to the National Fire Danger Rating Project. In particular, existing measures of ‘convective fire power’ based solely on information relating to the fire perimeter will be extended to include contributions from within flaming zones where spot fire coalescence can contribute significantly to pyroconvective release.

Year Type Citation
2018 Conference Paper Bates, J. Research proceedings from the 2018 Bushfire and Natural Hazards CRC and AFAC Conference. Bushfire and Natural Hazards CRC & AFAC annual conference 2017 (Bushfire and Natural Hazards CRC, 2018).
2018 Conference Paper Hilton, J. et al. Pyroconvective interactions and dynamic fire propagation. AFAC18 (2018).
2018 Journal Article Raposo, J. R. et al. Analysis of the physical processes associated with junction fires at laboratory and field scales. International Journal of Wildland Fire 27, (2018).
2018 Journal Article Lahaye, S. et al. How do weather and terrain contribute to firefighter entrapments in Australia?. International Journal of Wildland Fire 27, 85-98 (2018).
2018 Journal Article Lahaye, S. et al. What are the drivers of dangerous fires in Mediterranean France?. International Journal of Wildland Fire 27, 155-163 (2018).
2018 Journal Article Hilton, J., Sullivan, A., Swedosh, W., Sharples, J. J. & Thomas, C. Incorporating convective feedback in wildfire simulations using pyrogenic potential. Environmental Modelling & Software 107, 12-24 (2018).
2017 Conference Paper Sharples, J. J. A unified approach to fire spread modelling. AFAC17 (Bushfire and Natural Hazards CRC, 2017).
2017 Conference Paper Lahave, S., Sharples, J. J., Matthews, S., Heemstra, S. & Price, O. F. What are the safety implications of dynamic fire behaviours?. 22nd International Congress on Modelling and Simulation (2017).
2017 Conference Paper Rumsewicz, M. Research proceedings from the 2017 Bushfire and Natural Hazards CRC and AFAC Conference. Bushfire and Natural Hazards CRC & AFAC annual conference 2017 (Bushfire and Natural Hazards CRC, 2017).
2017 Report Sharples, J. J., Hilton, J. & Sullivan, A. Fire coalescence and mass spotfire dynamics - experimentation, modelling and simulation: annual project report 2016-17. (Bushfire and Natural Hazards CRC, 2017).
2016 Journal Article Sharples, J. J. et al. Natural hazards in Australia: extreme bushfire. Climatic Change 139, 85-99 (2016).
2016 Journal Article Hilton, J., Sharples, J. J. & Sullivan, A. Curvature effects in the dynamic propagation of wildfires. International Journal of Wildland Fire 25, (2016).
2016 Report Sharples, J. J., Hilton, J. & Sullivan, A. Fire coalescence and mass spot fire dynamics: experimentation, modelling and simulation: Annual project report 2015-2016. (Bushfire and Natural Hazards CRC, 2016).
2015 Presentation Sharples, J. J., Hilton, J. & Sullivan, A. Dynamic modelling of fire coalescence. (2015).
2015 Report Sharples, J. J. Fire coalescence and mass spotfire dynamics: Experimentation, modelling and simulation - Annual project report 2014-2015. (Bushfire and Natural Hazards CRC, 2015).
Nature Abhors Curvature - Fires Included! Modelling Spot Fire Coalescence
18 Aug 2015
Spotting can be the dominant fire propagation mechanism during times of extreme fire weather. Spot fires can...
James Hilton Conference Poster 2016
14 Aug 2016
Predictive models of natural hazards have become a necessity for emergency management, mitigation and...
Experimental investigation of junction fire dynamics, with and without wind
29 Jun 2017
Junction fires occur when two oblique fire lines intersect with one another. The interaction of the two fire...
Incorporation of spotting and fire dynamics in a coupled atmosphere - fire modelling framework
19 Sep 2018
Spotting is a challenging aspect of bushfire operations. We currently have poor capacity to estimate exactly...