Forest fire risk assessment plays a crucial role in the environmental management of natural hazards, serving as a key tool in the prevention of forest fires and the protection of various species. As these risks continue to evolve with environmental changes, the pertinence of contemporary research in this field remains undiminished. This review constructs a comprehensive taxonomic framework for classifying the existing body of literature on forest fire risk assessment within forestry studies. The developed taxonomy categorizes existing studies into 8 primary categories and 23 subcategories, offering a structured perspective on the methodologies and focus areas prevalent in the domain. We categorize a sample of 170 articles to present recent trends and identify research gaps in forest fire risk assessment literature. The classification facilitates a critical evaluation of the current research landscape, identifying areas in need of further exploration. Particularly, our review identifies underrepresented methodologies such as optimization modeling and some advanced machine learning techniques, which present routes for future inquiry. Moreover, the review underscores the necessity for model development that is tailored to specific regional data sets but also adaptable to global data resources, striking a balance between local specificity and broad applicability. Emphasizing the dynamic nature of forest fire behavior, we advocate for models that integrate the burgeoning field of machine learning and multi-criteria decision analysis to refine predictive accuracy and operational effectiveness in fire risk assessment. This study highlights the great potential for new ideas in modeling techniques and emphasizes the need for increased collaboration among research communities to improve the effectiveness of assessing forest fire risks.

Living with wildfires in an era of climate change requires adaptation and weaving together many forms of knowledge. Empirical evidence of knowledge co-production in wildfire management is lacking in Mediterranean European areas. We explored how local ecological knowledge can be leveraged to reduce wildfire risk through an adaptation pathways process in the Montseny massif and wider Tordera River watershed of Catalonia, Spain: an area stewarded through forestry and agriculture, tourism, nature conservation, and fire management. We combined different methods (e.g., a timeline and Three Horizons framework) throughout three workshops with agents of change to co-create adaptation pathways to reduce wildfire risk, integrating a historical perspective of the landscape while envisioning desirable futures. Our results showed that local ecological knowledge and other soft adaptation strategies contribute to innovative sustainable development initiatives that can also mitigate wildfire risk. The adaptation pathways approach holds much potential to inform local policies and support wildfire-based community initiatives in diverse contexts.

Emissions from wildfires worsen air quality and can adversely impact human health. This study utilized the fire inventory from NCAR (FINN) as wildfire emissions, and performed air quality modeling of April-October 2012, 2013, and 2014 using the U.S. Environmental Protection Agency CMAQ model under two cases: with and without wildfire emissions. This study then assessed the health impacts and economic values attributable to PM2.5 from fires. Results indicated that wildfires could lead annually to 4000 cases of premature mortality in the U.S., corresponding to $36 billion losses. Regions with high concentrations of fire-induced PM2.5 were in the west (e.g., Idaho, Montana, and northern California) and Southeast (e.g., Alabama, Georgia). Metropolitan areas located near fire sources, exhibited large health burdens, such as Los Angeles (119 premature deaths, corresponding to $1.07 billion), Atlanta (76, $0.69 billion), and Houston (65, $0.58 billion). Regions in the downwind of western fires, although experiencing relatively low values of fire-induced PM2.5, showed notable health burdens due to their large population, such as metropolitan areas of New York (86, $0.78 billion), Chicago (60, $0.54 billion), and Pittsburgh (32, $0.29 billion). Results suggest that impacts from wildfires are substantial, and to mitigate these impacts, better forest management and more resilient infrastructure would be needed.

Utilizing a unique database of residential real estate transactions, we examine the price change near the boundary of the Bushfire Prone Area (BPA), a planning zone indicating high wildfire risk, after experiencing a salient wildfire event in Australia from 2015 to 2016. While the properties within the BPA are valued more by 1.6%-1.9% in general, home buyers pay less for the properties in the BPA by 0.9%-1.7% after experiencing a salient wildfire event compared with the properties located outside of the BPA. Moreover, the properties in the BPA with greater environmental amenities are more resilient to the impact of wildfire risk salience than the rest BPA, necessitating an analysis of the role of environmental amenities in the research on wildfire risk in the housing market context.

This study aimed at delineating the wildfire risk zones in a fire-prone region located in a rarely addressed area of western Iran (Paveh city) by assessing the potential of factors such as NDVI, topographic factors (elevation, slope, and aspect), land cover, and evaporation in explaining the fire occurrence probability. Analytic hierarchy process (AHP) and geographical information system (GIS) methods were used synergistically to integrate the mentioned factors into analysis, following an informed categorization of each factor based on the information on previous fire occurrence. In the AHP process, elevation and evaporation data were considered to be the most critical factors. It was found that the predicted wildfire risk areas were in agreement with past fire events by the use of the methodology proposed by this study. Accordingly, the study\'s final wildfire risk map indicated that approximately 64.7% of the study area is located in the high- and very high-risk zones. Land-use planners and decision-makers may use the developed map to setup and implement fire prevention strategies and enhance or develop the fire-surveillance logistics and infrastructure, including but not limited to the positions of fire watchtowers, fire lines, and fire sensors, with the aim to minimize potential fire impacts.

The spatial and temporal behavior of the occurrence of forest fires in Chile was evaluated in the presence of COVID-19 and mobility restrictions. The fire period from 2015-2016 to 2020-2021 was considered and statistics on mobility restrictions were granted by the Government of Chile. The analysis was developed at different scales of geographic perception. At the national and regional levels, the global behavior of the occurrence was determined, and later at the communal level, the political territorial unit, to determine internal variations attributable to the mobility dynamics in the quarantine period. In the process, the meteorological background of the fire activity was also considered. The results indicate that it is possible to rule out a meteorological effect, based on the variation of the moisture content of fine fuel. There was also no statistical association between the humidity of the fuel and the variation in the occurrence of fires. It is concluded that the communes that presented the greatest mobility of people before the pandemic were those that obtained the greatest reduction in fires. The variation in mobility, the product of restriction measures, is a statistical predictor of the increase or decrease in fires.

Although forest fires are indispensable for some ecosystems, they can have profound economic, environmental, and social implications, especially when they reach high intensities. There are two crucial factors in fighting forest fires: the availability of water resources and the service network. The objective of this study was to propose an alternative methodology for allocating water reservoirs to fight forest fires. The research was divided into three stages: zoning of fire risk, delimitation of viable areas for the implementation of water reservoirs, and determining strategic locations for reservoir allocation. The variables analyzed were land use and occupation, provision of watercourses, relief orientation, slope, proximity to roads, temperature, and precipitation. Fuzzy logic, Euclidean distance, and network analysis were used as the modeling techniques. Scenarios with all risk classes and only the high- and very high-risk classes were analyzed. A total of 66% of the area was represented by the low- and moderate-risk fire classes and 53.16% had a low potential for reservoir allocation, influenced by the low availability of water resources in the area. The proposed model efficiently allocated the water collection points in the different scenarios, and allowed the determination of the areas most susceptible to the occurrence of forest fires and the optimal locations for the installation of reservoirs, with the allocation of 21 water reservoirs to attend the areas of high- and very high-risk of occurrence of fires at a safe speed (40 km h-1) and 47 reservoirs to meet all risk classes at the same speed. The proposed methodology is feasible, applicable, and adjustable and can be implemented in other conservation units and areas of economic interest.

Water supply impairment from increased contaminant mobilization and transport after wildfire is a major concern for communities that rely on surface water from fire-prone watersheds. In this article we present a Monte Carlo simulation method to quantify the likelihood of wildfire impairing water supplies by combining stochastic representations of annual wildfire and rainfall activity. Water quality impairment was evaluated in terms of turbidity limits for treatment by modeling wildfire burn severity, postfire erosion, sediment transport, and suspended sediment dilution in receiving waterbodies. Water supply disruption was analyzed at the system level based on the impairment status of water supply components and their contributions to system performance. We used this approach to assess wildfire-water supply impairment and disruption risks for a system of water supply reservoirs and diversions in the Front Range Mountains of Colorado, USA. Our results indicate that wildfire may impair water quality in a concerning 15.7-19.4% of years for diversions from large watersheds. Reservoir impairment should be rare for off-network reservoirs-ranging from at most 0.01% of years for large reservoirs to nearly 2% of years for small reservoirs. System redundancy meaningfully reduced disruption risk for alternative conveyance routes (4.3-25.0% reduction) and almost eliminated disruption risk for a pair of substitutable terminal sources (99.9% reduction). In contrast, dependency among reservoirs on a conveyance route nearly doubled risk of disruption. Our results highlight the importance of considering water system characteristics when evaluating wildfire-water supply risks.

A number of watershed partnerships have emerged in the western US to address the impacts of wildfire through investing in wildfire mitigation activities. To motivate collective action and design effective risk mitigation programs, these stakeholders draw on evidence linking wildfire mitigation to outcomes of interest. To advance knowledge in this area, we 1) assessed the strength of existing scientific evidence linking wildfire mitigation treatments with societal outcomes and 2) measured the importance of this evidence to watershed partnerships in the western US. To address objective one, we created a systematic evidence map to identify the most common wildfire mitigation treatment and societal outcome relationships reported. From the more than 100 studies examined, we found that the most commonly studied linkages were related to the impacts of thinning on infrastructure and timber. To answer objective two, we surveyed 38 professionals affiliated with organizations involved in eight watershed partnerships in the western US. We asked about the relative importance and strength of evidence linking wildfire treatments to societal outcomes for their watershed partnership, and used this information to create an importance-strength analysis and gap analysis. We found that most linkages were considered important to these organizations, and that the biggest gap identified was for evidence linking mulching to water quality or quantity outcomes. Forest and wildfire specialists perceived a larger need for additional evidence generation than other professional groups. Jointly, the results from this study point to areas of evidence generation important for watershed partnerships and other organizations involved in wildfire mitigation, and suggest a need to more thoroughly disseminate information about existing evidence to this new group of stakeholders investing in wildfire risk mitigation.

Wildfires are common in wildland-urban interfaces (WUIs), where they represent a severe threat to inhabited urban settlements endangering both infrastructure and human life. Given these hazards, it is critical that forest management tools be designed to reduce the risk of wildfire at the WUI. In this regard, a management tool that is increasingly being adopted is that of prescribed fires; however, a complete understanding of their impact has yet to be gained. The aim of this study, therefore, is to analyze long-term soil properties after a prescribed fire and observed if the prescribed fire avoids vegetal fuel continuity. Our study area occupies a Mediterranean forest in the urban settlement of Picarany in the municipality of Almoster (Tarragona, Spain). The vegetation is composed primarily of Pinus halepensis Miller. and Quercus ilex L. and the soil type is classified as Xerorthents. Soil sampling was carried out in four campaigns: just before the prescribed fire (BPF), just after (APF), one year after (1YAPF) and 13 years after the prescribed fire (13YAPF). In each sampling period, 30 samples were taken (0-2.5 cm) from a 72-m2 experimental plot (4 × 18 m). The soil properties analyzed were total nitrogen (TN), soil organic matter (SOM), pH, electrical conductivity (EC) and extractable calcium (Ca), magnesium (Mg), potassium (K) and available phosphorus (P) concentrations. The carbon/nitrogen ratio was also calculated. A comparison of pre-fire values (2004) with long-term results (2017) shows increases of EC, Ca and Mg and decreases of TN and SOM. Despite these changes, the prescribed fire was found to be a good tool for managing forest areas. Indeed, the changes in soil properties did not represent a severely degradation of the soil and after 13 years there was no horizontal or vertical fuel continuity in the wildland-urban interface.