HIGHFIRE RISK PROJECT

Project Team:
Rick McRae & Jason Sharples - University of New South Wales, Canberra, at the Australian Defence Force Academy.

The HighFire Risk Project

VORTICITY-DRIVEN LATERAL SPREAD EVENTS

This is an inventory of confirmed VLS events. Our research has shown for the first time how significant VLS can be in the development of catastrophic fires.

TERMINOLOGY

Vorticity-driven Lateral Spread (VLS) occurs when (1) wind blowing over a slope seperates at a rapid change in slope and (2) a lee-slope eddy wind forms in that seperation zone and (3) fire enters the eddy and (4) the eddy fills with smoke and embers and thermal expansion occurs within the eddy.
It comprises two components: (1) the local winds flow moves the fire cross-slope at right-angles to its main direction of spread (up to 5 km/hr has been observed), and (2) thermal expansion that arises from the fire inside the eddy air flow drives embers back into the prevailling winds overhead, resulting in dense spotfire formation for some distance downwind (up to 6 km has been observed). This then results in fire expansion in two directions, and leads to violent pyro-convection due to deep flaming.

Note: In the first dew years, VLS was termed fire channelling. Content is being updated to ensure consistency.
For more information read our papers on this subject - see below.


Fire trucks wait in the Brindabella Valley, NSW, on 18 January 2003, while the VLS on the left flank of the Broken Cart Fire draws near.
[Photo by a member of the Brindabella Volunteer Bushfire Brigade.]

EVENTS REGISTER

Click on the event code to get more detail, if it is available.
All events have been identified as VLS events through analyses of multispectral line-scan data or aerial photography. All events are in southeastern Australia or California.
DateFire LocationLongitude (d.dd°)Latitude (d.dd°)Elevation (m)Code
16 Dec 1977Lawson FireLawson, NSW150.43-33.71720771216A
9 Nov 2002Willow Vale FireMittagong, NSW150.46-34.43600021109A
6 Dec 2002 Baulkham Hills FireFiddletown, NSW 151.07 -33.60 200 021206A
8 Jan 2003McIntyres Hut FireBrindabella NP, NSW148.75-35.27800030108A
18 Jan 2003 McIntyres Hut FireFlea Creek, NSW148.73 -35.28 600 030118A
18 Jan 2003 McIntyres Hut FirePig Hill, NSW148.88 -35.23 1000 030118B
18 Jan 2003 McIntyres Hut FireDingo Dell, NSW148.84 -35.26 1000 030118C
18 Jan 2003 McIntyres Hut FireHyles Block South, ACT148.94 -35.26 500030118D
18 Jan 2003 McIntyres Hut FireGenges Trig, NSW148.85 -35.27 1100 030118E
18 Jan 2003 McIntyres Hut FireBlue Range, ACT148.86 -35.29 1100 030118F
18 Jan 2003 McIntyres Hut FireCotter Reserve, ACT148.95 -35.31 600 030118G
18 Jan 2003 Bendora FireBrindabella Road Lower, NSW148.76 -35.38 800 030118H
18 Jan 2003 Bendora FireBrindabella Road Upper, NSW148.78 -35.38 1000 030118I
18 Jan 2003 Bendora FireBendora Dam, ACT148.82 -35.45 900 030118J
18 Jan 2003 Broken Cart FireCooleman Creek, NSW148.70 -35.45900030118K
18 Jan 2003 Broken Cart FireBrowns Creek, NSW148.65 -35.46 900 030118L
18 Jan 2003 Broken Cart FireLog Hut Creek, NSW148.65 -35.52 1300 030118M
18 Jan 2003 Stockyard ComplexOrroral Valley, ACT148.99 -35.68 1100 030118N
26 Jan 2003 McIntyres Hut Fire“Kenya” property, NSW148.75 -35.16 1000 030126A
26 Jan 2003 Alpine ComplexBurrungubugge River, NSW148.48 -36.25 1700 030126B
26 Jan 2003 Alpine ComplexGuthega, NSW148.38 -36.37 600 030116C
26 Jan 2003 Alpine ComplexThredbo #1, NSW148.39 -36.45 1400 030126D
26 Jan 2003 Alpine ComplexThredbo #2, NSW148.43 -36.43 1500 030126D
26 Jan 2003 Alpine ComplexThredbo #3, NSW148.46 -36.41 1500030126D
26 Jan 2003 Alpine ComplexThredbo #4, NSW148.55 -36.38 1200 030126D
26 Jan 2003 Alpine ComplexDead Horse Gap, NSW148.35 -36.53 1700 030126H
26 Jan 2003 Alpine ComplexTom Groggin, NSW148.13 -36.59 900030126I
26 Oct 2006 Esperanza FireCalifornia 116.86 33.84 1200 061026A
7 Feb 2009East Kilmore FireKilmore Gap, Vic 145.02 -37.28 400 090207A
5 May 2009 Jesusita FireCalifornia 119.7 34.4 200 090505A
17 Dec 2009 Tea Tree Creek FireMichelago, NSW149.2-35.7800 091217A

READING

McRae, R.H.D. (2004)
The Breath of the Dragon - Observations of the January 2003 Bushfires.
Proceedings, 2004 Australian Bushfire Research Conference. 		View PDF paper
View PDF presentation
McRae, R.H.D., Weber, R.O. & Sharples, J.J. (2006).
Lessons learnt from the Jan 03 fires
Proceedings 2006 Bushfire Research Conference. 		View PDF paper
View PDF presentation
Sharples, JJ. (2009).
An overview of mountain meteorological effects relevant to fire behaviour and bushfire risk.
International Journal of Wildland Fire 18(7): 737-754. 		View PDF paper
McRae, R.H.D., Sharples, J.J. & Weber, R.O. (2007).
Are big fires inevitable?
Proceedings, Australasian Fire Authorities Council 2007 Conference. 		View PDF paper
View PDF presentation
Sharples, J.J., Weber, R.O. & McRae, R.H.D. (2007).
Wind-Terrain Effects on Rugged LandscapeFire: Lee-slope Channelling
Poster presented at 2007 AFAC/Bushfire CRC Conference. 		View PDF poster
Sharples, J.J., McRae, R.H.D. & Wilkes, S.R. (2012).
Wind-terrain effects on the propagation of large wildfires in rugged terrain: fire channelling.
International Journal of Wildland fire doi:10.1071/WF10055 		CSIRO Publishing.
15 July 2024