@article {bnh-8367, title = {Simulated behaviour of wildland fire spreading through idealised heterogeneous fuels}, journal = {International Journal of Wildland Fire}, year = {2023}, month = {02/2023}, abstract = {

Homogeneous vegetation is widely used in wildland fire behaviour models, although real vegetation is heterogeneous in nature and composed of different kinds of fuels and non-combustible parts. Many features of fires can arise from this heterogeneity. For land management and firefighting, creating heterogeneous fuel areas may be useful to reduce fire intensity and rate of spread (ROS), and alter fire geometry. Recently, an empirical model for fire spread in spinifex grasslands was developed and validated against experimental measurements. In this study, physics-based grassland fire behaviour simulations were conducted with varying percentages of fuel cover and alternating square and rectangular patches of burnable and non-burnable material. The environmental conditions and thermophysical properties of the grassland were kept constant throughout the simulation to separate the effects of fuel heterogeneities from other parameters. For three sets of nominal wind velocities, 3, 5.6 and 10 m s-1, we identified {\textquoteleft}go{\textquoteright} and {\textquoteleft}no go{\textquoteright} fires. Reasonable agreement between the non-dimensionalised simulated ROS and observed ROS in spinifex was found. There is a significant reduction of fire intensity, ROS, flame length, fire width and fire line length due to the heterogeneous effect of vegetation.

}, keywords = {fire line length, flame length, heterogeneity, homogeneous vegetation, Rate of spread, spinifex, wildland fire, wind spee}, doi = {https://doi.org/10.1071/WF22009}, url = {https://www.publish.csiro.au/wf/WF22009}, author = {Nazmul Khan and Duncan Sutherland and Khalid Moinuddin} } @article {bnh-8376, title = {Determining firebrand generation rate using physics-based modelling from experimental studies through inverse analysis}, journal = {Fire}, volume = {5}, year = {2022}, month = {01/2022}, abstract = {

Firebrand spotting is a potential threat to people and infrastructure, which is difficult to predict and becomes more significant when the size of a fire and intensity increases. To conduct realistic physics-based modeling with firebrand transport, the firebrand generation data such as numbers, size, and shape of the firebrands are needed. Broadly, the firebrand generation depends on atmospheric conditions, wind velocity and vegetation species. However, there is no experimental study that has considered all these factors although they are available separately in some experimental studies. Moreover, the experimental studies have firebrand collection data, not generation data. In this study, we have conducted a series of physics-based simulations on a trial-and-error basis to reproduce the experimental collection data, which is called an inverse analysis. Once the generation data was determined from the simulation, we applied the interpolation technique to calibrate the effects of wind velocity, relative humidity, and vegetation species. First, we simulated Douglas-fir (Pseudotsuga menziesii) tree-burning and quantified firebrand generation against the tree burning experiment conducted at the National Institute of Standards and Technology (NIST). Then, we applied the same technique to a prescribed forest fire experiment conducted in the Pinelands National Reserve (PNR) of New Jersey, the USA. The simulations were conducted with the experimental data of fuel load, humidity, temperature, and wind velocity to ensure that the field conditions are replicated in the experiments. The firebrand generation rate was found to be 3.22 pcs/MW/s (pcs-number of firebrands pieces) from the single tree burning and 4.18 pcs/MW/s in the forest fire model. This finding was complemented with the effects of wind, vegetation type, and fuel moisture content to quantify the firebrand generation rate.

}, keywords = {FDS, Firebrands, physics-based modeling, wildland fire, Wildland-urban interface}, doi = {https://doi.org/10.3390/fire5010006}, url = {https://www.mdpi.com/2571-6255/5/1/6}, author = {Amila Wickramasinghe and Nazmul Khan and Khalid Moinuddin} } @article {bnh-6392, title = {Evolution of an extreme Pyrocumulonimbus-driven wildfire event in Tasmania, Australia}, journal = {Natural Hazards and Earth System Sciences}, year = {2019}, month = {12/2019}, abstract = {

Extreme fires have substantial adverse effects on society and natural ecosystems. Such events can be associated with intense coupling of fire behaviour with the atmosphere, resulting in extreme fire characteristics such as pyrocumulonimbuscloud (pyroCb) development. Concern that anthropogenic climate change is increasing the occurrence of pyroCbs globally is driving more focused research into these meteorological phenomena. Using 6-minute scans from a nearby weather radar, we describe the development of a pyroCb during the afternoon of 4 January 2013 above the Forcett-Dunalley fire in south-eastern Tasmania. We relate storm development to: (1) near-surface weather using the McArthur Forest Fire Danger Index (FFDI), and the C-Haines Index, a measure of the vertical atmospheric stability and dryness both derived from gridded weather reanalysis for Tasmania (BARRA-TA), and (2) a chronosequence of fire severity derived from remote sensing. We show that the pyroCb rapidly developed over a 24-minute period in the afternoon of 4 January, with the cloud top reaching a height of 15 km. The pyroCb was associated with a highly unstable atmosphere (C-Haines 10-11) and Severe-marginally Extreme (FFDI 60-75) near-surface fire weather, and formed over an area of forest that was severely burned (total crown defoliation). We use spatial patterns of elevated fire weather in Tasmania, and fire weather during major runs of large wildfires in Tasmania for the period 2007-2016 to geographically and historically contextualise this pyroCb event. Although the Forcett-Dunalley fire is the only known record of a pyroCb in Tasmania, our results show that eastern and south-eastern Tasmania are prone to the conjunction of high FFDI and C-Haines values that have been associated with pyroCb development. Our findings have implications for fire weather forecasting and wildfire management, and highlight the vulnerability of southeast Tasmania to extreme fire events.

}, keywords = {C-Haines, extreme fire, fire severity, Fire weather, McArthur Forest Fire Danger Index, pyrocumulonimbus, smoke plume injection, Tasmania, wildland fire}, doi = {https://doi.org/10.5194/nhess-2019-354}, url = {https://www.nat-hazards-earth-syst-sci-discuss.net/nhess-2019-354/}, author = {Mercy Ndalila and Grant Williamson and Paul Fox-Hughes and Jason J. Sharples and David Bowman} } @article {bnh-6856, title = {Quantification of inter-regional differences in risk mitigation from prescribed burning across multiple management values}, journal = {International Journal of Wildland Fire}, volume = {29}, year = {2019}, month = {09/2019}, pages = {414-426}, abstract = {

Fire agencies are moving towards planning systems based on risk assessment; however, knowledge of the most effective way to quantify changes in risk to key values by application of prescribed fire is generally lacking. We present a quantification and inter-regional comparison of how risk to management values responds to variations in prescribed burning treatment rate. Fire simulations were run using the PHOENIX RapidFire fire behaviour simulator for two case study landscapes in interface zones in Tasmania and the Australian Capital Territory (ACT), Australia. A Bayesian network approach used these data to explore the influence of treatment and weather on risk from wildfire. Area burnt, length of powerline damaged and length of road damaged responded more strongly to treatment in the ACT than in Tasmania, whereas treatment mitigated house loss and life loss more strongly in Tasmania than the ACT. The effect of prescribed burning treatment rate on area burnt below minimum tolerable fire interval was similar in each case study landscape. Our study shows that the effectiveness of prescribed burning at mitigating area burnt by wildfire and other key values varies considerably across landscapes and values.

}, keywords = {Bushfire, Climate change, trends, Wildfire, wildland fire}, doi = {https://doi.org/10.1071/WF18135}, url = {https://www.publish.csiro.au/WF/WF18135}, author = {Brett Cirulis and Hamish Clarke and Matthias M. Boer and Trent Penman and Owen Price and Ross Bradstock} } @article {bnh-5615, title = {Quantification of inter-regional differences in risk mitigation from prescribed burning across multiple management values}, journal = {International Journal of Wildland Fire}, year = {2019}, month = {06/2019}, abstract = {

Fire agencies are moving towards planning systems based on risk assessment; however, knowledge of the most effective way to quantify changes in risk to key values by application of prescribed fire is generally lacking. We present a quantification and inter-regional comparison of how risk to management values responds to variations in prescribed burning treatment rate. Fire simulations were run using the PHOENIX RapidFire fire behaviour simulator for two case study landscapes in interface zones in Tasmania and the Australian Capital Territory (ACT), Australia. A Bayesian network approach used these data to explore the influence of treatment and weather on risk from wildfire. Area burnt, length of powerline damaged and length of road damaged responded more strongly to treatment in the ACT than in Tasmania, whereas treatment mitigated house loss and life loss more strongly in Tasmania than the ACT. The effect of prescribed burning treatment rate on area burnt below minimum tolerable fire interval was similar in each case study landscape. Our study shows that the effectiveness of prescribed burning at mitigating area burnt by wildfire and other key values varies considerably across landscapes and values.

}, keywords = {Bushfire, Climate change, trends, Wildfire, wildland fire}, doi = {https://doi.org/10.1071/WF18135}, url = {http://www.publish.csiro.au/WF/WF18135}, author = {Brett Cirulis and Hamish Clarke and Matthias M. Boer and Trent Penman and Owen Price and Ross Bradstock} } @article {bnh-6046, title = {Simulation study of grass fire using a physics-based model: striving towards numerical rigour and the effect of grass height on the rate of spread}, journal = {International Journal of Wildland Fire}, volume = {27}, year = {2018}, month = {11/2018}, pages = {800-814}, abstract = {

Grid-independent rate of spread results from a physics-based simulation are presented. Previously, such a numerical benchmark has been elusive owing to computational restrictions. The grid-converged results are used to systematically construct correlations between the rate of spread (RoS) and both wind speed and grass height, separately. The RoS obtained from the physics-based model is found to be linear with wind speed in the parameter range considered. When wind speed is varied, the physics-based model predicts faster RoS than the Mk III and V (McArthur) models (Noble\ et al.\ 1980) but slower than the CSIRO model (Cheney\ et al.\ 1998). When the grass height is varied keeping the bulk density constant, the fire front changes from a boundary layer flame mode to plume flame mode as the grass height increases. Once the fires are in plume mode, a higher grass height results in a larger heat release rate of the fire but a slower RoS.

}, keywords = {atmospheric boundary layer, operational model, Physics-based modelling, wildland fire, wind speed}, doi = {https://doi.org/10.1071/WF17126}, url = {http://www.publish.csiro.au/wf/WF17126}, author = {Khalid Moinuddin and Duncan Sutherland and William Mell} } @article {BF-4286, title = {Exploring the role of fire, succession, climate, and weather on landscape dynamics using comparative modeling}, journal = {Ecological Modelling}, volume = {266}, year = {2013}, month = {09/2013}, pages = {172-186}, chapter = {172}, abstract = {An assessment of the relative importance of vegetation change and disturbance as agents of landscape change under current and future climates would (1) provide insight into the controls of landscape dynamics, (2) help inform the design and development of coarse scale spatially explicit ecosystem models such as Dynamic Global Vegetation Models (DGVMs), and (3) guide future land management and planning. However, quantification of landscape change from vegetation development and disturbance effects is difficult because of the large space and long time scales involved. Comparative simulation modeling experiments, using a suite of models to simulate a set of scenarios, can provide a platform for investigating landscape change over more ecologically appropriate time and space scales that control vegetation and disturbance. We implemented a multifactorial simulation experiment using five landscape fire succession models to explore the role of fire and vegetation development under various climates on a neutral landscape. The simulation experiment had four factors with two or three treatments each: (1) fire (fire and no fire), (2) succession (dynamic and static succession), (3) climate (historical, warm-wet, warm-dry), and (4) weather (constant, variable). We found that, under historical climates, succession changed more area annually than fire by factors of 1.2 to 34, but one model simulated more landscape change from fire (factor of 0.1). However, we also found that fire becomes more important in warmer future climates with factors decreasing to below zero for most models. We also found that there were few differences in simulation results between weather scenarios with low or high variability. Results from this study show that there will be a shift from vegetation processes that control today{\textquoteright}s landscape dynamics to fire processes under future warmer and drier climates, and this shift means that detailed representations of both succession and fire should be incorporated into models to realistically simulate interactions between disturbance and vegetation.}, keywords = {Landscape dynamics, Landscape ecology, Model comparison, Simulation modeling, Succession, wildland fire}, doi = {http://dx.doi.org/10.1016/j.ecolmodel.2013.06.020}, url = {http://www.sciencedirect.com/science/article/pii/S030438001300313X}, author = {Robert E. Keane and Geoffrey J. Cary and Flannigan, Mike D. and Parsons, Russell A. and Davies, Ian D. and Karen J. King and Li, Chao and Ross Bradstock and Gill, A. Malcolm} } @article {BF-3999, title = {A spatial optimisation model for multi-period landscape level fuel management to mitigate wildfire impacts}, journal = {European Journal of Operational Research}, year = {2013}, abstract = {Elevated fuel loads are contributing to an increase in the occurrence of, and area burned by, severe wildfires in many regions across the globe. In an attempt to reverse this trend, fire and land management agencies are investing in extensive fuel management programs. However, the planning of fuel treatment activities poses complicated decision-making problems with spatial and temporal dimensions. Here, we present a mixed integer programming model for spatially explicit multi-period scheduling of fuel treatments. The model provides a flexible framework that allows for landscape heterogeneity and a range of ecological and operational considerations and constraints. The model{\textquoteright}s functionality is demonstrated on a series of hypothetical test landscapes and a number of implementation issues are discussed.}, keywords = {Fuel management, Integer programming, OR in natural resources, Spatial optimization, Wildfire, wildland fire}, doi = {10.1016/j.ejor.2013.07.026}, url = {http://www.sciencedirect.com/science/article/pii/S0377221713006073}, author = {Minas, James P. and John Hearne and Martell, David} } @proceedings {BF-2992, title = {Self-organization of Fire-prone Landscape Systems: Concepts, models and field evidence}, year = {2005}, month = {August 2005}, publisher = {Ecological Society of America}, address = {USA, United States of America }, keywords = {Australia, Self-organization, spatial patterns, wildland fire}, url = {http://abstracts.co.allenpress.com/pweb/esa2005/document/48216}, author = {Matthias M. Boer and Grierson, Pauline} }