@article {bnh-8329, title = {Analysis and characterisation of bushfire-meets-prescribed burn events from the 2019-20 fire season - Black Summer final report}, number = {683}, year = {2022}, month = {03/2022}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

The objective of this project was stated in the Research Services Agreement as: {\textquotedblleft}to develop a novel dataset that will capture information about individual bushfire-meets-prescribed burn events. The initial focus will be on those interactions that occurred during the 2019/20 fire season.{\textquotedblright} In other words, the project was to design a database that will allow evaluation of prescribed burns from planning stages to ultimate outcomes, and start using the data for some cases. In this report, we begin by outlining this dataset and its sources of information, though we have not populated it. Instead, we list potential evaluations that could be done with and conduct two evaluations with components of the data.

The core of the proposed fire-meets-fire dataset is matched reporting from the Burn Plan (before) and Burn Report (on completion), especially area, fuel, moisture and weather variables. Some of this is not routinely reported in the current Elements System (for example 21\% of burns had no actual area burnt recorded and most burns were missing fuel information). The dataset should also ingest information from fire severity mapping (which is now routine) and smoke impact. If the burn meets a bushfire a new range of information is available and should be ingested, including the severity of the bushfire within the burn. The advantage that the burn gave to firefighters is hard to gauge simply from fire severity, so additional information is needed, most importantly from firefighter interviews, but also by more detailed GIS examination of bushfire behavior.

There are many evaluations that could be done with this dataset, from simple metrics such as percent of planned area actually burnt, to refinement of weather prescriptions for burns to whole-of-program evaluations applied to all burns such as the severity analysis presented here.

Sections 3 and 4 are examples of whole of program evaluations. Section 4 is an analysis of severity reduction in the 2019/20 bushfires relating the occurrence of high severity fire in ~100,000 points to the fire history at those points, and controlling for vegetation, weather and topography. This found that in dry sclerophyll, recent burning (up to ~five years) reduced the probability of high severity fire and even more so if that previous burn was at low severity.

Section 4 uses visual interpretation of the 2019/20 bushfire severity and progression mapping to attribute each previous prescribed burn with its effect on the bushfire. This ranged from stopping the bushfire altogether (having a common boundary) to simple severity reduction (was the bushfire severity reduced in the burn?). We found that 30\% of burns from 2014 were encountered by the bushfires. Of these 509 burns, 13\% of them were aligned with the final fire boundary, 42\% of recent burns (one or two years old) caused some unburnt patches within the burn, and 68\% caused a severity reduction. Burns older than this had much less effect, and we found two cases where a burn left an unburnt shadow behind it (meaning shadows are very rare events). We were able to cross-reference our interpretation for 14 burns to interviews from another pilot project. This revealed broad agreement, but also highlighted several cases where a burn gave firefighters an advantage that could not be found in the GIS. Three of these were cases where the bushfire slowed down (sometimes for several days), allowing firefighters time to prepare. There were two cases where burns outside of the burn perimeter effectively reduced spotting activity.

The project demonstrates what can be done to evaluate prescribed burning programs and that a wide range of data is required to do this thoroughly. The 2019/20 bushfire season was extraordinary in many ways. Our analysis suggests that one of these ways was that prescribed burns only reduced fire behavior if they were one or two years old. Analyses of previous seasons generally find a longer lasting effect. Even so, there were many instances where prescribed burns helped firefighters, including in ways that are not obvious in GIS analyses.

}, keywords = {2019-20, analysis, black summer, Bushfire, characterisation, prescribed burn}, issn = {683}, author = {Owen Price and James Barker and Simin Rahmani and Wilkinson, Carrie and Donald MacDonald} } @article {bnh-8335, title = {Investigating the suitability of aviation tracking data for use in bushfire suppression effectiveness research}, year = {2022}, month = {04/2022}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Aircraft are an important part of bushfire suppression and their use is increasing. They were used heavily during the 2019/20 {\textquotedblleft}Black Summer{\textquotedblright} bushfire season in NSW and several inquiries have highlighted the need for research into their effectiveness.

Tracking equipment is becoming routinely deployed on aircraft and there is increasing availability of high-quality ancillary data such as aerial imagery and fire severity mapping. These allow detailed analyses of aircraft activities. However, the usefulness of the data needs to be evaluated, and the analysis needs to be informed by information about the tasking objectives of the aircraft and whether those objectives were met.

This project provides an initial investigation into the process of evaluating aerial suppression using these new data sources and interviews with personnel involved in the suppression activities.

Firebombing event data (drops/fills) from the 2019/2020 bushfire season in NSW from the National Aerial Firefighting Centre (NAFC){\textquoteright}s Arena database was provided by the NSW Rural Fire Service. This data included ~70000 aircraft suppression drop locations and times from aircraft that included helicopters (mainly large and medium helitaks), Single-Engine Air Tankers and Large Air Tankers. As an initial step, we examined the data for completeness, accuracy and errors, and described the data contents. This data was missing for most of the aircraft known to be dropping on the fires, especially the smaller ones. The type of drop (gel, water, retardant) was unknown in most cases, the quantity dropped was unknown in 45\% of cases, and the location for the end of drops was often unreliable.

We then tested methods to identify drop objectives based on relationships between drops data and other spatial data including building locations and weather. Using a combination of automated pattern matching and manual checking, the data can be used to identify cases where the objective was initial attack, extinguishing spot fires, asset protection, pre-emptive laying of retardant lines and direct attack. There were a few cases where the success or failure of the objective could be assessed purely with the spatial data. We also explored two particular analytical methods for determining objectives. First, we compared the distribution of Forest Fire Danger Index (FFDI, fire weather) during a fire and for the drops within that fire. This identified several fires for which a large proportion of the drops were more likely to be during extreme fire weather even though extreme weather was rare in that fire. Second, we compared the distribution of distance to houses between all parts of the fire and the drops at that fire. Here we found many fires where the drops were clustered closer to houses than if the drops were (hypothetically) spread evenly across the fire ground. These analyses are preliminary but show great potential.

We conducted 10 interviews with personnel who worked as Air Attack Supervisors during the 2019/20 season. Interviewees were knowledgeable and experienced, and expressed the view that the aerial program could be improved with further knowledge sharing and training. They provided a lot of general information about objectives, how they learned during the season, their views on limitations in aerial suppression, and their own capacity to document the process.

The interviews also highlighted several operational issues that warrant more investigation using a large number of aviation specialists and more specific questions. Chief among these are:

We conducted eight detailed case studies where there were interesting features in the drop data and insightful comments from the interviewees. These were particular days at a particular part of a fire. They included one example with multiple objectives playing out as one failed and the fire spread changed, several where property protection was the dominant objective (largely successful), one on spot fires, and two initial attacks, of which one succeeded and the other failed.\  The case studies demonstrate the power of the approach where spatial data and interview interpretation are combined.

The air drop data has the potential to enable deep analyses of aircraft use and effectiveness during real bushfire responses, especially when combined with other contextual information, such as objectives and environmental conditions. This will require more matching of the data to interviews to determine whether the drop data can be used in this way. We have started this process in this report, identifying clear clusters of activity related to weather and distance to houses, and cross-checking with interviews in the case study, and in some of these cases, the success could be judged. In order to realise the full potential of this approach, the completeness and accuracy of the drop data should be improved and interviews should become a routine part of the seasonal review process.

}, issn = {725}, author = {Heather Simpson and Michael Storey and Matt P Plucinski and Owen Price} } @article {bnh-8115, title = {Derivation of a Bayesian fire spread model using large-scale wildfire observations}, journal = {Environmental Modelling \& Software}, year = {2021}, month = {07/2021}, abstract = {

Models that predict wildfire rate of spread (ROS) play an important role in decision-making during firefighting operations, including fire crew placement and timing of community evacuations. Here, we use a large set of remotely sensed wildfire observations, and explanatory data (focusing on weather), to demonstrate a Bayesian probabilistic ROS modelling approach. Our approach has two major advantages: (1) Using actual wildfire observations, instead of controlled fire observations, makes models developed well-suited to wildfire prediction; (2) Bayesian modelling accounts for the complex nature of wildfire spread by explicitly considering uncertainty in the data to produce probabilistic ROS predictions. We show that highly informative probabilistic predictions can be made from a simple Bayesian model containing wind speed, relative humidity and soil moisture. We also compare Bayesian model predictions to those of widely used deterministic ROS models in Australia.

}, keywords = {Wildfire Bushfire Fire behaviour Bayesian Bayesian modelling Rate of Spread}, doi = {https://doi.org/10.1016/j.envsoft.2021.105127}, url = {https://www.sciencedirect.com/science/article/abs/pii/S1364815221001705}, author = {Michael Storey and Bedward, M. and Owen Price and Ross Bradstock and Jason J. Sharples} } @article {bnh-7795, title = {Experiments on the influence of spot fire and topography interaction on fire rate of spread}, journal = {PLOS ONE}, volume = {16}, year = {2021}, month = {01/2021}, abstract = {

Spotting is thought to increase wildfire rate of spread (ROS) and in some cases become the main mechanism for spread. The role of spotting in wildfire spread is controlled by many factors including fire intensity, number of and distance between spot fires, weather, fuel characteristics and topography. Through a set of 30 laboratory fire experiments on a 3 m x 4 m fuel bed, subject to air flow, we explored the influence of manually ignited spot fires (0, 1 or 2), the presence or absence of a model hill and their interaction on combined fire ROS (i.e. ROS incorporating main fire and merged spot fires). During experiments conducted on a flat fuel bed, spot fires (whether 1 or 2) had only a small influence on combined ROS. Slowest combined ROS was recorded when a hill was present and no spot fires were ignited, because the fires crept very slowly downslope and downwind of the hill. This was up to, depending on measurement interval, 5 times slower than ROS in the flat fuel bed experiments. However, ignition of 1 or 2 spot fires (with hill present) greatly increased combined ROS to similar levels as those recorded in the flat fuel bed experiments (depending on spread interval). The effect was strongest on the head fire, where spot fires merged directly with the main fire, but significant increases in off-centre ROS were also detected. Our findings suggest that under certain topographic conditions, spot fires can allow a fire to overcome the low spread potential of downslopes. Current models may underestimate wildfire ROS and fire arrival time in hilly terrain if the influence of spot fires on ROS is not incorporated into predictions.

}, keywords = {air flow, analysis of variance, Bushfire, combustion, fire research, fire suppression technology, fuels, rotors}, doi = {https://doi.org/10.1371/journal.pone.0245132}, url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0245132}, author = {Michael Storey and Owen Price and M. Almeida and Carlos Ribeiro and Ross Bradstock and Jason J. Sharples} } @article {bnh-8192, title = {Risk mitigation from prescribed burning in Kangaroo Island and Mount Lofty Ranges - Black Summer final report}, number = {690}, year = {2021}, month = {08/2021}, institution = {Bushfire and Natural Hazards CRC}, address = {MELBOURNE}, abstract = {

According to the Independent Review into South Australia{\textquoteright}s 2019-20 Bushfire Season, conditions were the worst on record with fires resulting in the loss of three human lives, 196 homes, 660 vehicles, 68,000 livestock, $200m of agricultural production. Around 280,000 ha were burnt by the fires, including total or partial burning of several National Parks.

The Bushfire and Natural Hazards CRC commissioned this project as part of a larger set of Black Summer fires research projects aimed at understanding the record-breaking fire season. This project focuses on answering questions about the effectiveness of prescribed burning, also known as hazard reduction burning, in mitigating risk in two areas affected by fires during the season: The Mount Lofty Ranges east of Adelaide, and Kangaroo Island.

The key questions were:

  1. How does risk respond to treatment in Kangaroo Island, an area with little formal quantification of prescribed burning benefits and costs?
  2. What was the risk in the leadup to the 2019-20 fire season in the Mt Lofty Ranges, and how will risk change in the next five years as a result of the implied fuel reduction from the fires, as well as alternative prescribed burning strategies?

These questions were answered using a well developed methodology combining large scale fire behaviour simulations and Bayesian risk quantification. Similar analyses have been carried out for a range of case study landscapes in southern Australia as part of the Hectares to tailor-made solutions CRC project, with results available online via the end-user tool the Prescribed Burning Atlas, and also the NSW Bushfire Risk Management Research Hub{\textquoteright}s projects for the NSW Bushfire Inquiry.

We found a clear relationship between the rate of prescribed burning and area subsequently burnt by wildfire in the Kangaroo Island case study. This translated into reductions in loss of life and property as well. Risk mitigation was more sensitive to edge treatment than landscape treatment, although both reduced risk. Conversely, increasing treatment (particularly at the edge) resulted in higher areas of the landscape exposed to vegetation being burnt below its minimum tolerable fire interval.

In the Mt Lofty Ranges, we found complex patterns of risk are likely in the aftermath of the 2019-20 fires. In the absence of further wildfire events, risk of area burnt is likely to rise substantially by 2025, regardless of prescribed burning rates, with a similar result for vegetation exposed to too frequent fire. However, risk sto life, property and infrastructure are projected to remain similar to current levels.

Our work contributes to the evidence base for prescribed burning planning in South Australia, with future work potentially examining new management values (e.g. smoke health costs, new biodiversity measures) and exploring empirical relationships between prescribed burning and fire-affected area in 2019-20.

}, keywords = {black summer, kangaroo island, mitigation, Mount Lofty Ranges, Prescribed burning, risk}, issn = {690}, author = {Hamish Clarke and Brett Cirulis and Owen Price and Ross Bradstock and Matthias M. Boer and Anthony Rawlins and Trent Penman} } @article {bnh-6874, title = {Analysis of Variation in Distance, Number, and Distribution of Spotting in Southeast Australian Wildfires}, journal = {Fire}, volume = {3}, year = {2020}, month = {04/2020}, abstract = {

Spotting during wildfires can significantly influence the way wildfires spread and reduce the chances of successful containment by fire crews. However, there is little published empirical evidence of the phenomenon. In this study, we have analysed spotting patterns observed from 251 wildfires from a database of over 8000 aerial line scan images capturing active wildfire across mainland southeast Australia between 2002 and 2018. The images were used to measure spot fire numbers, number of {\textquotedblleft}long-distance{\textquotedblright} spot fires (\> 500 m), and maximum spotting distance. We describe three types of spotting distance distributions, compare patterns among different regions of southeast Australia, and associate these with broad measures of rainfall, elevation, and fuel type. We found a relatively high correlation between spotting distance and numbers; however, there were also several cases of wildfires with low spot fire numbers producing very long-distance spot fires. Most long-distance spotting was associated with a {\textquotedblleft}multi-modal{\textquotedblright} distribution type, where high numbers of spot fires ignite close to the source fire and isolated or small clumps of spot fires ignite at longer distances. The multi-modal distribution suggests that current models of spotting distance, which typically follow an exponential-shaped distribution, could underestimate long-distance spotting. We also found considerable regional variation in spotting phenomena that may be associated with significant variation in rainfall, topographic ruggedness, and fuel descriptors. East Victoria was the most spot-fire-prone of the regions, particularly in terms of long-distance spotting.

}, keywords = {spot fire; spotting distance; spotting distribution; wildfire behaviour}, doi = {https://doi.org/10.3390/fire3020010}, url = {https://www.mdpi.com/2571-6255/3/2/10}, author = {Michael Storey and Owen Price and Ross Bradstock and Jason J. Sharples} } @article {bnh-6754, title = {Drivers of long-distance spotting during wildfires in south-eastern Australia}, journal = {International Journal of Wildland Fire}, year = {2020}, month = {03/2020}, abstract = {

We analysed the influence of wildfire area, topography, fuel, surface weather and upper-level weather conditions on long-distance spotting during wildfires. The analysis was based on a large dataset of 338 observations, from aircraft-acquired optical line scans, of spotting wildfires in south-east Australia between 2002 and 2018. Source fire area (a measure of fire activity) was the most important predictor of maximum spotting distance and the number of long-distance spot fires produced (i.e. \>500 m from a source fire). Weather (surface and upper-level), vegetation and topographic variables had important secondary effects. Spotting distance and number of long-distance spot fires increased strongly with increasing source fire area, particularly under strong winds and in areas containing dense forest and steep slopes. General vegetation descriptors better predicted spotting compared with bark hazard and presence variables, suggesting systems that measure and map bark spotting potential need improvement. The results from this study have important implications for the development of predictive spotting and wildfire behaviour models.

}, keywords = {Fire behaviour, line scan, spot fire}, doi = {https://doi.org/10.1071/WF19124}, url = {https://www.publish.csiro.au/wf/WF19124}, author = {Michael Storey and Owen Price and Jason J. Sharples and Ross Bradstock} } @article {bnh-7389, title = {From hectares to tailor-made solutions for risk mitigation {\textendash} final project report}, number = {615}, year = {2020}, month = {09/2020}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

We are pleased to present the 2020 Final Report for the Bushfire and Natural Hazards CRC project, {\textquotedblleft}From hectares to tailor-made solutions for risk mitigation: systems to deliver effective prescribed burning across Australian ecosystems{\textquotedblright}.

Prescribed burning is a central feature of contemporary fire management, not just in Australia but in fire-prone countries around the world. Yet we lack a firm quantitative basis for understanding and comparing its effectiveness at mitigating risk across different regions. This project aims to address these gaps and provide critical support to agency decision makers across southern Australia by undertaking a systematic investigation of the drivers of prescribed burning effectiveness across the region. This project will thus support fire managers in transitioning from hectare targets to a set of tailor-made, risk-based approaches.

The project is divided into two phases: fire behaviour accounting and risk accounting. At the heart of the project is predictive modelling of the effect of prescribed burning on subsequent bushfire (wildfire) behaviour. In this project we combine ignition likelihood modelling, fuel type and arrangement from fire management agencies, weather representing all possible local fire weather conditions from Bureau of Meteorology and fire history including wildfire and variable combinations of edge and landscape treatments, applied to agency or model-derived burn blocks. From thousands of simulations, key outputs such as fire size and intensity are used estimate impacts on key management values: house loss, life loss, length of road damaged, length of powerline damaged and area burnt below minimum tolerable fire interval. We use Bayesian decision networks to estimate risk mitigation, including cost, available through different treatments. Local trajectories of cost for given treatment rates and locations can then be tracked and compared between regions, allowing identification of the most cost-effective prescribed burning strategies, either overall or for a given management value.

The key finding of the project is that the effectiveness of prescribed burning at mitigating area burnt by bushfire and other key values varies considerably across landscapes and values. That is, there is no one-size-fits-all solution to prescribed burning. This has major implications for fire managers, suggesting that tailored prescribed burning solutions are possible, based on the unique risk mitigation profile for any given suite of management values in that region. Further details are included in this report and journal articles listed herein.

While the project now draws to a close, its findings live on in the Prescribed Burning Atlas, a dedicated website for fire managers, researchers and anyone else interested in using our project to support their planning, decision making and communication. The Prescribed Burning Atlas will provide a geographically-based summary of risk for decision makers in an accessible, user friendly format. Our project is unique in placing the design and delivery of this utilisation output at its heart. Active involvement of end-users throughout 2020 and beyond will be crucial in ensuring uptake and translation into outcomes for end-users and the communities they serve. From a research perspective, key outstanding questions include quantification of risk mitigation for new values (smoke effects on human health, biodiversity measures, cultural burning) and expansion of the approach to represent the full richness of planned and unplanned landscape fire over time.

}, keywords = {ecosystems, hectares, mitigation, Prescribed burning, risk, systems, tailor-made solutions}, issn = {615}, author = {Hamish Clarke and Brett Cirulis and Trent Penman and Owen Price and Matthias M. Boer and Ross Bradstock} } @article {bnh-5654, title = {Climate change effects on the frequency, seasonality and interannual variability of suitable prescribed burning weather conditions in south-eastern Australia}, journal = {Agricultural and Forest Meteorology}, volume = {271}, year = {2019}, month = {06/2019}, chapter = {148-157}, abstract = {

Despite the importance of prescribed burning in contemporary fire management, there is little understanding of how climate change will influence the weather conditions under which it is deployed. We provide quantitative estimates of potential changes in the number of prescribed burning days in coastal NSW in south-eastern Australia, a fire-prone area dominated by dry sclerophyll forests. Burning days are calculated from an objectively designed regional climate model ensemble using three definitions of suitable weather conditions based on: a literature search (Literature), actual weather observed during recorded prescribed burns (Observed) and operational guidelines (Operational). Contrary to some claims, evidence for a decrease in prescribed burning days under projected future climates is weak. We found a complex pattern of changes, with the potential for substantial and widespread increases in the current burning seasons of autumn (March-May) and spring (August-October). Projected changes were particularly uncertain in northern NSW, spanning substantial increases and decreases during autumn. The magnitude of projected changes in the frequency of burning days was highly sensitive to which definition of suitable weather conditions was used, with a relatively small change for the Operational definition (+0.3 to +1.9 days per year across the study area) and larger ranges for the Observed (+0.2 to +7.9 days) and Literature (+1.7 to +6.2 days) definitions. Interannual variability in the number of burning days is projected to increase slightly under projected climate change. Our study highlights the need for a better understanding of the weather conditions required for safe and effective prescribed burning. Our analysis provides practitioners with quantitative information to assess their exposure to a range of potential changes in the frequency, seasonality and variability of prescribed burning weather conditions.

}, keywords = {Burn window, Climate change, Fire weather, Global warming, Hazard reduction, Prescribed burning, prescribed fire}, doi = {https://doi.org/10.1016/j.agrformet.2019.03.005}, url = {https://www.sciencedirect.com/science/article/pii/S0168192319301091}, author = {Hamish Clarke and Bruce Tran and Matthias M. Boer and Owen Price and Belinda Kenny and Ross Bradstock} } @article {bnh-5697, title = {From hectares to tailor-made solutions for risk mitigation: annual project report 2018-19}, number = {487}, year = {2019}, month = {07/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

We are pleased to present the 2018-2019 Annual Report for the Bushfire and Natural Hazards CRC project, {\textquotedblleft}From hectares to tailor-made solutions for risk mitigation: systems to deliver effective prescribed burning across Australian ecosystems{\textquotedblright}. The project aims to provide critical support to agency decision makers across southern Australia by undertaking a systematic investigation of the drivers of prescribed burning effectiveness across the region. This report describes the background, research approach and key milestones since the previous Annual Report in 2017-2018. The report focuses on the research outputs informing the development of the Prescribed Fire Atlas. The project has now delivered a rich, layered dataset capable of addressing nuanced questions about the quantitative risk reduction available through prescribed burning for multiple management values in varying landscapes. The project is now entering its final phase as we complete climate change and cost-effectiveness analyses and launch the Prescribed Burning Atlas in 2019/20. The Prescribed Burning Atlas will provide geographically based summary of risk for decision makers in an accessible, user friendly format. Our project is unique in placing the design and delivery of this utilisation output at the heart of the project. Active involvement of end users throughout 2020 and beyond will be crucial in ensuring uptake and translation into outcomes for end users and the communities they serve.

}, keywords = {cost-effective, ecosystems, fire management, Prescribed burning}, author = {Hamish Clarke and Owen Price and Matthias M. Boer and Brett Cirulis and Trent Penman and Ross Bradstock} } @conference {bnh-6396, title = {A new decision support tool for prescribed burning risk assessment}, booktitle = {Bushfire and Natural Hazards CRC Research Day AFAC19}, year = {2019}, month = {12/2019}, address = {Melbourne}, abstract = {

In most Australian jurisdictions, the use of prescribed fire is promoted on the basis of its efficacy in mitigation of risk. Despite this, formal attempts to evaluate effects on risk to people, property and environmental values across different jurisdictions are generally lacking. In particular, there is no basis for assessing the generality of attempts to predict risk in response to any particular strategy for use of prescribed fire (e.g. the 5per cent target recommended by the 2009 Victorian Bushfires Royal Commission). General principles therefore need to be developed about how to apply a risk-based approach across widely varying environments, human communities and combinations of key management values.

In this Bushfire and Natural Hazards Cooperative Research Centre project, researchers from the University of Wollongong, Western Sydney University and the University of Melbourne have come together with end users across southern Australia to design a project to systematically investigate how risk to any particular management value will respond to variations in the spatial location and rates of treatment. Project outputs are currently being moulded for utilisation by end users in a dedicated tool, the Prescribed Fire Atlas, which will guide the implementation of {\textquoteleft}tailor-made{\textquoteright} prescribed burning strategies to suit the biophysical, climatic and human context of all bioregions across southern Australia.

}, keywords = {decision support, Fire, perscibed burning, risk management}, url = {https://knowledge.aidr.org.au/resources/australian-journal-of-emergency-management-monograph-series/}, author = {Hamish Clarke and Brett Cirulis and Ross Bradstock and Matthias M. Boer and Trent Penman and Owen Price} } @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-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-6109, title = {A Temporal Framework of Large Wildfire Suppression in Practice, a Qualitative Descriptive Study}, journal = {Forests}, volume = {10}, year = {2019}, month = {10/2019}, pages = {884}, abstract = {

Suppression activities on large wildfires are complicated. Existing suppression literature does not take into account this complexity which leaves existing suppression models and measures of resource productivity incomplete. A qualitative descriptive analysis was performed on the suppression activities described in operational documents of 10 large wildfires in Victoria, Australia. A five-stage classification system summarises suppression in the everyday terms of wildfire management. Suppression can be heterogeneous across different sectors with different stages occurring across sectors on the same day. The stages and the underlying 20 suppression tasks identified provide a fundamental description of how suppression resources are being used on large wildfires. We estimate that at least 57\% of resource use on our sample of 10 large wildfires falls outside of current suppression modelling and productivity research.

}, keywords = {wildfire; suppression; fire management; resource use}, doi = {https://doi.org/10.3390/f10100884}, url = {https://www.mdpi.com/1999-4907/10/10/884}, author = {Heather Simpson and Ross Bradstock and Owen Price} } @article {bnh-5035, title = {From hectares to tailor-made solutions for risk mitigation: annual project report 2017-18}, year = {2018}, month = {10/2018}, institution = {Bushfire and Natural Hazards CRC}, abstract = {

This report describes the background, research approach and key milestones since the 2016-2017 Annual Report. The report focuses on the analysis of fire spread simulations for two case study landscapes: the ACT and Tasmania. The analysis demonstrates that it is possible to investigate prescribed burning effectiveness at risk mitigation across a range of treatment levels, management values and landscapes, by placing them on a common baseline of risk.

}, issn = {421}, author = {Hamish Clarke and Owen Price and Matthias M. Boer and Brett Cirulis and Trent Penman and Ross Bradstock} } @article {bnh-5194, title = {How do weather and terrain contribute to firefighter entrapments in Australia?}, journal = {International Journal of Wildland Fire}, volume = {27}, year = {2018}, month = {02/2018}, pages = {85-98}, chapter = {85}, abstract = {

Adverse weather conditions and topographic influences are suspected to be responsible for most entrapments of firefighters in Australia. A lack of temporally and spatially coherent set of data however, hinders a clear understanding of the contribution of each weather type or terrain driver on these events. We investigate coronial inquiries and internal fire agencies reports across several Australian states from 1980 to 2017 and retrieve 45 entrapments. A first analysis reveals that most entrapments happen during large fires and that the number of deaths has decreased over the last few decades. Comparing the meteorological and topographical conditions of the entrapments with the conditions of a reference set of fires without entrapment, we build a linear regression model that identifies the main contributors to firefighter entrapment. A change in wind direction, which was associated with 42\% of the incidents examined, is the main factor contributing to entrapments. Interaction between strong winds and steep slopes also influences the likelihood of entrapment and suggests that dynamic fire behaviours may also play important roles. As further details of this relationship between dynamic fire propagation and firefighter entrapment is now required, the understanding of weather and terrain contribution is a first step to produce comprehensive safety guidance.

}, doi = {https://doi.org/10.1071/WF17114}, url = {https://www.publish.csiro.au/WF/WF17114}, author = {Lahaye, S and Jason J. Sharples and Stuart Matthews and Heemstra, S and Owen Price and Badlan, R} } @conference {bnh-4774, title = {A systematic exploration of the potential for bushfire risk mitigation with prescribed burning}, booktitle = {AFAC18}, year = {2018}, month = {09/2018}, publisher = {Bushfire and Natural Hazards CRC}, organization = {Bushfire and Natural Hazards CRC}, address = {Perth}, abstract = {

Fire regimes vary widely across Australian ecosystems as a function of climate, fuel, terrain and ignition variations. Fundamentally such variation will not only shape the way that prescribed burning can reduce risk to human and environmental assets but also the scope for effective treatment. While many agencies are moving toward planning systems based on risk assessment, knowledge of the best way to use prescribed fire to reduce risk to key values is generally lacking. The BNHCRC Project, {\textquotedblleft}From hectares to tailor-made solutions for prescribed burning{\textquotedblright}, combines simulation and empirical approaches to improve our understanding of how risk to any particular management value will respond to variations in the spatial location and rates of treatment. Here, we present the modelling framework and key results for two landscapes, Tasmania and the Australian Capital Territory. We run a large number of simulations using the PHOENIX RapidFire model, investigating the interaction between fuel treatment and location under various weather scenarios. Key outputs for risk assessment include area burnt, house loss, life loss, roads and powerlines damaged, environmental cost and economic cost. Across both case study landscapes, greater levels of prescribed burning tend to result in reduced wildfire impacts on all risks. However, there is considerable variation in the rate of reduction in risk, including the amount of treatment required to achieve key targets. Further, the particular combination of weather factors underpinning given fire weather conditions (e.g. temperature vs wind driven) can substantially impact the overall level of risk, as well as the response to prescribed burning.\ 

}, author = {Brett Cirulis and Hamish Clarke and Ross Bradstock and Matthias M. Boer and Trent Penman and Owen Price} } @article {bnh-4203, title = {From hectares to tailor-made solutions for risk mitigation - systems to deliver effective prescribed burning across Australian ecosystems: annual project report 2016-17}, number = {310}, year = {2017}, month = {09/2017}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

We are pleased to present the 2016-2017 Annual Report for the Bushfire and Natural Hazards CRC project, From hectares to tailor-made solutions for risk mitigation: systems to deliver effective prescribed burning across Australian ecosystems. By undertaking a systematic investigation of the drivers of prescribed burning effectiveness across southern Australia, the project will provide critical support to agency decision makers across the region.

This report describes the project goals, methods and activities since the 2015-2016 Annual Report. The report focuses on initial results from a key project component: fire spread simulations in a range of case study landscapes throughout southern Australia. Results are presented in detail for case studies in East Central Victoria, Adelaide, the ACT and Hobart. This initial suite of simulations provides good evidence that there is substantial variation between case study landscapes in the response of key risks to different rates of prescribed burning. Further simulations in combination with other project methodologies will provide further evidence about this critical issue.

The report also details progress on data acquisition, empirical analyses and stakeholder engagement, which form the other key activities of the project to date. Finally, we are graetful to Naomi Stephens and Felipe Aires, our End User representatives from the NSW Office of Environment and Heritage, for providing an insight into the project{\textquoteright}s progress from a stakeholder perspective.

}, issn = {310}, author = {Hamish Clarke and Owen Price and Matthias M. Boer and Brett Cirulis and Trent Penman and Ross Bradstock} } @conference {bnh-4333, title = {What are the safety implications of dynamic fire behaviours?}, booktitle = {22nd International Congress on Modelling and Simulation}, year = {2017}, month = {12/2017}, address = {Hobart}, abstract = {

Many firefighters in the world have been injured or killed due to a forest fire entrapment, caught by the fire heat or smoke. Some case studies have pointed out that dynamic fire behaviour may have played a role. We investigate here how changes in wind direction, channelling (i.e. vorticity-driven lateral spread on a leeward slope) and long distance spotting could contribute to entrapments through a process model, simplified in Figure 1. There are three situations likely to entrap firefighters:

We review fire agencies archives in Australasia and Europe from 1979 to 2017 and retrieve 106 entrapments, investigating weather, terrain and location of fire front during entrapment. We also compare the Australasian subset with fires without entrapment using a binomial regression function.

In Australia, changes in wind direction induced by cold front passes is the main factor contributing to entrapment. These sudden changes in wind direction switch long smooth burning flanks of fire in violent fronts and lead to S1 situations. S2, sudden lateral spread, occurs in rough terrain. There, leeward slopes may generate channelling, causing entrapment several hundred meters far away from the fire flank. S3 appears when fire danger index reaches highest values. When fuel drought combines with adverse weather conditions, mass spotting propagates fire at long distance. Then, firefighters may be entrapped whatever the terrain.

This work improves our understanding of the process from dynamic fire behaviour to firefighter entrapment. Identifying three different situations, the model should help fire agencies to adapt their safety warnings regarding the local daily conditions.

}, author = {Lahave, S and Jason J. Sharples and Stuart Matthews and Heemstra, S and Owen Price} } @article {bnh-3410, title = {Resolving future fire management conflicts using multi-criteria decision making}, journal = {Conservation Biology}, volume = {30}, year = {2016}, month = {02/2016}, pages = {196-205}, chapter = {196}, abstract = {

Management strategies to reduce the risks to human life and property from wildfire commonly involve burning native vegetation. However, planned burning can conflict with other societal objectives such as human health and biodiversity conservation. These conflicts are likely to intensify as fire regimes change under future climates and as growing human populations encroach farther into fire-prone ecosystems. Decisions about managing fire risks are therefore complex and warrant more sophisticated approaches than are typically used. We applied a multicriteria decision making approach (MCDA) with the potential to improve fire management outcomes to the case of a highly populated, biodiverse, and flammable wildland{\textendash}urban interface. We considered the effects of 22 planned burning options on 8 objectives: house protection, maximizing water quality, minimizing carbon emissions and impacts on human health, and minimizing declines of 5 distinct species types. The MCDA identified a small number of management options (burning forest adjacent to houses) that performed well for most objectives, but not for one species type (arboreal mammal) or for water quality. Although MCDA made the conflict between objectives explicit, resolution of the problem depended on the weighting assigned to each objective. Additive weighting of criteria traded off the arboreal mammal and water quality objectives for other objectives. Multiplicative weighting identified scenarios that avoided poor outcomes for any objective, which is important for avoiding potentially irreversible biodiversity losses. To distinguish reliably among management options, future work should focus on reducing uncertainty in outcomes across a range of objectives. Considering management actions that have more predictable outcomes than landscape fuel management will be important. We found that, where data were adequate, an MCDA can support decision making in the complex and often conflicted area of fire management.

}, doi = {10.1111/cobi.12580}, url = {http://onlinelibrary.wiley.com/doi/10.1111/cobi.12580/abstract}, author = {Don A. Driscoll and Michael Bode and Ross Bradstock and David A. Keith and Trent Penman and Owen Price} } @article {bnh-3128, title = {The role of weather, past fire and topography in crown fire occurrence in eastern Australia}, journal = {International Journal of Wildland Fire}, volume = {25}, year = {2016}, month = {09/2016}, abstract = {

We analysed the influence of weather, time since fire (TSF) and topography on the occurrence of crown fire, as mapped from satellite imagery, in 23 of the largest wildfires in dry sclerophyll forests in eastern Australia from 2002 to 2013. Fires were analysed both individually and as groups. Fire weather was the most important predictor of crown consumption. TSF (a surrogate for fuel accumulation) had complex nonlinear effects that varied among fires. Crown fire likelihood was low up to 4 years post-fire, peaked at ~10 years post-fire and then declined. There was no clear indication that recent burning became more or less effective as fire weather became more severe. Steeper slope reduced crown fire likelihood, contrary to the assumptions of common fire behaviour equations. More exposed areas (ridges and plains) had higher crown fire likelihood. Our results suggest prescribed burning to maintain an average of 10 years{\textquoteright} TSF may actually increase crown fire likelihood, but burning much more frequently can be effective for risk reduction. Our results also suggest the effects of weather, TSF and slope are not adequately represented in the underlying equations of most fire behaviour models, potentially leading to poor prediction of fire spread and risk.

}, url = {http://www.publish.csiro.au/WF/WF15171}, author = {Michael Storey and Owen Price} } @article {bnh-3432, title = {Biogeographical variation in the potential effectiveness of prescribed fire in south-eastern Australia}, journal = {Journal of Biogeography}, volume = {42}, year = {2015}, month = {09/2015}, pages = {2234-2245}, chapter = {2234}, abstract = {

Aim

Prescribed fire is a common land management for reducing risks from unplanned fires. However, the universality of such effectiveness remains uncertain due to biogeographical variation in fuel types, climatic influences and fire regimes. Here, we explore biogeographical patterns in the effectiveness of prescribed fire by calculating leverage (the reduction in unplanned area burnt resulting from recent previous area burnt) across south-eastern Australia over a 25\ year period.

Location

The 30 bioregions of south-eastern Australia.

Methods

We quantified leverage in each bioregion from fire records from 1975{\textendash}2009, controlling for variation in annual weather. We also identified potential drivers of variation in leverage by relating the bioregional leverage values to measures of fuel type and growth, climate, and weather extremes.

Results

Leverage was inferred in four bioregions while in the other 26 bioregions no leverage was detected or prescribed fire had the opposite effect (fire-follows-fire). Leverage occurred in the forested eastern section of the study area, where rainfall, fuel load and fire activity is high and fire weather is mild. In all bioregions, weather was a stronger predictor than past-fire extent of area burnt in a particular year.

Main conclusions

Our analysis of leverage shows that the effectiveness of prescribed fire varies regionally in predictable ways, which means that fuel management strategies applied in one region are not necessarily applicable in another. In most bioregions prescribed burning is likely to have very little effect on subsequent extent of unplanned fire, and even in regions where leverage occurs, large areas of treatment are required to substantially reduce the area burned by unplanned fire.

}, doi = {10.1111/jbi.12579}, url = {http://onlinelibrary.wiley.com/doi/10.1111/jbi.12579/abstract}, author = {Owen Price and Trent Penman and Ross Bradstock and Matthias M. Boer and Hamish Clarke} } @article {bnh-3845, title = {Reducing the risk of house loss due to wildfires}, journal = {Environmental Modelling and Software}, volume = {67}, year = {2015}, month = {05/2015}, pages = {12-25}, chapter = {12}, abstract = {

Wildfires will continue to reach people and property regardless of management effort in the landscape. House-based strategies are therefore required to complement the landscape strategies in order to reduce the extent of house loss. Here we use a Bayesian Network approach to quantify the relative influence of preventative and suppressive management strategies on the probability of house loss in Australia. Community education had a limited effect on the extent to which residents prepared their property hence a limited effect on the reduction in risk of house loss, however hypothetically improving property preparedness did reduce the risk of house loss. Increasing expenditure on suppression resources resulted in a greater reduction in the risk of loss than preparedness. This increase had an interaction effect with increasing the distance between vegetation and the houses. The extent to which any one action can be implemented is limited by social, environmental and economic factors.

}, doi = {10.1016/j.envsoft.2014.12.020}, url = {http://www.sciencedirect.com/science/article/pii/S1364815214003776?via\%3Dihub}, author = {Trent Penman and Ann E. Nicholson and Ross Bradstock and Luke Collins and Sandra H. Penman and Owen Price} } @article {BF-3787, title = {Modelling the potential for prescribed burning to mitigate carbon emissions from wildfires in fire-prone forests of Australia}, year = {2012}, url = {http://www.publish.csiro.au/paper/WF11023.htm}, author = {Gill, A. Malcolm and Hutley, LB and Garry D. Cook and Jeremy Russell-Smith and Stefan Maier and Roxburgh, Stephen and Meyer, C.P. (Mick) and Damian J. Barrett and Keith, H and Ross Bradstock and Geoffrey J. Cary and Owen Price and Williams, RJ} } @article {BF-3095, title = {Prescribed burning: how can it work to conserve the things we value?}, journal = {International Journal of Wildland Fire}, volume = {20}, year = {2011}, month = {2011}, pages = {721}, abstract = {Prescribed burning is a commonly applied management tool, and there has been considerable debate over the efficacy of its application. We review data relating to the effectiveness of prescribed burning in Australia. Specifically, we address two questions: (1) to what extent can fuel reduction burning reduce the risk of loss of human life and economic assets posed from wildfires? (2) To what extent can prescribed burning be used to reduce the risk of biodiversity loss? Data suggest that prescribed burning can achieve a reduction in the extent of wildfires; however, at such levels, the result is an overall increase in the total area of the landscape burnt. Simulation modelling indicates that fuel reduction has less influence than weather on the extent of unplanned fire. The need to incorporate ecological values into prescribed burning programmes is becoming increasingly important. Insufficient data are available to determine if existing programs have been successful. There are numerous factors that prevent the implementation of better prescribed burning practices; most relate to a lack of clearly defined, measurable objectives. An adaptive risk management framework combined with enhanced partnerships between scientists and fire-management agencies is necessary to ensure that ecological and fuel reduction objectives are achieved.}, doi = {10.1071/WF09131}, author = {Trent Penman and Christie, Fiona J. and Andersen, A. N. and Ross Bradstock and Geoffrey J. Cary and Henderson, M. K. and Owen Price and Tran, C. and Wardle, G. M. and Williams, RJ and York, Alan} } @article {BF-2369, title = {Efficacy of permanent firebreaks and aerial prescribed burning in western Arnhem Land, Northern Territory, Australia}, journal = {International Journal of Wildland Fire}, volume = {16}, year = {2007}, month = {2007}, pages = {295}, abstract = {We investigated the efficacy of firebreaks in the prevention of wildfires in the Arnhem Land Plateau, a vast, rugged and sparsely populated region with high biodiversity value and frequent wildfires. A total of 623 events where a fire met a permanent firebreak (cliffs, stream order, tracks and roads) in different fire seasons were compiled. Cliffs were more effective than streams at stopping fires, which were more effective than roads. Larger streams were more effective than small ones. The largest streams stop 75\% of early dry season fires, but there are no firebreak types with more than 50\% likelihood of stopping a late dry season fire. Geographic Information System (GIS) surfaces of the relative density of the three firebreak features in the landscape were randomly sampled and compared with the total number of fires and late dry season fires using generalised linear modelling. Several of the density variables were weakly but significantly related to fire frequency, and it appears that late dry season fires are influenced by features at a larger scale (16-km radius) than total fires (4 km). The Aerial Prescribed Burning program for 2004 was studied to identify how effective it was at stopping subsequent wildfires by dividing ignition lines into 137 5-km sections. Only 20\% of sections achieved a 100\% burn and where gaps occurred, a subsequent fire was 88\% likely to penetrate the line. Firebreaks are not certain instruments for fire management in this area.}, doi = {10.1071/WF06039}, author = {Owen Price and Andrew C. Edwards and Jeremy Russell-Smith} }