Development and validation of a model for predicting fire behaviour in spinifex grasslands of arid Australia

2018 ◽  
Vol 27 (4) ◽  
pp. 271 ◽  
Author(s):  
Neil Burrows ◽  
Malcolm Gill ◽  
Jason Sharples
Keyword(s):  
Prescribed Burning ◽  
Weather Conditions ◽  
Fire Spread ◽  
Flame Height ◽  
Mitigation Measures ◽  
Fire Behaviour ◽  
Rate Of Spread ◽  
Wide Range ◽  
Wildfire Suppression ◽  
Fuel Moisture Content

Large wildfires are common in spinifex grasslands of arid Australia. Threat mitigation measures including fire preparedness, prescribed burning and wildfire suppression are greatly enhanced by the ability to predict fire behaviour. The new spinifex fire behaviour model presented here was developed and validated from 186 experimental fires across a wide range of fuel and weather conditions. Because spinifex fuels are discontinuous, modelling is a two-step process; once ignition is achieved, the first step is to determine the likelihood of fire spread, which is dependent on conditions of wind speed, fuel cover and fuel moisture content. If spread thresholds are met, the second step is to predict rate of spread and flame height using the same three independent variables. Thirty-six of the 186 experimental fires not used in modelling were used to validate the model, which proved to be reasonably accurate and an improvement on the previous model.

A generic, empirical-based model for predicting rate of fire spread in shrublands

2015 ◽  
Vol 24 (4) ◽  
pp. 443 ◽  
Author(s):  
Wendy R. Anderson ◽  
Miguel G. Cruz ◽  
Paulo M. Fernandes ◽  
Lachlan McCaw ◽  
Jose Antonio Vega ◽  
...  
Keyword(s):  
Moisture Content ◽  
Experimental Studies ◽  
Fire Spread ◽  
Fuel Moisture ◽  
Fire Behaviour ◽  
Weather Factors ◽  
Vegetation Height ◽  
Rate Of Spread ◽  
Wide Range ◽  
Fuel Moisture Content

A shrubland fire behaviour dataset was assembled using data from experimental studies in Australia, New Zealand, Europe and South Africa. The dataset covers a wide range of heathlands and shrubland species associations and vegetation structures. Three models for rate of spread are developed using 2-m wind speed, a wind reduction factor, elevated dead fuel moisture content and either vegetation height (with or without live fuel moisture content) or bulk density. The models are tested against independent data from prescribed fires and wildfires and found to predict fire spread rate within acceptable limits (mean absolute errors varying between 3.5 and 9.1 m min–1). A simple model to predict dead fuel moisture content is evaluated, and an ignition line length correction is proposed. Although the model can be expected to provide robust predictions of rate of spread in a broad range of shrublands, the effects of slope steepness and variation in fuel quantity and composition are yet to be quantified. The model does not predict threshold conditions for continuous fire spread, and future work should focus on identifying fuel and weather factors that control transitions in fire behaviour.

Got to burn to learn: the effect of fuel load on grassland fire behaviour and its management implications

2018 ◽  
Vol 27 (11) ◽  
pp. 727 ◽  
Author(s):  
Miguel G. Cruz ◽  
Andrew L. Sullivan ◽  
James S. Gould ◽  
Richard J. Hurley ◽  
Matt P. Plucinski
Keyword(s):  
Fire Spread ◽  
Flame Height ◽  
Fuel Load ◽  
Limiting Factor ◽  
Fire Behaviour ◽  
Load Effect ◽  
Fire Propagation ◽  
Rate Of Spread ◽  
Eastern Australia ◽  
Modelling Assumptions

The effect of grass fuel load on fire behaviour and fire danger has been a contentious issue for some time in Australia. Existing operational models have placed different emphases on the effect of fuel load on model outputs, which has created uncertainty in the operational assessment of fire potential and has led to end-user and public distrust of model outcomes. A field-based experimental burning program was conducted to quantify the effect of fuel load on headfire rate of spread and other fire behaviour characteristics in grasslands. A total of 58 experimental fires conducted at six sites across eastern Australia were analysed. We found an inverse relationship between fuel load and the rate of spread in grasslands, which is contrary to current, untested, modelling assumptions. This result is valid for grasslands where fuel load is not a limiting factor for fire propagation. We discuss the reasons for this effect and model it to produce a fuel load effect function that can be applied to operational grassfire spread models used in Australia. We also analyse the effect of fuel load on flame characteristics and develop a model for flame height as a function of rate of fire spread and fuel load.

Empirical modelling of surface fire behaviour in maritime pine stands

2009 ◽  
Vol 18 (6) ◽  
pp. 698 ◽  
Author(s):  
Paulo M. Fernandes ◽  
Hermínio S. Botelho ◽  
Francisco C. Rego ◽  
Carlos Loureiro
Keyword(s):  
Wind Speed ◽  
Moisture Content ◽  
Fire Spread ◽  
Fire Intensity ◽  
Fuel Moisture ◽  
Fire Behaviour ◽  
Spread Rate ◽  
Surface Fire ◽  
Rate Of Spread ◽  
Fuel Moisture Content

An experimental burning program took place in maritime pine (Pinus pinaster Ait.) stands in Portugal to increase the understanding of surface fire behaviour under mild weather. The spread rate and flame geometry of the forward and backward sections of a line-ignited fire front were measured in 94 plots 10–15 m wide. Measured head fire rate of spread, flame length and Byram’s fire intensity varied respectively in the intervals of 0.3–13.9 m min–1, 0.1–4.2 m and 30–3527 kW m–1. Fire behaviour was modelled through an empirical approach. Rate of forward fire spread was described as a function of surface wind speed, terrain slope, moisture content of fine dead surface fuel, and fuel height, while back fire spread rate was correlated with fuel moisture content and cover of understorey vegetation. Flame dimensions were related to Byram’s fire intensity but relationships with rate of spread and fine dead surface fuel load and moisture are preferred, particularly for the head fire. The equations are expected to be more reliable when wind speed and slope are less than 8 km h–1 and 15°, and when fuel moisture content is higher than 12%. The results offer a quantitative basis for prescribed fire management.

Grassfires

2008 ◽  
Author(s):  
Phil Cheney ◽  
Andrew Sullivan
Keyword(s):  
Diffusion Flames ◽  
Fire Suppression ◽  
Fire Spread ◽  
Personal Safety ◽  
Fire Behaviour ◽  
Ecological Processes ◽  
Rate Of Spread ◽  
Turbulent Diffusion Flames ◽  
Wildfire Suppression ◽  
The Impact

Grassfires: Fuel, Weather and Fire Behaviour presents information from CSIRO on the behaviour and spread of fires in grasslands. This second edition follows over 10 years of research aimed at improving the understanding of the fundamental processes involved in the behaviour of grassfires. The book covers all aspects of fire behaviour and spread in the major types of grasses in Australia. It examines the factors that affect fire behaviour in continuous grassy fuels; fire in spinifex fuels; the effect of weather and topography on fire spread; wildfire suppression strategies; and how to reconstruct grassfire spread after the fact. The three meters designed by CSIRO for the prediction of fire danger and rate of spread of grassfires are explained and their use and limitations discussed. This new edition expands the discussion of historical fires including Aboriginal burning practices, the chemistry of combustion, and the structure of turbulent diffusion flames. It also examines fire safety, including the difficulty of predicting wind strength and direction and the impact of threshold wind speed on safe fire suppression. Myths and fallacies about fire behaviour are explained in relation to their impact on personal safety and survival. Grassfires will be a valuable reference for rural fire brigade members, landholders, fire authorities, researchers and those studying landscape and ecological processes.

Field Guide: Fire in Dry Eucalypt Forest

2008 ◽  
Author(s):  
JS Gould ◽  
WL McCaw ◽  
NP Cheney ◽  
PF Ellis ◽  
S Matthews
Keyword(s):  
Fire Spread ◽  
Flame Height ◽  
Fire Behaviour ◽  
Effective Response ◽  
Understorey Vegetation ◽  
Near Surface ◽  
Field Guide ◽  
Eucalypt Forest ◽  
Rate Of Spread ◽  
Eucalypt Forests

An effective response to bushfires relies on accurate predictions of fire behaviour, particularly the rate of spread, intensity and ‘spotting’. This field guide has been developed to provide a systematic method for assessing fuel hazard and predicting potential fire behaviour in dry eucalypt forest. It will assist in making vital decisions that ensure the protection of fire crews and the community. This guide integrates Project Vesta research findings with the Victorian Overall Fuel Hazard Guide and is applicable to dry eucalypt forests throughout southern Australia. Fuel assessment is based on the hazard scoring system employed during Project Vesta which investigated the effects of fuel age and understorey vegetation structure on fire behaviour in these forests. Information provided in this guide can be used to: Define and identify different fuel layers and components of fuel structure and hazard; Determine the hazard score of surface and near-surface fuel layers and the height of the near-surface fuel for fire spread prediction; Determine elevated fuel height for flame height prediction; and determine surface fuel hazard score and bark hazard score for spotting distance prediction. The Field Guide provides tables to predict the potential rate of spread of a bushfire burning in dry eucalypt forest under summer conditions, and can also be used to predict flame height and maximum spotting distance. The guide also allows users to determine the moisture content of fine dead fuels throughout the day, and to account for the effect of slope on the rate of spread of a fire.

Fire Behaviour Modelling in Tasmanian Buttongrass Moorlands .II. Fire Behaviour

1995 ◽  
Vol 5 (4) ◽  
pp. 215 ◽  
Author(s):  
JB Marsden-Smedley ◽  
WR Catchpole
Keyword(s):  
Fire Management ◽  
Prediction Models ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
Fire Spread ◽  
Flame Height ◽  
Moderate Intensity ◽  
Fuel Moisture ◽  
Fire Behaviour ◽  
Fuel Moisture Content

An experimental burning program was carried out in Tasmanian buttongrass moorlands to develop fire behaviour prediction models for improving fire management. A range of previously developed prediction models were examined, but none provided adequate fire behaviour predictions. Empirical models were then developed to predict rate of fire spread and flame height in flat terrain, using the variables site age, dead fuel moisture content and surface wind speed. The models should provide good predictions for low to moderate intensity fires and adequate predictions for high intensity wildfires.

scholarly journals Dimensional analysis on forest fuel bed fire spread

2018 ◽  
Vol 48 (1) ◽  
pp. 105-110
Author(s):  
Jiann C. Yang
Keyword(s):  
Dimensional Analysis ◽  
Fire Spread ◽  
Fuel Particle ◽  
Wind Condition ◽  
Spread Rate ◽  
Fuel Loading ◽  
Rate Of Spread ◽  
Dimensionless Groups ◽  
Dimensionless Correlations ◽  
Fuel Moisture Content

A dimensional analysis was performed to correlate the fuel bed fire rate of spread data previously reported in the literature. Under wind condition, six pertinent dimensionless groups were identified, namely dimensionless fire spread rate, dimensionless fuel particle size, fuel moisture content, dimensionless fuel bed depth or dimensionless fuel loading density, dimensionless wind speed, and angle of inclination of fuel bed. Under no-wind condition, five similar dimensionless groups resulted. Given the uncertainties associated with some of the parameters used to estimate the dimensionless groups, the dimensionless correlations using the resulting dimensionless groups correlate the fire rates of spread reasonably well under wind and no-wind conditions.

scholarly journals Fire Behaviour Observation in Shrublands in Nova Scotia, Canada and Assessment of Aids to Operational Fire Behaviour Prediction

Fire ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 34
Author(s):  
Anne-Claude Pepin ◽  
Mike Wotton
Keyword(s):  
Nova Scotia ◽  
Moisture Content ◽  
Bulk Density ◽  
Prediction Models ◽  
Seasonal Effect ◽  
Fuel Type ◽  
Fire Behaviour ◽  
Fire Weather Index ◽  
Rate Of Spread ◽  
Wide Range

Parks Canada, in collaboration with Nova Scotia Lands and Forests and Natural Resources Canada, documented shrub fire behaviour in multiple plots burned over two periods: a spring period in June 2014 and a summer period in July 2017. The study area, located within Cape Breton Highlands National Park, comprised fifteen burn units (20 m by 20 m in size). Each unit was ignited by line ignition and burned under a wide range of conditions. Pre-burn fuel characteristics were measured across the site and used to estimate pre-fire fuel load and post-fire fuel consumption. This fuel complex was similar to many flammable shrub types around the world, results show that this shrub fuel type had high elevated fuel loads (3.17 ± 0.84 kg/m2) composed of exposed live and dead stunted black spruce as well as ericaceous shrubs, mainly Kalmia angustifolia (evergreen) and Rhodora canadensis (deciduous). Data show that the dead moisture content in this fuel complex is systematically lower than expected from the traditional relationship between FFMC and moisture content in the Canadian Fire Weather Index System but was statistically correlated with Equilibrium Moisture Content. A significant inverse relationship between bulk density and fire rate of spread was observed as well as a clear seasonal effect between the spring burns and the summer burns, which is likely attributable to the increase in bulk density in the summer. Unlike most shrub research, wind and dead moisture content did not have a statistically significant association with fire spread rates. However, we believe this to be due to noise in wind data and small dataset. Rate of spread as high as 14 m/min and flame lengths over 4 m were recorded under Initial Spread Index values of 6.4 and relative humidity of 54%. A comparison with a number of well-known shrubland spread rate prediction models was made. An aid to operational fire prediction behaviour is proposed, using a fuel type from the Canadian Fire Prediction System (O-1b) and a modified estimate of fuel moisture of the elevated fuel in the fuel complex.

A cellular automata model to link surface fires to firebrand lift-off and dispersal

2013 ◽  
Vol 22 (4) ◽  
pp. 428 ◽  
Author(s):  
Holly A. Perryman ◽  
Christopher J. Dugaw ◽  
J. Morgan Varner ◽  
Diane L. Johnson
Keyword(s):  
Wind Speed ◽  
Wildland Fire ◽  
Fire Spread ◽  
Fuel Moisture ◽  
Fuel Loading ◽  
Cellular Automata Model ◽  
Rate Of Spread ◽  
Lift Off ◽  
Fuel Moisture Content ◽  
Spot Fires

In spite of considerable effort to predict wildland fire behaviour, the effects of firebrand lift-off, the ignition of resulting spot fires and their effects on fire spread, remain poorly understood. We developed a cellular automata model integrating key mathematical models governing current fire spread models with a recently developed model that estimates firebrand landing patterns. Using our model we simulated a wildfire in an idealised Pinus ponderosa ecosystem. Varying values of wind speed, surface fuel loading, surface fuel moisture content and canopy base height, we investigated two scenarios: (i) the probability of a spot fire igniting beyond fuelbreaks of various widths and (ii) how spot fires directly affect the overall surface fire’s rate of spread. Results were averages across 2500 stochastic simulations. In both scenarios, canopy base height and surface fuel loading had a greater influence than wind speed and surface fuel moisture content. The expected rate of spread with spot fires occurring approached a constant value over time, which ranged between 6 and 931% higher than the predicted surface fire rate of spread. Incorporation of the role of spot fires in wildland fire spread should be an important thrust of future decision-support technologies.

Simulating the effectiveness of prescribed burning at altering wildfire behaviour in Tasmania, Australia

2018 ◽  
Vol 27 (1) ◽  
pp. 15 ◽  
Author(s):  
James M. Furlaud ◽  
Grant J. Williamson ◽  
David M. J. S. Bowman
Keyword(s):  
Prescribed Burning ◽  
Vegetation Type ◽  
Weather Conditions ◽  
Statistical Modelling ◽  
Fire Intensity ◽  
Fire Weather ◽  
Fire Behaviour ◽  
Large Area ◽  
Treatment Scenario ◽  
Wildfire Hazard

Prescribed burning is a widely accepted wildfire hazard reduction technique; however, knowledge of its effectiveness remains limited. To address this, we employ simulations of a widely used fire behaviour model across the ecologically diverse Australian island state of Tasmania. We simulate three broad scenarios: (1) no fuel treatment, (2) a maximal treatment, with the most possible prescribed burning within ecological constraints, and (3) 12 hypothetically more implementable state-wide prescribed-burning plans. In all simulations, we standardised fire-weather inputs to represent regionally typical dangerous fire-weather conditions. Statistical modelling showed that an unrealistically large maximal treatment scenario could reduce fire intensity in three flammable vegetation types, and reduce fire probability in almost every vegetation type. However, leverage analysis of the 12 more-realistic implementable plans indicated that such prescribed burning would have only a minimal effect, if any, on fire extent and that none of these prescribed-burning plans substantially reduced fire intensity. The study highlights that prescribed burning can theoretically mitigate wildfire, but that an unrealistically large area would need to be treated to affect fire behaviour across the island. Rather, optimisation of prescribed burning requires careful landscape design at the local scale. Such designs should be based on improved fire behaviour modelling, empirical measurement of fuels and analysis of actual wildfires.

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