Fire Danger Indices used in Amicus
In Australia, two systems for calculating fire danger (as a numerical index and as a categorised rating) are used, one for grasslands and one for forests the two predominant vegetation types.
Grassland Fire Danger Index
Calculated using the McArthur Mk 4 Grassland Fire Danger Meter which was developed as a circular slide rule by Alan McArthur in the 1960s and published by the Forestry and Timber Bureau which in 1975 became the CSIRO Division of Forestry.
McArthur AG (1966) ‘Weather and grassland fire behaviour.’ Forestry and Timber Bureau Leaflet 100, Department of Natural Development, Canberra, ACT.
Forest Fire Danger Index
Calculated using the McArthur Mk 5 Forest Fire Danger Meter. This was also developed by Alan McArthur, published by the Forestry and Timber Bureau.
McArthur AG (1967) ‘Fire behaviour in eucalypt forests.’ Forestry and Timber Bureau Leaflet 107, Department of Natural Development,Canberra, ACT.
Both of these meters were converted to equations by Noble, Bary and Gill (1980) and are employed here. The Mk 4 Grassland Fire Danger Meter and the Mk 5 Forest Fire Danger Meter were metricated versions of the previous versions which appeared in the publications by McArthur listed above.
Noble IR, Bary GAV, Gill AM (1980) McArthur’s fire danger meters expressed as equations. Australian Journal of Ecology 5, 201-203.
Fire Behaviour Models used in Amicus
Amicus employs a number of fire behaviour models that have been developed by researchers from a range of organisations over the years. It is now more than 60 years since Alan McArthur became Australia’s first full time bushfire behaviour researcher. In that time, many systems have been developed for predicting the potential behaviour of bushfires in a wide variety of vegetation and fuel types. Amicus follows the analysis of the performance of these models by CSIRO (see Cruz et al 2015 in the Publications menu and the book A Guide to Rate of Spread Models for Australian Vegetation on the Home page) and provides those models recommended for particular fuel types. A brief description of and original reference for each recommended model is given below, organised by fuel types.
Fuel types = “Continuous open”, “Woodlands” and “Open forest”.
These equations are used for fires in continuous open grasslands and woodlands and open forest with grassy understoreys. They were developed by CSIRO and were published in Cheney et al. (1998), with a more descriptive explanation of their application given in the Grassfires book (Cheney and Sullivan 2008) and Sullivan (2010).
Cheney NP, Gould JS, Catchpole WR (1998) Prediction of fire spread in grasslands. International Journal of Wildland Fire 8, 1-13.
Cheney P, Sullivan A (2008) ‘Grassfires, fuel, weather and fire behaviour.’ (CSIRO Publishing: Collingwood).
Sullivan, AL (2010) Grassland fire management in future climate. Advances in Agronomy, 106, 173-208.
Fuel type = “Spinifex”
This model was developed from two large sets of experimental fires conducted by Neil Burrows and colleagues from the Western Australian Department of Environment and Conservation (now known as the Department of Parks and Wildlife, was formerly Department of Conservation and Land Management). The paper was published in the Proceedings of the Royal Society of Queensland, after originally being presented at the Bushfire 2006 conference. It replaced an earlier version of the model published in 1990. A replacement model containing data from another series of experiments is expected soon.
Burrows ND, Ward B, Robinson A (2009) Fuel dynamics and fire spread in spinifex grasslands of the Western Desert. In ‘Proceedings of the Royal Society of Queensland’ pp. 69-76. (Royal Society of Queensland Inc.: St Lucia Australia).
Native forest vegetation
Fuel type = “Dry Eucalypt”, Condition = “Wildfire”
This model is based on a large set of experimental fires conducted under dry summer conditions by CSIRO and the Western Australian Department of Parks and Wildlife and validated against a large set of wildfire observations. It was published in the journal Forest Ecology and Management:
Cheney NP, Gould JS, McCaw WL, Anderson WR (2012) Predicting fire behaviour in dry eucalypt forest in southern Australia. Forest Ecology and Management 280, 120-131.
Other papers associated with this model include:
Gould, J. S.; McCaw, W. L. & Cheney, N. P. 2011. Quantifying fine fuel dynamics and structure in dry eucalypt forest (Eucalyptus marginata) in Western Australia for fire management. Forest Ecology and Management, 262, 531-546.
McCaw, L. W.; Gould, J. S.; Cheney, N. P.; Ellis, P. F. & Anderson, W. R. 2012. Changes in behaviour of fire in dry eucalypt forest as fuel increases with age. Forest Ecology and Management, 271, 170-181.
Wotton, B. M.; Gould, J. S.; McCaw, W. L.; Cheney, N. P. & Taylor, S. W. 2011. Flame temperature and residence time of fires in dry eucalypt forest. International Journal of Wildland Fire, 21, 270-281.
Fuel type = “Wet Eucalypt”, Condition = “Wildfire”
This model is the same as the previous except that it uses wind speed correction factors (i.e. three coefficients that modify the wind speed in the open to that under the canopy) taken from the Forest Fire Behaviour Tables for Western Australia developed and published by the Western Australian Department of Conservation and Land Management.
Sneeuwjagt RJ, Peet GB (1985) ‘Forest fire behaviour tables for Western Australia.’ (WA Department of Conservation and Land Management: Perth)
Fuel type = “Dry Eucalypt”, Condition = “Prescribed fire”
This model is Alan McArthur’s Controlled Burning Guide for Eucalypt forests. The equations for the guide were developed by Jim Gould (CSIRO) and published in Australian Forestry.
McArthur AG (1962) ‘Control burning in eucalypt forests.’ Commonwealth of Australia Forestry and Timber Bureau, Number 80, Canberra, ACT.
Gould JS (1994) Evaluation of McArthur’s’ control burning guide in regrowth Eucalyptus sieberi. Australian Forestry 57, 86-93.
Fuel type = “Wet Eucalypt”, Condition = “Prescribed fire”
This model is the Forest Fire Behaviour Tables for Western Australia (Sneeuwjagt and Peet 1985, see above), which were converted to equations by Judi Beck
Beck JA (1995) Equations for the forest fire behaviour tables for Western Australia. CALMScience 1, 325-348.
Fuel type = “Temperate shrubland”
This model was developed from a combined dataset from a range of different locations and conditions from a large set of authors.
Anderson W, Cruz M, Fernandes PM, McCaw WL, Antonio Vega J, Bradstock RA, Fogarty L, Gould JS, McCarthy GJ, Marsden-Smedley JB, Matthews S, Mattingley G, Pearce HG, van Wilgen B (2015) A generic, empirical-based model for predicting rate of fire spread in shrublands. International Journal of Wildland Fire, in press.
Fuel type = “Buttongrass”
This model was developed by Jon Marsden-Smedley (University of Tasmania) and Wendy Anderson (formerly Catchpole, University of NSW). This fuel type is mainly only present in western Tasmania.
Marsden-Smedley JB, Catchpole WR (1995) Fire modelling in Tasmanian buttongrass moorlands II. Fire behaviour. International Journal of Wildland Fire 5, 215-228.
Fuel type = “Semi –arid heath”
Cruz MG, Matthews S, Gould J, Ellis P, Henderson M, Knight I, Watters J (2010) ‘Fire dynamics in mallee-heath; fuel weather and fire behaviour prediction in South Australian semi-arid shrublands.’ Bushfire Cooperative Research Centre Technical Report A.10.01, East Melbourne, Victoria.
Fuel type = “Semi –arid mallee-heath”
Cruz MG, McCaw WL, Anderson WR, Gould JS (2013) Fire behaviour modelling in semi-arid mallee-heath shrublands of southern Australia. Environmental Modelling & Software 40, 21-34.
Fuel type = “pine”
Cruz MG, Alexander ME, Fernandes PAM (2008) Development of a model system to predict wildfire behaviour in pine plantations. Australian Forestry 71, 113-121.
Fuel type = “blue gum”
There are no formal models specifically for fire spread in blue gum plantations. Instead, the fire spread model to be employed depends on the age and productivity of the plantation. If the plantation is relatively young and the ground cover is dominated by grass then the grassland fire spread model of Cheney et al. (1998) is used (with a user-defined wind correction factor). . If the plantation is more well established with dominate litter ground cover then the model for wildfires in dry eucalypt forests (Cheney et al. 2012) will be used.
Other models used in Amicus
For correction factors for fire spread on slopes, Amicus employs the McArthur rule of thumb of doubling the flat ground rate of spread for every ten degrees on positive slopes. For fire spread on negative slopes, Amicus uses the slope correction factor model kataburn developed by Sullivan et al. (2014). Slope is calculated as that sensed in the direction of the wind.
Sullivan AL, Sharples JJ, Matthews S. and Plucinski MP (2014) A downslope fire spread correction factor based on landscape-scale fire behaviour. Environmental Modelling & Software 62, 153-163.