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Prescribed burning is a key management strategy within fire-adapted systems, and improved monitoring approaches are needed to evaluate its effectiveness in achieving social-ecological outcomes. Remote sensing provides opportunities to analyse the impacts of prescribed burning, yet a comprehensive understanding of the applications of remote sensing for prescribed burn research is lacking. We conduct a literature review of 120 peer-reviewed publications to synthesise the research aims, methodologies, limitations and future directions of remote sensing for the analysis of prescribed fire. Studies evaluating management outcomes found prescribed burning effective for wildfire risk reduction, yet few analysed co-benefits or trade-offs with other management goals. Most studies use passive, spaceborne, low spatial resolution sensors, characterised in the literature as consistent and accessible data sources but limited in detecting small, low-severity and short-duration fires characteristic of prescribed burns. In contrast, active remote sensing approaches including LiDAR are less frequently employed, but show promise for highly accurate, spatially explicit 3D vegetation and fuel load mapping. Remote sensing advances toward higher spatial resolution, more frequent revisit, denser spectral sampling and more data across the electromagnetic spectrum are critical to advancing prescribed fire research, addressing current methodological gaps, and improving fuels and fire management capacity. Remote sensing is frequently used in fire ecology and management, but its applications for prescribed burning are not well established. We review studies that use remote sensing for prescribed burn research, finding that wildfire remote sensing approaches are not optimised for small, short-duration and low-severity burns typical of prescribed fire. [ABSTRACT FROM AUTHOR]

Global environmental and social change are pushing wildfire activity and impact beyond known trajectories. Here, we conducted a targeted review to distill five wildfire challenges that we argue form opportunities for their governance (research aim 1). We exemplified our arguments by drawing from the case of Cyprus (research aim 2), a small island country in the south-east European Mediterranean Basin at risk of extreme wildfire impact. Findings indicate that burning for social and ecological resource benefits, innovative management paradigms and anticipatory governance systems offer actionable solutions to the wildfire paradox and the limits of suppression. Local adaptive institutions and a reconceptualisation of wildfire as a risk and process beyond technocratic interpretations are necessary to account for broader social conditions shaping wildfire regimes and community impact. Governance systems that accommodate collective action have proven suitable to address multiple wildfire complexities linked with different socio-economic systems and values. A systematic literature review, policy review, and qualitative data collection on wildfire management in Cyprus track back to the initial framing. Our case study offers insights for tackling wildfires with actionable steps through overarching governance systems, and illustrates the potential for change in thinking of and acting on wildfire in flammable landscapes globally. Global change is pushing fire activity and impact beyond known trajectories. We reviewed the literature to bring forward five themes of attention for governance systems. The initial framing was then applied to the case of Cyprus, to exemplify the potential and urgency for change in wildfire thinking and action globally. [ABSTRACT FROM AUTHOR]

Background: Near-term forecasts of fire danger based on predicted surface weather and fuel dryness are widely used to support the decisions of wildfire managers. The incorporation of synoptic-scale upper-air patterns into predictive models may provide additional value in operational forecasting. Aims: In this study, we assess the impact of synoptic-scale upper-air patterns on the occurrence of large wildfires and widespread fire outbreaks in the US Pacific Northwest. Additionally, we examine how discrete upper-air map types can augment subregional models of wildfire risk. Methods: We assess the statistical relationship between synoptic map types, surface weather and wildfire occurrence. Additionally, we compare subregional fire danger models to identify the predictive value contributed by upper-air map types. Key results: We find that these map types explain variation in wildfire occurrence not captured by fire danger indices based on surface weather alone, with specific map types associated with significantly higher expected daily ignition counts in half of the subregions. Conclusions: We observe that incorporating upper-air map types enhances the explanatory power of subregional fire danger models. Implications: Our approach provides value to operational wildfire management and provides a template for how these methods may be implemented in other regions. This study assesses the predictive value of synoptic-scale upper-air map types in near-term fire weather forecasting in the US Pacific Northwest. A set of 13 patterns of 500-hPa geopotential heights are associated with spatially heterogeneous variation in wildfire activity within the region. [ABSTRACT FROM AUTHOR]

Background: To effectively reduce future wildfire risk, several management strategies must be evaluated under plausible future scenarios, requiring models that provide estimates of how likely wildfires are to spread to community assets (wildfire likelihood) in a computationally efficient manner. Approaches to quantifying wildfire likelihood using fire simulation models cannot practically achieve this because they are too computationally expensive. Aim: This study aimed to develop an approach for quantifying wildfire likelihood that is both computationally efficient and able to consider contagious and directionally specific fire behaviour properties across multiple spatial 'neighbourhood' scales. Methods: A novel, computationally efficient index for quantifying wildfire likelihood is proposed. This index is evaluated against historical and simulated data on a case study in South Australia. Key results: The neighbourhood index explains historical burnt areas and closely replicates patterns in burn probability calculated using landscape fire simulation (ρ = 0.83), while requiring 99.7% less computational time than the simulation-based model. Conclusions: The neighbourhood index represents patterns in wildfire likelihood similar to those represented in burn probability, with a much-reduced computational time. Implications: By using the index alongside existing approaches, managers can better explore problems involving many evaluations of wildfire likelihood, thereby improving planning processes and reducing future wildfire risks. Wildfire likelihood is quantified in a computationally efficient manner using a multi-scale 'neighbourhood index'. This is achieved by aggregating fire behaviour properties across multiple neighbourhood scales. The index is much more computationally efficient than alternative approaches and considers contagious and directionally specific fire behaviour properties across multiple spatial 'neighbourhood' scales. This article belongs to the Collection Fire & Climate. [ABSTRACT FROM AUTHOR]

Background: Wildfires have caused significant damage in Chile, with critical infrastructure being vulnerable to extreme wildfires. Aim: This work describes a methodology for estimating wildfire risk that was applied to an electrical substation in the wildland–urban interface (WUI) of Valparaíso, Chile. Methods: Wildfire risk is defined as the product between the probability of a wildfire reaching infrastructure at the WUI and its consequences or impacts. The former is determined with event trees combined with modelled burn probability. Wildfire consequence is considered as the ignition probability of a proxy fuel within the substation, as a function of the incident heat flux using a probit expression derived from experimental data. The heat flux is estimated using modelled fire intensity and geometry and a corresponding view factor from an assumed solid flame. Key results: The probability of normal and extreme fires reaching the WUI is of the order of 10−4 and 10−6 events/year, respectively. Total wildfire risk is of the order of 10−5 to 10−4 events/year Conclusions: This methodology offers a comprehensive interpretation of wildfire risk that considers both wildfire likelihood and consequences. Implications: The methodology is an interesting tool for quantitatively assessing wildfire risk of critical infrastructure and risk mitigation measures. A methodology offering a comprehensive interpretation of wildfire risk considering both wildfire likelihood and asset vulnerability is proposed. The former is estimated with an event tree, while the latter is considered as the ignition probability of a polymeric fuel within a critical infrastructure. Wildfire risk is ~10−4 events/year. This article belongs to the Collection ICFFR. [ABSTRACT FROM AUTHOR]

Background: Wildfires can have detrimental impacts on the environment and urban structures when they spread from wildland areas. Aims: In this work, a numerical study was performed to investigate the effect of downslope terrain on fire-induced flows in the presence of a building structure. Fires with intensities of 4 and 15 MW m−1 were considered on inclined terrain with downslope angles varying from 0° to −30°, and wind speeds of 6 and 12 m s−1. Methods: Simulations were conducted using a large eddy simulation (LES) solver, implemented in the open-source platform FireFOAM. Key results: The results were validated with experimental measurements of a full-scale building model. Results show that at a wind velocity of 12 m s−1, structures on steeper downslope terrains are at higher risk of wildfire damage, whereas at a constant wind velocity of 6 m s−1, these structures are at a lower risk. Conclusions: The outcomes of the study highlight the physical effect of sloped terrain on buildings downwind of a line fire. Implications: The results from this study can be used to evaluate the validity of risk management measures including building standards and asset protection zones and can better inform ways of improving these measures. Numerical simulations were used to investigate the impacts of wind, fire intensity and downslope inclination interactions on the heat exposure of an idealised building structure. At higher wind speeds, buildings on steeper downslopes were at higher risk of wildfire impacts. These results are at odds with current Australian building standards. [ABSTRACT FROM AUTHOR]

Background. Dead fuel moisture content (DFMC) is crucial for quantifying fire danger, fire behaviour, fuel consumption, and smoke production. Several previous studies estimating DFMC employed robust process-based models. However, these models can involve extensive computational time to process long time-series data with multiple iterations, and are not always practical at larger spatial scales. Aims. Our aim was to provide a more time-efficient method to run a previously established process-based model and apply it to Pinus yunnanensis forests in southwest China. Methods. We first determined the minimum processing time the process-based model required to estimate DFMC with a range of initial DFMC values. Then a long time series process was divided into parallel tasks. Finally, we estimated 1-h DFMC (verified with field-based observations) at regional scales using minimum required meteorological time-series data. Key results. The results show that the calibration time and validation time of the model-in-parallel are 1.3 and 0.3% of the original model, respectively. The model-in-parallel can be generalised on regional scales, and its estimated 1-h DFMC agreed well with field-based measurements. Conclusions. Our findings indicate that our model-in-parallel is time-efficient and its application in regional areas is promising. Implications. Our practical model-in-parallel may contribute to improving wildfire risk assessment. [ABSTRACT FROM AUTHOR]

Background. Wildfire spread is influenced significantly by the weather variability. Wind speed and direction changes, resulting from synoptic weather systems and small-scale meteorological processes in complex terrain, can drastically alter fire intensity and spread. Aims. To investigate the use of vector wind change (VWC) integrated with the Fire Weather Index (FWI) as a new metric in fire danger. Methods. A 20-year FWI and modified FWI was calculated from weather station and gridded numerical weather simulation data. Key results. High VWC is found primarily on the South Island, inland and in areas of complex terrain. After incorporating VWC into the FWI, data from the modified FWI show spatiotemporal patterns that highlight the impact of wind variability in the fire danger. Conclusions. High VWC station data mapped with synoptic type suggest the primary factor in determining high VWC is meso- and micro-scale terrain-driven meteorology, not larger synoptic regimes. Implications. The current fire danger metric, the Fire Weather Index (FWI), does not include wind direction changes for high wind speeds. Therefore, the inclusion of VWC as an additional metric in fire danger calculations in a modified FWI could increase operational understanding of high-danger locations and terrain impacts on extreme and unpredictable fire behaviour. [ABSTRACT FROM AUTHOR]

Background: Live fuel moisture content (LFMC) is a key environmental indicator used to monitor for high wildfire risk conditions. Many statistical models have been proposed to predict LFMC from remotely sensed data; however, almost all these estimate current LFMC (nowcasting models). Accurate modelling of LFMC in advance (projection models) would provide wildfire managers with more timely information for assessing and preparing for wildfire risk. Aims: The aim of this study was to investigate the potential for deep learning models to predict LFMC across the continental United States 3 months in advance. Method: Temporal convolutional networks were trained and evaluated using a large database of field measured samples, as well as year-long time series of MODerate resolution Imaging Spectroradiometer (MODIS) reflectance data and Parameter-elevation Relationships on Independent Slopes Model (PRISM) meteorological data. Key results: The proposed 3-month projection model achieved an accuracy (root mean squared error (RMSE) 27.52%; R 2 0.47) close to that of the nowcasting model (RMSE 26.52%; R 2 0.51). Conclusions: The study is the first to predict LFMC with a 3-month lead-time, demonstrating the potential for deep learning models to make reliable LFMC projections. Implications: These findings are beneficial for wildfire management and risk assessment, showing proof-of-concept for providing advance information useful to help mitigate the effect of catastrophic wildfires. We have proposed a deep learning model that makes advance predictions of fuel (vegetation) moisture content, a major driver of wildfire ignition and propagation. This proof-of-concept model produces accurate predictions with a 3-month lead time, demonstrating a potentially useful addition to wildfire management tools, facilitating early warning of high wildfire risk. [ABSTRACT FROM AUTHOR]

Background: This paper identifies the weaknesses of the Portuguese approach to promote wildfire risk reduction through spatial planning. Aims: This paper contributes to bridging a critical gap in knowledge on the role of spatial planning in the reduction of wildfire hazard, given that the characteristics of fire hazard are distinctive from other natural hazards. Methods: Firstly, we used an online questionnaire answered by 175 municipalities of Portugal in order to examine local technicians' experience in applying spatial planning legislation and wildfire management policies. In a second step, we collected data from a Delphi survey with 27 experts with the aim of confirming or repudiating the importance of each need for integration between spatial planning and rural fire management indicated by the replies of the 175 municipalities. Key results, conclusions, and implications: One of the main identified weaknesses relates to the integration of the National Hazard Map in the Constraints Map of the Master Plans, considering the high inter-annual variability of fire hazard and the long-term definition of the municipal spatial planning framework. Focused on the Portuguese wildfire management approach, this paper contributes to bridging a critical gap in knowledge on the role of spatial planning in the reduction of wildfire hazard, given that the characteristics of fire hazard are distinctive from other natural hazards (e.g. floods, costal erosion, earthquakes). (This paper is part of a Special Issue that includes papers on research presented at the IX International Conference on Forest Fire Research, Coimbra, Portugal, November 2022.) [ABSTRACT FROM AUTHOR]

Managing wildfire risk across boundaries and scales is critical in fire-prone landscapes around the world, as a variety of actors undertake mitigation and response activities according to jurisdictional, conceptual and administrative boundaries, based on available human, organisational, technical and financial resources. There is a need to catalyse coordination more effectively to collectively manage wildfire risk. We interviewed 102 people across five large landscape case studies in the western United States to categorise how people and organisations were deployed in range and forestlands to collectively address wildfire risk. Across all cases, actors spanned boundaries to perform functions including: (1) convening meetings and agreements; (2) implementing projects; (3) community outreach; (4) funding support; (5) project planning; (6) scientific expertise. These functions fostered conducive boundary settings, concepts and objects to communicate and work across boundaries, navigating challenges to implementing work on the ground. This work highlights context-specific ways to advance cross-boundary wildfire risk reduction efforts and uses a boundary spanning lens to illustrate how collective action in wildfire management evolves in different settings. This research highlights prescribed fire as a gateway for future collective action on wildfire risk, including managing naturally ignited wildfires for resource benefits and improving coordination during wildfire suppression efforts. Actors must collectively manage wildfire risk across administrative, conceptual, organisational and other boundaries in fire-prone landscapes. We interviewed practitioners in five cases across the western United States, identifying how actors were engaging in collective action to address wildfire risk, organised through a typology of actor functions and boundary-spanning features. [ABSTRACT FROM AUTHOR]

Background: Prescribed burns have been increasingly utilised in forest management in the past few decades. However, their effectiveness in reducing the risk of destructive wildfires has been debated. The sandpile model of self-organised criticality, first proposed to model natural hazards, has been recently applied to wildfire research for describing a negative linear relationship between the logarithm of fire size, in area burned, and the logarithm of fire incidence number of that size. Aims: We demonstrate the applicability of the sandpile model to an understanding of wildfire incidence and its trend with interested factors, such as prescribed burns. Methods: We leverage the sandpile model to perform a series of simulations, along with comparisons to historical wildfire data in three American states: Florida, California, and Georgia. Key results: Both simulated and historical data indicate that increased prescribed burning is associated with lowered incidence of large wildfires. Conclusions: Our study justifies the application of the sandpile model to wildfire research and establishes a novel method for facilitating the investigation of potential risk factors of wildfires. Implications: The sandpile model may be utilised for the development of optimal strategies for prescribed burning. An R-script for sandpile model simulation is available for further wildfire investigation. The sandpile model uses accumulating sand grains to approximate net fuel deposition. When a collapse occurs, it spreads, simulating the spread of fire. Data from both a sandpile model simulation and an analysis of historical forest fire data suggest that prescribed burning reduces the risk of destructive wildfires. [ABSTRACT FROM AUTHOR]

Background. Fire used for agriculture has many benefits, but can cause wildfires if prevention activities are unsuccessful. Aims. The aim of this study was to examine fire permit use and safe burning practices by rural residents in the Edson Forest Area, Alberta, Canada. Methods. In total, 269 rural landowners completed a mail survey designed to identify how they use fire, their awareness of wildfire risk, fire experience, fire permit use and safe burning practices. Key results. Most respondents used fire on their property, and all were aware of the local wildfire risk, but there was little recognition that using fire for agricultural purposes contributes to wildfires in the area. Many respondents were taking steps to prevent a fire from escaping, but some used fire without obtaining a permit. Those who had seen a wildfire in the Edson Forest Area were more likely to take measures to prevent a wildfire from escaping, and more likely to apply for a fire permit. Conclusions. This research contributes to knowledge about rural landowners' fire use, wildfire prevention activities and fire permit use. Implications. Future research should confirm how wildfire experience affects fire permit use and safe use of fire by rural residents. [ABSTRACT FROM AUTHOR]

Wildfire occurrence and behaviour are difficult to predict locally for the next day. In the present work, we propose relying on fire spread simulations to provide a fire danger index representative of the potential for fire spread that includes not only weather but also surrounding vegetation and orography. This is achieved using an artificial neural network emulator called DeepFire, trained based on simulated fire sizes. To determine how relevant this index can be in the assessment of next-day fire danger, the application of DeepFire to fire danger mapping using actual weather forecasts is studied. DeepFire forecasts for 13 fairly large fires that occurred in Corsica are analysed and compared with corresponding forecasts using another fire danger index used in operational conditions, highlighting the differences in terms of precision and the expected results of such predictions. The weather forecasts from which the weather inputs of DeepFire are determined have high spatial resolution and high frequency, which also applies to the fire danger predictions. Additionally, input uncertainty is propagated through DeepFire, resulting in ensembles of emulated fire size. Several approaches are proposed to analyse the results and provide fire danger maps and ratings using this new simulation-based prediction system. [ABSTRACT FROM AUTHOR]

Risk management is a significant part of federal wildland fire management in the USA because policy encourages the use of fire to maintain and restore ecosystems while protecting life and property. In this study, patterns of wildfire risk were explored from operational relative risk assessments (RRA) completed by land managers on 5087 wildfires from 2010 to 2017 in every geographic area of the USA. The RRA is the formal risk assessment used by land managers to develop strategies on emerging wildfires when concerns and issues related to wildfire management are in real-time. Only 38% of these wildfires were rated as high risk and 28% had high ratings for values at risk. Large regional variations were evident, with the West Coast regions selecting high risk and the South-west and Eastern regions selecting low risk. There were finer-scale influences on perceived risk when summarised on a jurisdictional level. Finally, risk summarised by USA agencies showed that the National Park Service and USDA Forest Service selected high risk less frequently compared with other agencies. By illuminating patterns of risk, this research intends to stimulate examination of the social, cultural, and physiographic factors influencing conceptions of risk. Longer duration, federal wildland fires in the USA are commonly represented by low and moderate risk. Regional variations in wildfire risk are evident, with the West Coast using 'high' risk and the South-west and Eastern regions opting for 'low'. Federal agencies also present different risk patterns. Photograph by Dr Russell Parsons. [ABSTRACT FROM AUTHOR]

Fire use is increasingly recognised as a central component of integrated land management in fire-prone places. Historically, fire use has been commonplace in many places in Ireland, where field burning is an established practice with a long pedigree among upland farmers seeking to improving forage among other benefits. This practice has been subject to controversy as wildfires – a hazard often associated with upland burning practice – continue to gain public attention and concern. This research seeks to understand the practice of field burning from the viewpoint of practitioners themselves through focus groups with upland burners conducted in a variety of locations across Ireland. Discussions focused on the history of field burning, reasons for its use, and how knowledge of the techniques involved in burning has been passed down through generations. The narrative that emerges is that of a critical livelihood-supporting practice steeped in social and ecological value but threatened by stringent regulation and shifting public opinion. We suggest that one way to preserve this practice may be to establish more formal linkages between fire use practitioners and Ireland's fire services, public land managers and regulators to promote appropriate use of traditional fire within modern legal and best practice frameworks. Intergenerational field burning practices in Ireland are increasingly under threat from changing policy and public concerns about wildfire risk. We investigate how burning practices are conducted and how knowledge of this practice is preserved through focus groups with 60 Irish farmers before providing suggestions for future partnerships to overcome current challenges to fire use. [ABSTRACT FROM AUTHOR]

A significant amount of research has examined what motivates people living in fire-prone areas to mitigate their wildfire risk (i.e. engage in activities that reduce vulnerability and the effects of a wildfire on an individual's property). However, drawing overarching conclusions from this research is difficult because of the myriad of ways researchers have measured and analysed wildfire risk mitigation. Although recommendations exist for measuring risk-mitigation activities, no research to date has based these recommendations on an examination of how different operationalisations influence subsequent interpretations of homeowner preparedness. We addressed this gap by examining how the effects of demographics and contextual factors on preparedness differ across different ways of counting the amount of vegetation management completed. We also examined how different statistical approaches influence the results. We found that measuring vegetation management as the sum of activities completed is problematic and can obfuscate important relationships. For example, age is positively related to the proportion of applicable activities completed, but not the total number. We recommend assessing which items are applicable to respondents and constructing proportional measures rather than sums. We also recommend that, given the need for maintenance of vegetation, researchers use non-binary measures that allow respondents to indicate how much work they have undertaken towards each activity. Common measures of wildfire risk mitigation as the sum of activities 'completed' are problematic. Measuring mitigation as the proportion of relevant activities completed and allowing respondents to indicate the amount of work they have undertaken reveals more nuanced relationships between demographics and mitigation than the sum of activities completed. [ABSTRACT FROM AUTHOR]

National and regional preparedness level (PL) designations support decisions about wildfire risk management. Such decisions occur across the fire season and influence pre-positioning of resources in areas of greatest fire potential, recall of personnel from off-duty status, requests for back-up resources from other areas, responses to requests to share resources with other regions during fire events, and decisions about fuel treatment and risk reduction, such as prescribed burning. In this paper, we assess the association between PLs assigned at national and regional (Northwest) scales and a set of predictors including meteorological and climate variables, wildfire activity and the mobilisation and allocation levels of fire suppression resources. To better understand the implicit weighting applied to these factors in setting PLs, we discern the qualitative and quantitative factors associated with PL designations by statistical analysis of the historical record of PLs across a range of conditions. Our analysis constitutes an important step towards efforts to forecast PLs and to support the future projection and anticipation of firefighting resource demand, thereby aiding wildfire risk management, planning and preparedness. [ABSTRACT FROM AUTHOR]

This paper examines the relationship between local elections and wildfire. Using data of wildfires in Greek municipalities between 2000 and 2010, I estimate models comparing wildfire outcomes in local election years against nonelection years. I find that wildfire occurrence and burned area are systematically lower in the years around local elections. In municipalities where incumbents run for re-election, the decrease in wildfire occurrence is smaller in the years leading to elections, and larger in the years following local elections. There is some limited evidence that the likelihood of reelection influences wildfire outcomes around the time of local elections. The results suggest a relationship can exist between politics at the local level, wildfire occurrence and burned area. As political and economic considerations can be important in driving wildfire outcomes, assessing wildfire risk cannot take place separately from the prevailing political, economic and institutional environment. [ABSTRACT FROM AUTHOR]

Despite evident advances in knowledge and understanding concerning the application of prescribed burning for delivering benefits in wildfire control and a variety of sociocultural, economic and environmental outcomes, the practical application of prescribed burning in Australia is increasingly administratively and logistically complex, often controversial and climatically challenging. This series of papers does not address the merits or otherwise of prescribed burning – we accept the lessons from antiquity and recent history that the use of prescribed fire in contemporary Australia is essential for reducing, although not always being able to deliver on, wildfire risks and meeting a variety of societal and environmental needs. This special issue focuses on several fundamental adaptive management and monitoring questions: are we setting appropriate management targets? Can these targets and associated indicators be readily measured? Can we realistically deliver on those targets? And if so, what are the costs and/or trade-offs involved? The 10 solicited papers included here provide a sample illustration of the diversity of approaches currently being undertaken in different Australian regions to address complex adaptive management and monitoring challenges. This introduction to the special issue Adaptive prescribed burning in Australia for the early 21st Century provides an overview of the context, status and challenges for contemporary prescribed burning in Australia. We conclude that management targets for prescribed burning should address societal and environmental needs, be capable of measuring trends in performance and reinforce an adaptive management framework. [ABSTRACT FROM AUTHOR]

We present a method to quantify and map the probability of fires reaching the vicinity of assets in a wildfire-prone region, by extending a statistical fire spread model developed on historical fire patterns in the Sydney region, Australia. It calculates the mean probability of fire spreading along sample lines around assets, weights the probability according to ignition probability and also estimates the change in spread probability that fuel reduction in treatment blocks would achieve. We have developed an R package WildfireRisk to implement the analysis and demonstrate it with two case studies in forested eastern Australia. The probability of a fire reaching the vicinity of an asset was highest in the heavily forested parts of each case study, but when weighted for ignition probability, the high probability shifted to the wildland–urban interface. Further, when weighted by asset location, high-priority areas for treatment were in blocks next to the wildland–urban interface. This method is objective, fast and based on the behaviour of real historical fires. We recommend its use in wildfire risk planning, as an adjunct to heuristic methods and simulations. Additional functionality can be incorporated into our method, for instance via a function for building impact. We present a statistical method to quantify and map wildfire spread to assets and the reduction gained by removing fuel from treatment blocks based on fire spread patterns in historical fires. The likelihood of spread to assets was highest in areas with high forest cover, but spread reduction was highest in treatment blocks at the wildland–urban interface. [ABSTRACT FROM AUTHOR]

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. We use fire behaviour simulations and Bayesian networks to estimate the risk mitigation effects of prescribed burning for area burnt, house loss, life loss, length of powerline and road damaged, and area burnt below minimum tolerable fire interval. Our methods can be used to quantify and compare risk across regions. [ABSTRACT FROM AUTHOR]

This article analyses homeowners' decisions to undertake fire-safe investments and create defensible space on their property using a unique dataset from 35 wildland–urban interface communities in Nevada. The dataset combines homeowner information from a mail survey with their observed fire-safe investments obtained through parcel-level hazard assessments. We find that homeowners' self-reported mitigation expenditures are driven by their subjective beliefs about their wildfire risk, whereas observed defensible space status is driven by their costs of investment. We develop a theoretical model of a homeowner's fire-safe investment decision that accounts for our empirical results. This article uses a unique dataset from 35 wildland–urban interface communities in Nevada to analyse how a homeowner's decision to undertake a generic fire-safe investment is different than their decision to perform the suite of fire-safe investments necessary to create adequate defensible space on their property. [ABSTRACT FROM AUTHOR]

The wildland–urban interface (WUI) is a focal area for human environmental conflicts including wildfires. The WUI grows because new houses are built, and in developed countries, housing growth can be very rapid in areas with natural amenities. However, it is not clear if natural amenity-driven WUI growth is limited to developed countries, or also prevalent in developing countries. Amenity-driven WUI growth may be particularly rapid there, owing to a rapidly growing middle class. Our objectives were to (i) map the current WUI; (ii) quantify recent WUI growth; and (iii) analyse relationships between the WUI and both fire ignition points and wildfire perimeters in the region of El Bolson, in Central Andean Patagonia, Argentina. We mapped the current WUI based on housing information derived from census data, topographic maps, high-resolution imagery and land-cover data. We found that the WUI contained 96.6% of all buildings in 2016 even though the WUI covered only 6.4% of the study area. Between 1981 and 2016, the WUI increased in area by 76%, and the number of houses by 74%. Furthermore, 77% of the recent fires in the region occurred in the WUI, highlighting the need to balance development with wildfire risk and other human–environmental problems. We analysed wildland–urban interface (WUI) changes and wildfire occurrence in Patagonia, Argentina. Only 6.4% of the study area was considered as WUI, but contained 97% of the houses. Between 1981 and 2016, WUI increased by 76%, and from 2010 to 2015, 77% of the ignition points occurred within this WUI. [ABSTRACT FROM AUTHOR]

Leaf flammability is a multidimensional plant functional trait with emerging importance for wildfire risk management. Understanding relationships among leaf flammability attributes not only provides information about the properties of leaves as fuels in the wildland–urban interface (WUI), it can also offer an effective way to identify low-leaf-flammability species. We examined relationships between leaf ignitibility, sustainability and combustibility among 60 plant species of the WUI of eastern Australia. We found that leaf ignitibility and sustainability worked in opposition to each other as dimensions of flammability. Species with leaves that were slow to ignite were those with leaves that sustained burning for the longest, whereas species with leaves that were fast to ignite had leaves that burned for the shortest periods of time. Low leaf combustibility was related to short leaf burning sustainability but not to ignitibility. We created an overall leaf flammability index (OLFI) to rank species on emergent properties of ignitibility, sustainability and combustibility attributes in combination. We found that low-leaf-flammability species with low OLFI values had small leaf area, high leaf mass per area and high leaf water content. Our findings have implications for species selection for green firebreaks in the WUI. Analyses of relationships among flammability attributes showed that slow leaf ignitibility was correlated with long leaf burning sustainability, and vice versa. Low leaf combustibility was related to short leaf sustainability. Low overall leaf flammability was related to small leaf area, high leaf mass per area and high leaf water content. [ABSTRACT FROM AUTHOR]

Recent studies have highlighted the potential of linking fire behaviour to plant ecophysiology as an improved route to characterising severity, but research to date has been limited to laboratory-scale investigations. Fine-scale fire behaviour during prescribed fires has been identified as a strong predictor of post-fire tree recovery and growth, but most studies report these metrics averaged over the entire fire. Previous research has found inconsistent effects of low-intensity fire on mature Pinus ponderosa growth. In this study, fire behaviour was quantified at the tree scale and compared with post-fire radial growth and axial resin duct defences. Results show a clear dose-response relationship between peak fire radiative power per unit area (Wm-2) and post-fire Pinus ponderosa radial growth. Unlike in previous laboratory research on seedlings, there was no dose-response relationship observed between fire radiative energy per unit area (J m-2) and post-fire mature tree growth in the surviving trees. These results may suggest that post-fire impacts on growth of surviving seedlings and mature trees require other modes of heat transfer to impact plant canopies. This study demonstrates that increased resin duct defence is induced regardless of fire intensity, which may decrease Pinus ponderosa vulnerability to secondary mortality agents. [ABSTRACT FROM AUTHOR]

The research investigated understandings of risk and resilience in emergency management (EM) policy and practice. The core findings illustrate how a complex of institutionalised socio-cultural expectations and standardised processes - that is, evidence-based response models to deal with and communicate uncertainty - influence the operationalisation of resilience in EM. We observe that a focus on disaster risk as a quantifiable product of physical hazards is an attempt to control uncertainty and leads to engineered or technology-centred response solutions. Accordingly, community resilience is principally seen as the product of risk reduction, incident response and recovery interventions. The research shows that resultant command and control management practices produce limited - and limiting - interpretations of community resilience as disaster resilience. This can restrict existing and emergent community responses to risk, and the ability to imagine and enact more systemic types of community resilience. For instance, the short-term disaster focus tends to neglect the social and institutional root causes of community vulnerability and generic risk information is detached from everyday community experience. Using wildfire in Australia as its case study, this paper discusses the social, cultural and practical challenges of operationalising social-ecological resilience in EM. [ABSTRACT FROM AUTHOR]

Loss prediction models are an important part of wildfire risk assessment, but have received only limited attention in the scientific literature. Such models can support decision-making on preventive measures targeting fuels or potential ignition sources, on fire suppression, on mitigation of consequences and on effective allocation of funds. This paper presents a probabilistic model for predicting wildfire housing loss at the mesoscale (1 km2) using Bayesian network (BN) analysis. The BN enables the construction of an integrated model based on causal relationships among the influencing parameters jointly with the associated uncertainties. Input data and models are gathered from literature and expert knowledge to overcome the lack of housing loss data in the study area. Numerical investigations are carried out with spatiotemporal datasets for the Mediterranean island of Cyprus. The BN is coupled with a geographic information system (GIS) and the resulting estimated house damages for a given fire hazard are shown in maps. The BN model can be attached to a wildfire hazard model to determine wildfire risk in a spatially explicit manner. The developed model is specific to areas with house characteristics similar to those found in Cyprus, but the general methodology is transferable to any other area, as well as other damages. [ABSTRACT FROM AUTHOR]

Wildfires pose complex challenges to policymakers and fire agencies. Fuel break networks and area-wide fuel treatments are risk-management options to reduce losses from large fires. Two fuel management scenarios covering 3% of the fire-prone Algarve region of Portugal and differing in the intensity of treatment in 120-m wide fuel breaks were examined and compared with the no-treatment option. We used the minimum travel time algorithm to simulate the growth of 150 000 fires under the weather conditions historically associated with large fires. Fuel break passive effects on burn probability, area burned, fire size distribution and fire transmission among 20 municipalities were analysed. Treatments decreased large-fire incidence and reduced overall burnt area up to 17% and burn probability between 4% and 31%, depending on fire size class and treatment option. Risk transmission among municipalities varied with community. Although fire distribution shifted and large events were less frequent, mean treatment leverage was very low (1 : 26), revealing a very high cost-benefit ratio and the need for engaging forest owners to act in complementary area-wide fuel treatments. The study assessed the effectiveness of a mitigating solution in a complex socioecological system, contributing to a better-informed wildland fire risk governance process among stakeholders. [ABSTRACT FROM AUTHOR]

Measured soil moisture data may improve wildfire probability assessments because soil moisture is physically linked to fuel production and live fuel moisture, yet models characterising soil moisture-wildfire relationships have not been developed. We therefore described the relationships between measured soil moisture (concurrent and antecedent), as fraction of available water capacity (FAW), and large (≥405 ha) wildfire occurrence during the growing (May-October) and dormant (November-April) seasons from 2000 to 2012 in Oklahoma, USA. Wildfires were predominantly grass and brush fires but occurred across multiple fuel types including forests. Below-average FAW coincided with high wildfire occurrence each season. Wildfire probability during the growing season was 0.18 when concurrent FAW was 0.5 (a threshold for plant water stress) but was 0.60 when concurrent FAW was 0.2 (extreme drought). Dormant season wildfire probability was influenced not only by concurrent but also by antecedent FAW. Dormant season wildfire probability was 0.29 and 0.09 when FAW during the previous growing season was 0.9 (near ideal for plant growth) and 0.2, respectively. Therefore, although a wet growing season coincided with reduced wildfire probability that season, it also coincided with increased wildfire probability the following dormant season, suggesting that the mechanisms by which soil moisture influences wildfire probability are seasonally dependent. [ABSTRACT FROM AUTHOR]

Recent years have seen growing interest within the United States fire management community in exploring alternatives to the standard approach of evacuating entire populations that are threatened by a wildfire. There has been particular interest in what can be learned from the Australian approach, whereby residents choose whether or not to evacuate under the 'prepare, stay and defend or leave early' approach, also called Stay or Go. Given these developments, it is useful to understand what elements are taken into consideration by those who would be most affected by a new approach when they think through the pros and cons of mass evacuation v. an alternative strategy should a wildfire occur. This paper reports on findings from interviews in four communities in the United States where some alternative to mass evacuation during a wildfire was being considered. In each community, emergency responders and community members were asked for their perspective on the pros and cons of evacuation and the alternative being considered. The results show that opinions were mixed on whether evacuation or an alternative approach was more appropriate. Individuals who were primarily thinking of improving safety and reducing uncertainty for emergency responders tended to think mass evacuation was the best approach, whereas those who were primarily thinking of increasing safety and reducing uncertainty for homeowners were more likely to think that alternative responses were a valid option. These findings demonstrate the complicated nature of developing evacuation strategies that are beneficial to all parties involved. [ABSTRACT FROM AUTHOR]

This paper presents a new methodology for making strategic dozer deployment plans for wildfire initial response planning for a given fire season. This approach combines a fire behaviour simulation, a wildfire risk model and a probabilistically constrained stochastic integer programming model, and takes into account the level of risk the decision-maker is willing to take when making deployment and dispatching plans. The new methodology was applied to Texas District 12, a Texas A&M Forest Service fire planning unit located in East Texas. This study demonstrates the effect of the decision-maker's risk attitude level on deployment decisions in terms of the dozers positioned at each operations base, fires contained and their associated wildfire risk, and total containment cost. The results show that the total number of fires contained and their associated total expected cost increase when the tolerance towards risk decreases. Thus, more dozers are deployed to operations bases in areas with high wildfire risk and a high need for initial response. We consider a new methodology for making effective strategic deployment decisions for wildfire initial response planning. This methodology includes a fire behaviour simulation, a wildfire risk model, and a probabilistically constrained stochastic integer programming model. A study based on the District 12 in East Texas involving dozers is reported. [ABSTRACT FROM AUTHOR]

Traditional uses of the forest (timber, forage) have been giving way to other uses more in demand (recreation, ecosystem services). An observable consequence of this process of forest land use conversion is an increase in more difficult and extreme wildfires. Wildland forest management and protection program budgets are limited, and managers are requesting help in finding ways to objectively assign their limited protection resources based on the intrinsic environmental characteristics of a site and the site's interrelationship with available firefighting resources and existing infrastructure. A Fire Suppression Priority Index, integrating information on both the potential fire behaviour risk (Potential Fire Behaviour Index) and the fire suppression difficulty (Suppression Difficulty Index), provides managers with fundamental information for strategic planning and development of tactical operations to protect the natural environment. Results in the Córdoba Province, Andalusia's autonomous region, Spain, showed a statistically significant relationship between wildfire size and all three indices, demonstrating the utility of the methodology to identify and prioritise forest areas for strategic and tactical fire management operations. In addition, the methodology was tested and validated by trained and qualified wildfire management personnel in Chile and Israel, obtaining similar results as in Spain. [ABSTRACT FROM AUTHOR]

Policymakers seek ways to encourage fuel reduction among private forest landowners to augment similar efforts on federal and state lands. Motivating landowners to contribute to landscape-level wildfire protection requires an understanding of factors that underlie landowner behaviour regarding wildfire. We developed a conceptual framework describing landowners' propensity to conduct fuel reduction as a function of objective and subjective factors relating to wildfire risk. We tested our conceptual framework using probit analysis of empirical data from a survey of non-industrial private forest landowners in the ponderosa pine (Pinus ponderosa) region of eastern Oregon (USA). Our empirical results confirm the conceptual framework and suggest that landowners' perceptions of wildfire risk and propensity to conduct fuel treatments are correlated with hazardous fuel conditions on or near their parcels, whether they have housing or timber assets at risk, and their past experience with wildfire, financial capacity for conducting treatments and membership in forestry and fire protection organisations. Our results suggest that policies that increase awareness of hazardous fuel conditions on their property and potential for losses in residential and timber assets, and that enhance social networks through which awareness and risk perception are formed, could help to encourage fuel reduction among private forest landowners. [ABSTRACT FROM AUTHOR]

Abstract. Fire-prone shrub-dominated vegetation communities cover a considerable portion of Australia, including areas fringing urban development. Near urban interfaces, they are actively managed with prescribed fire to reduce the risk of wildfire (unplanned fire). Knowledge of the range of conditions that allow fires to spread or fail to do so is limited and can inconvenience fire managers when conducting prescribed burns. A series of experimental ignitions conducted in miniature shrublands reconstructed in the laboratory were used to investigate factors that influence ignition thresholds. The miniature shrublands were composed of foliage from the shrub Allocasuarina nana and were prepared over a range of moisture contents and densities. The impact of dead fuel within the aerial structure of the shrubs was also investigated, as was the presence and absence of wind and litter. The most important factors for spread initiation were identified using logistic regression analysis and classification tree modelling. The presence of litter, live fuel moisture content, shrub-layer density, presence of wind, and the amount and continuity of the dead elevated fuel were all found to influence spread sustainability. There was a negative interaction between shrub-layer density and live fuel moisture content, showing the effect of density to be less at higher moisture contents. [ABSTRACT FROM AUTHOR]

Abstract. On the morning of 2 June 2002, an abandoned campfire grew into a wildfire in the DoubleTroublc State Park in cast-central New Jersey, USA. The wildfire burned 526 ha (1300 acres) and forced the closure of the Garden State Parkway for several hours due to dense smoke. In addition to the presence of dead and dry fuels due to a late spring frost prior to the wildfire, the meteorological conditions at the time of the wildfire were conducive to erratic fire behaviour and rapid fire growth. Observations indicate the occurrence of a substantial drop in relative humidity at the surface accompanied by an increase in wind speed in the vicinity of the wildfire during the late morning and early afternoon of2 June. The surface drying and increase in wind speed are hypothcsised to result from the downward transport of dry, high-momentum air from the middle troposphere occurring in conjunction with a deepening mixed layer. This hypothesis is addressed using a high-resolution mesoscalc model simulation to document the structure and evolution of the planetary boundary layer and lower-tropospheric features associated with the arrival of dry, high-momentum air at the surface coincident with the sudden and dramatic growth of the wildfire. [ABSTRACT FROM AUTHOR]

One of the thorniest challenges to effective wildland fire management is integration of public perceptions and values into science-based adaptive management. One promising alternative is incorporation of public values into place-based decision support technologies that are accessible to lay citizens as well as to fire-management experts. A survey of individuals, including residents, fire and fuels managers, volunteer firefighters, and others living in or near four mountain areas of the US Southwest, identified a set of personal values and perceptions about wildland fire risk that could be spatially represented in a geographic information science-based decision support system designed for wildland fire strategic planning efforts. We define values, in this context, as phenomena that are not necessarily quantifiable but that strongly attract and connect individuals for whatever reasons to particular areas. Inclusion of this type of information into interactive decision tools for fire management may contribute to improved understanding and finer-scale spatial visualisation of public perceptions of fire risk. The integration of such factors in decision support tools offers opportunities for improving interactions between managers and the public involved in strategic planning processes for fire management. [ABSTRACT FROM AUTHOR]

The Hawaiian Islands experience damaging wildfires on a yearly basis. Soil moisture or lack thereof influences the amount and flammability of vegetation. Incorporating daily maximum temperatures and daily rainfall amounts, the Keetch-Byram Drought Index (KBDI) estimates the amount of soil moisture by tracking daily maximum temperatures and rainfall. A previous study found a strong link between the KBDI and total area burned on the four main Hawaiian Islands. The present paper further examines the natural variability of the KBDI. The times of year at which the KBDI is highest, representing the highest fire danger, are found at each of the 27 stations on the island chain. Spectral analysis is applied to investigate the variability of the KBDI on longer time scales. Windward and leeward stations are shown to have different sensitivities to large-scale climatic fluctuations. An El Niño signal displays a strong relationship with leeward stations, when examined with a band-pass filter and with a composite of standardized anomalies. Departure patterns of atmospheric circulations and sea surface temperatures over the North Pacific are investigated for composites of extremely high KBDI values when fire risk is high. The winter, spring, and fall show anomalous surface anticyclonic circulations, surface divergence, and subsidence over the islands for the upper quartile of KBDI. The winter, spring, and fall composites of equatorial sea surface temperatures for the upper quartile of KBDI are investigated for possible links to atmospheric circulations. These analyses are an effort to allow fire managers some lead time in predicting future fire risks. [ABSTRACT FROM AUTHOR]

HIGRAD/FIRETEC is a coupled atmosphere/wildfire behavior model based on conservation of mass, momentum, species, and energy. It combines a three-dimensional transport model that uses a compressible-gas fluid dynamics formulation with a physics-based wildfire model, to represent the coupled behavior of the local atmosphere and wildfire. In its current formulation, combustion and pyrolysis are treated as a single process, which depends on the local densities of wood and oxygen, the levels of turbulent mixing, and a probability distribution function (PDF) for temperature in the solid. The PDF is employed to estimate the volume fraction that is hot enough to burn. This burning model is now being extended to deal with pyrolysis and combustion as separate processes. Some fire behaviors, such as flash events, crowning, and fire `whirls', may depend on the ability of combustion to take place in a separate spatial location from the pyrolysis. We refer to this burning model as `non-local'. In the non-local burning model, pyrolysis is dealt with in roughly the same way as formerly, but now as an endothermic process. Instead of producing solely inert gasses, it now produces a mixture of inert and combustible gasses. Combustion is handled as a separate gas-gas reaction, which is highly exothermic. The basic premise of the HIGRAD/FIRETEC burning model is retained, i.e. that the rate of a reaction is limited by the rate at which the reactants can be brought together (mixing limited). In the non-local burning model, the reactants for pyrolysis can be thought of as heat and wood, for combustion: the reactive gas and oxygen. A few simple test cases that used idealised geometries were simulated with both burning models, and the results were compared. The non-local burning model was found to give results comparable to the local burning model in terms of the fire-line shape and the spread rate for these simple test cases. [ABSTRACT FROM AUTHOR]

Formulation of a physics-based model, capable of predicting fire spread through a single elevated crown-like shrub, is described in detail. Predictions from the model, obtained by numerical solutions to governing equations of fluid dynamics, combustion, heat transfer and thermal degradation of solid fuel, are found to be in fairly good agreement with experimental results. In this study we utilise the physics-based model to explore the importance of two parameters - the spatial variation of solid fuel bulk density and the solid fuel moisture content - on the burning of an isolated shrub in quiescent atmosphere. The results suggest that vertical fire spread rate within an isolated shrub and the time to initiate ignition within the crown are two global parameters significantly affected when the spatial variation of the bulk density or the variation of fuel moisture content is taken into account. The amount of fuel burnt is another parameter affected by varying fuel moisture content, especially in the cases of fire propagating through solid fuel with moisture content exceeding 40%. The specific mechanisms responsible for the reduction in propagation speed in the presence of higher bulk densities and moisture content are identified. Formulation of a physics-based model capable of predicting the spread of laboratory-scale fires is described. The model is used to investigate the importance of spatial distribution of bulk density, and of moisture content on the fire spread within a shrub. [ABSTRACT FROM AUTHOR]