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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...
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... Turbulence is the main feature of the ABL, which plays a crucial role in mixing the air, contributing to the combustion processes and can affect fire behaviour, aiding or hindering the fire's spread (Sun et al., 2006(Sun et al., , 2009 For instance, Katurji et al. (2023) demonstrated from experimental burns that fire-induced turbulence modifies the ambient flow field in the roughness boundary layer. In addition, the heating of fire creates a turbulent environment, sometimes producing extreme phenomena such as fire swirls (Forthofer & Goodrick, 2011;Seto & Clements, 2011) or terrain-scale vortices induced by fire spreading laterally (Simpson et al., 2017). For a better understanding of how the evolution of the ABL influences fire behaviour, large-eddy simulations (LES) are extensively used (Ong et al., 2022;Potter, 2012). ...
The fire danger is particularly sensitive to meteorological conditions. The present study discusses the atmospheric conditions during three periods to evaluate how they can increase fire danger. A set of three convection‐permitting simulations was configured at 2.5 km resolution using the Meso‐NH model. In the first period, the intense surface heating induced by a heatwave favoured the development of the Iberian thermal low in July 2019, leading to the formation of precipitating systems and resulting in convective outflows that affected the central Iberian Peninsula. The outflows were shown to be an important feature in evaluating fire danger during the period; however, the simulation also highlighted the orographic effect as another phenomenon playing an important role in fire development and consequently enhancing the fire danger in some regions such as in the extreme southwest of Portugal. The orographic effect in this specific region was identified and analyzed in detail for two megafire events that occurred in Monchique in August 2003 and 2018. The Monchique Mountain's shape and orientation interacting with the airflow induced upslope and downslope winds that favoured the rapid propagation of the fire fronts in August 2018. The third experiment showed that the circulation of a sea breeze from the southern coast of Portugal may act as an enhancer for fire danger in the region when interacting with the regional mountain, such as verified in the 2003 megafire. The study shows that the fire danger over specific regions can be increased by different atmospheric phenomena and explored from atmospheric modelling. The convective outflows were an important factor enhancing fire danger; however, the orographic effect was confirmed as the main factor producing two megafires events in the extreme southwest of Portugal.
... It is well understood that wildfire suppression efforts track fire growth rates and fire sizes [6] (Figure 2). Once a fire reaches a critical size threshold, it is no longer possible to extinguish the fire [7], and as the fire grows, the objective of firefighting changes from containment and asset protection to mounting protracted firefighting campaigns to control the spread of the wildfire across landscapes. ...
Achieving sustainable coexistence with wildfires in the Anthropocene requires skilful integrated fire observations, fire behaviour predictions, forecasts of fire risk, and projections of change to fire climates. The diverse and multiscale approaches used by the atmospheric sciences, to understand geographic patterns, temporal trends and likely trajectories of weather and climate, provide a role model for how multiscale assessments of fire danger can be formulated and delivered to fire managers, emergency responders and at-risk communities. Adaptation to escalating risk of fire disasters requires specialised national agencies, like weather services, that provide to provide a diverse range of products to enable detection and near and longer-range prediction of landscape fire activity.
... Prescribed fires will help reduce the costs of fire management and suppression. Identifying and suppressing spot fire requires sufficient allocation of ground crews, air tankers, Unmanned Ariel Devices (UAVs), or other resources across the potential spot fire range to conduct fire suppression tasks and asset protection [68][69][70]. We found that woody encroachment substantially increased potential spot fire distance and subsequently the amount of area that needed to be monitored during the application of prescribed fire, indicating there is higher risk associated with applying prescribed burns after encroachment has already begun. ...
Woody encroachment is one of the greatest threats to grasslands globally, depleting a suite of ecosystem services, including forage production and grassland biodiversity. Recent evidence also suggests that woody encroachment increases wildfire danger, particularly in the Great Plains of North America, where highly volatile Juniperus spp. convert grasslands to an alternative woodland state. Spot-fire distances are a critical component of wildfire danger, describing the distance over which embers from one fire can cause a new fire ignition, potentially far away from fire suppression personnel. We assess changes in spot-fire distances as grasslands experience Juniperus encroachment to an alternative woodland state and how spot-fire distances differ under typical prescribed fire conditions compared to conditions observed during wildfire. We use BehavePlus to calculate spot-fire distances for these scenarios within the Loess Canyons Experimental Landscape, Nebraska, U.S.A., a 73,000-ha ecoregion where private-lands fire management is used to reduce woody encroachment and prevent further expansion of Juniperus fuels. We found prescribed fire used to control woody encroachment had lower maximum spot-fire distances compared to wildfires and, correspondingly, a lower amount of land area at risk to spot-fire occurrence. Under more extreme wildfire scenarios, spot-fire distances were 2 times higher in grasslands, and over 3 times higher in encroached grasslands and Juniperus woodlands compared to fires burned under prescribed fire conditions. Maximum spot-fire distance was 450% greater in Juniperus woodlands compared to grasslands and exposed an additional 14,000 ha of receptive fuels, on average, to spot-fire occurrence within the Loess Canyons Experimental Landscape. This study demonstrates that woody encroachment drastically increases risks associated with wildfire, and that spot fire distances associated with woody encroachment are much lower in prescribed fires used to control woody encroachment compared to wildfires.
... To do this effectively, suppression efforts must reduce the total area burnt by a wildfire (Arienti et al. 2006;Plucinski 2012Plucinski , 2019b. However, if fires escape initial attack, they can become large, costly to control, and difficult to manage (Gebert and Black 2012;Dunn et al. 2017;Simpson et al. 2019). Additionally, when suppression resources are spread unevenly across jurisdictions it can be more difficult to maintain control over multiple fires because resources are overloaded (Huber-Stearns et al. 2019). ...
... In Australia, most previous studies into the factors driving suppression success have used limited datasets of only a few fire events Plucinski 2012; although see Collins et al. 2018). Additionally, much of the research addresses operational techniques for suppressing wildfires (Plucinski 2019b;Plucinski et al. 2019;Simpson et al. 2019Simpson et al. , 2021, as opposed to identifying the variables most important for determining containment probability (Collins et al. 2018). Here, we use a Random Forest (RF) modelling approach to identify the key environmental factors and management decisions driving suppression success in Victoria, Australia. ...
Background Wildfire suppression is becoming more costly and dangerous as the scale and severity of impacts from fires increase under climate change. Aims We aim to identify the key environmental and management variables influencing containment probability for forest fires in Victoria and determine how these change over time. Methods We developed Random Forest models to identify variables driving fire containment within the first 24 h of response. We used a database of ~12 000 incident records collected across Victoria, Australia. Key results Response time, fire size at first attack, number of ground resources deployed (e.g. fire fighters), ignition cause, and environmental factors that influence fire spread (e.g. elevation, humidity, wind, and fuel hazard) were key drivers of suppression success within the first 24 h. However, certainty about the factors influencing suppression reduced as the containment period increased. Conclusions Suppression success hinges on a balance between the environmental factors that drive fire spread and the rapid deployment of sufficient resources to limit fire perimeter growth. Implications Decreasing the period between an ignition and the time of arrival at the fire will allow first responders to begin suppression before the fire size has exceeded their capability to construct a control line.
... Most suppression tactics are undertaken to contain the spread of a fire and keep it from escaping containment. The aim is to stop fire spread either directly through action at the fire edge or indirectly through the manipulation of fuels ahead of a fire (Plucinski 2019b;Simpson et al. 2019). Direct attack actions may involve the application of water or water with additives onto burning fuels or the removal of unburnt fuels adjacent to burning fuels. ...
... Recently, Simpson et al. (2019) have proposed a conceptual map of "suppression" based on 20 distinct suppression tasks, resulting from operational activities which can be classified into five stages: 1) defensive suppression occurs when the fire behaviour exceeds the control capability of suppression resources; 2) offensive suppression refers to the stage when the suppression resources make 'gains' on the fire and plans are emerging and carried out; 3) containment achieved occurs when mop-up activities can keep the fire at a control line established over the sector; 4) the mop-up stage occurs after completing the mop-up of some depth (usually a 30 m perimeter); 5) patrol and rehabilitation refer to the stage when the fire is still burning inside the perimeter or in isolated hotspots, mop-up is nearly complete, and resources can be recovered. ...
... According to Simpson et al. (2019), annual wildfire operations costs in Australia (US$ 217 M in 2016 and US$ 268 M in 2017) exceeded the overall suppression expenses (US$ 208 million) during the 2003 fire season, which was one of the most severe seasons on record. Indeed, the majority of fire suppression expenses are involved in the suppression of large wildfires. ...
The cost of suppressing fires is known to be highly significant and increasing over time as a result of the indirect effects of climate change and rising human impacts. Their quantification is an essential component of an environmental accounting system, capable of providing updated information for policy design and implementation. The goal of this study was to provide an overview of the state-of-art of international literature on wildfire suppression costs. To this aim, a systematic literature review was carried out revealing that the largest amount of empirical data on suppression costs and related measures derived from North American case studies. Conversely, information on direct wildfire suppression cost categories is usually incomplete or missing throughout Europe, especially in fire-prone Mediterranean countries, even though these areas have been, and continue to be, severely impacted by wildfires, underlining the need to update research in this field, thereby supporting cost-effective fire management plans.
... Most suppression tactics are undertaken to contain the spread of a fire and keep it from escaping containment. The aim is to stop fire spread either directly through action at the fire edge or indirectly through the manipulation of fuels ahead of a fire (Plucinski 2019b;Simpson et al. 2019). Direct attack actions may involve the application of water or water with additives onto burning fuels or the removal of unburnt fuels adjacent to burning fuels. ...
... Forest roads can also alter spatial patterns of ignitions, as well as modify and limit fire boundaries. Roads can function as supplementary firebreaks supporting safer and more effective wildfire management (Katuwal et al., 2016;Narayanaraj and Wimberly, 2012;Simpson et al., 2019;Yocom et al., 2019). Therefore the distance between any point in the forest and the nearest public road (excluding motorways and expressways) or a forest road functioning as fire access should not exceed 0.75 km or 1.50 km, depending on the assumed fire hazard category of the forest (the National Law and internal regulations of the State Forests). ...
Climate change observed in recent years has led to a rise in the frequency and magnitude of meteorological phenomena such as violent storms, intense rainfall or heat events, which have triggered floods, mass land movement, droughts, and wildfire. The intensification of severe weather conditions has put a strain on forest stand regions in Europe. Weather-related stressors are considered the leading factor in the degradation of forest stands and the growing susceptibility of trees to pathogenic agents. The new dynamic situation has substantially altered the external conditions of forest management in Poland. Long-established management methods have had to be revised, and new approaches developed to face the emerging or aggravated threats to forests. It has become apparent in many cases that sole silvicultural techniques will not be sufficiently effective and should be supported or supplemented by technical solutions to respond adequately. We discuss our research and findings in the domain of engineering solutions applied in forests to optimise the road network, limit the effects of natural hazards, implement hydrological restoration, alter water storage and assess the impact of engineering infrastructure on the environment. The article presents the management of natural hazards and adopted engineering approaches from a Polish perspective. Case studies of applied solutions to prevent and limit the damaging effects of natural hazards and disasters on forests are included. Climate change observed in recent years has led to a rise in the frequency and magnitude of meteorological phenomena such as violent storms, intense rainfall or extreme heat events, which have triggered floods, mass land movements, droughts and wildfires. The intensification of severe weather conditions has put a strain on forest stands in many regions of Europe. Weather-related stressors are considered a leading factor in the degradation of forest stands and the growing susceptibility of trees to pathogenic agents. The new dynamic situation has substantially altered conditions for forest management in Poland. Long-established management methods have had to be revised, while new approaches need to be developed to face the emerging or aggravated threats to forests. It has become apparent in many cases that silvicultural techniques alone will not be sufficiently effective and thus should be supported or supplemented by technical solutions to respond adequately to the altered conditions. This study and the obtained findings are discussed in terms of engineering solutions applied in forests to optimise the road network, limit the effects of natural hazards, implement hydrological restoration and enhance water storage. The article presents management of natural hazards and adopted engineering approaches from a Polish perspective. Case studies of applied solutions to prevent and limit the damaging effects of natural hazards and disasters on forests are included.
... In a previous suppression analysis, we identified suppression firing on 6 of a subset of 10 of these fires [31]. We used our previous study as a pilot to establish that (1) suppression firing could be identified by examining comments in the SitReps and (2) that suppression firing often occurred along existing roads. ...
Fire management agencies around the world use suppression firing for fire control. Yet, we know little about the extent of its use (e.g., prevalence and spatial coverage) and its impact on containment. We examine the prevalence and practice of suppression firing in Victoria, Australia. We used operational data from five years (2010–2015) to identify and map the incidence of suppression firing on 74 large fires (500+ ha). Suppression firing occurred on half (34) of these fires, 26 of which had data to map firing locations. The area burnt by suppression firing ranged from <1 ha to ~20,000 ha on separate fires. Archetypal suppression firing occurred during intervals of low fire spread and resulted in modest fire behaviour. Ground crews generally conducted the perimeter suppression firing. Aerial ignition was more common on large internal firing operations. For the 26 fires where we mapped the firing locations, firing occurred along 77% of the perimeter-aligned road. Suppression firing was a prominent containment tool used along one-fifth of the total external perimeter of these 74 large fires. Quantification of this practice is a first step towards establishing ignition thresholds, production rates, and integration with containment probability models.
... ROS predictions are a critical part of the information used (along with field observations, weather forecasts, etc.) to make operational decisions around what firefighting strategies to use (e.g. offensive or defensive; Simpson et al., 2019), where to concentrate firefighting efforts (e.g. near a town that could be overrun within an hour) and when community warnings and evacuation alerts should be sent (AEMC and AEMC, 2009;Alexander and Cruz, 2013;Anderson-Berry et al., 2018). ...
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.
