Search Results (1,138)

Understanding the potential effects of climate change on forest fire behavior and the resulting release of combustion products is critical for effective mitigation strategies in Greece. This study utilizes data from the MAGICC 2.4 (Model for the Assessment of Greenhouse Gas-Induced Climate Change) climate model and the SCENGEN 2.4 (SCENarioGENerator) database to assess these impacts. By manipulating various model parameters such as climate sensitivity, scenario, time period, and global climate models (GCMs) within the SCENGEN 2.4 database, we analyzed climatic trends affecting forest fire generation and evolution. The results reveal complex and nuanced findings, indicating a need for further investigation. Case studies are conducted using the FARSITE 4 (Fire Area Simulator) model, incorporating meteorological changes derived from climate trends. Simulations of two fires in East Attica, accounting for different fuel and meteorological conditions, demonstrate an increase in the rate of combustion product release. This underscores the influence of changing meteorological parameters on forest fire dynamics and highlights the importance of proactive measures to mitigate future risks. Our findings emphasize the urgency of addressing climate change impacts on wildfire behavior to safeguard environmental and public health in Greece. Full article

This review paper investigates the landscape of wildfire-related studies with a focus on infrastructure and evacuations across Canadian provinces, revealing a predominant focus on Alberta, particularly after the 2016 Fort McMurray wildfire. The aftermath of this event has heightened attention to the unique challenges faced during evacuations, emphasizing the urgent need for heightened awareness and preparedness, especially in the vulnerable northern communities of Alberta. Studies beyond Alberta contribute to understanding Canadian wildfire dynamics. However, a noticeable research gap in British Columbia raises concerns about research prioritization and resource allocation despite heightened wildfire activity. The fact that some provinces are contributing less than 4.2%, such as Quebec, Saskatchewan, Ontario, Northwest Territories, Yukon, and the Prairies, might be attributed to regional variations influenced by historical wildfire frequency and population density. Thematic analysis categorizing studies into “community support/resilience”, “evacuation efficiency”, and “infrastructure protection/raising awareness” provides nuanced insights. The dominance of the “community support/resilience” category, comprising over 40% of studies, signifies a societal shift towards proactive community engagement. Balanced representation in the “evacuation efficiency” and “infrastructure protection/raising awareness” categories, each contributing over 29%, reflects a collective effort to glean lessons from past evacuations and enhance community preparedness. Temporal trends and thematic analyses spotlight a commitment to continuous improvement, adaptability to emerging challenges, and a growing recognition of the multifaceted aspects of wildfire management. The evolving emphasis on community involvement, responsiveness to changing evacuation dynamics, and heightened awareness of infrastructure protection underscores the proactive stance of the research community, providing insights for shaping future research priorities, policy frameworks, and community resilience strategies in the face of evolving wildfire threats in Canada. Full article

Parts of the Cantabrian Mountains (N Spain) have been colonized by woody species in the past six or seven decades as a result of a decline in livestock activity and changes in the fire regime. Various management strategies have been used to prevent the expansion of shrubs and recover grassland ecosystems for grazing activities. However, it is not clear how different vegetation treatments affect soils, which are crucial in supporting life and providing nutrients in these ecosystems. The aim of the present study was to compare the dynamics of the physicochemical and biological soil properties after two vegetation treatments: prescribed burning and shredding. Samples were obtained from plots representing alkaline and acidic soils dominated by gorse shrub (Genista hispanica subsp. occidentalis) and heath (Calluna vulgaris) plant communities, respectively. The soil samples were collected immediately before and after the treatments and one and two years later. The level of available P varied depending on the soil pH, and it only increased after the treatments in the acidic soils in the heathland community. The total N and available P concentrations were higher after the prescribed burning, and the enzymatic activity tended to be higher after the shredding treatment. Despite the significant effects on some soil variables, prescribed burning and shredding did not have important short- and medium-term effects on the chemical and soil enzymatic properties. These treatments can therefore be considered sustainable vegetation management tools, at least in the medium term. Full article

The erosion of igneous rocks affects the structural and spontaneous combustion characteristics of coal. A series of tests were conducted, including programmed heating, thermogravimetric analysis, FT-IR spectroscopy, low-temperature nitrogen adsorption, and pressed mercury experiments on samples from primary coal and coal eroded by igneous rocks from the Tashan Mine and Xiaonan Mine within the same coal seam. Based on these experiments, we analyzed various properties of coal, such as the oxidation characteristics, spontaneous combustion limit, active functional group content, chemical structure, and pore structure, from both macroscopic and microscopic perspectives. The results indicated significant trends after the erosion of igneous rocks: (1) there were increases in the oxygen consumption rate, as well as the CO and CO₂ release rates; (2) the upper limit of air leakage intensity increased, the minimum thickness of floating coal decreased, and the lower limit of oxygen volume fraction decreased; (3) there was a decrease in the activation energy required for coal ignition; (4) there was a decrease in the active functional group content while improving the structural stability; and (5) there were the alterations in the pore structure of coal. These promoted the oxidation reactions between oxygen and the active groups within the coal matrix, increasing the propensity for spontaneous combustion, particularly in the igneous rocks with low oxidation activity. Full article

In this research, the influence of confined space size on the temperature distribution characteristics of internal window plumes from well-ventilated compartment fires was studied. Theoretical analysis was firstly used to establish a mathematical model for the smoke after ejecting from the window in the space. The study considered fire heat release rate and vertical height as dependent variables. Numerical simulations and experimental methods were carried out to study the temperature variations. A critical distance L₂ was obtained. Results show that when the space D between the vertical retaining wall and the building façade is greater than L₂, the variation of D has little influence on radial temperature. Once D is less than L₂, the radial temperature distribution inside the confined space will tend to be consistent, and the temperature in the confined space sharply increases as D decreases. In addition, a dimensionless model was derived to quantify the relationship between temperature rise and vertical height. The experimental and numerical simulation results were processed, which are in good agreement with the model. The study can provide a framework for managing building safety. Full article

Wildland fire dispatchers play a key role in wildland fire management and response organization; however, to date, wildland fire studies have largely focused on the physical hazards and, to a lesser extent, mental health hazards of wildland firefighting operational personnel, and dispatcher studies have primarily focused on 911 and police dispatchers. Studies of other dispatchers have provided some limited insight into potential strains impacting this workforce, including work-related fatigue, burnout, and traumatic exposure. However, the specific job hazards that are faced by wildland fire dispatchers are poorly understood. In 2023, we conducted a cross-sectional survey of 510 wildland fire dispatchers with questions about their occupational health, general health, and well-being. We used validated screening instruments to measure the rates of anxiety, depression, PTSD, and suicidal thoughts and ideation. Here, we also present the results of mental health and trauma exposure questions that were asked as part of a larger survey. We found that demographic factors were significant indicators of anxiety, depression, and binge/restrictive eating. Our data indicate that rates of anxiety, depression, PTSD, and suicidal thoughts and ideation are significantly higher for both the wildland fire dispatching workforce and other emergency responder populations than those of the general United States population. Full article

The firefighting protective suits (FPSs) of firefighters at fire scenes affect their health and safety. However, the association between firefighters’ health awareness of occupational exposure risks and the FPS use, washing and management remains unclear. Therefore, this study aimed to evaluate the association between firefighters’ health awareness of occupational exposure risks and their recognition, behaviors regarding the use, washing and management of FPSs. This study design is a cross-sectional study and used a web-based survey of the Seoul Metropolitan Government’s electronic survey system. The survey was conducted on metropolitan firefighters performing shift work in charge of fire and rescue work for 21 days from 1 to 22 April 2019, with 1097 (40.3%) respondents. Characteristics of FPS use, washing and management and the association between thoughts and behaviors thereof and health awareness of occupational exposure risks were evaluated. Data of 1097 firefighters were analyzed using the SAS 9.4 statistical package, chi-square test and logistic regression analysis. Firefighters’ fire scene awareness rate of possible carcinogens was 94.4%. There was an association between public health thinking of occupational exposure risks and the correct use of an FPS for one’s own safety (AOR 1.97. 95% CI 1.02–3.80). However, no association was shown between correct FPS use (AOR 1.49, 95% CI 0.48–4.59), washing (AOR 2.50, 95% CI 0.93–6.68) and management (AOR 1.38, 95% CI 0.75–2.50) behaviors. This study analyzed the relationship between the use, washing and management of personal protective equipment called firefighting clothing and firefighters perceived occupational exposure risks. This study found an association between the health awareness of occupational exposure risks and recognition of the correct use of FPSs at fire scenes but not between using, washing and managing behaviors of FPSs. This study is the first to analyze the relationship between firefighting clothing and occupational health awareness level. The results confirm that future interventions are required to help firefighters practice desirable behaviors toward FPSs and provided evidenced data for preventing occupational diseases among firefighters. Therefore, this study can be used to develop a firefighter occupational health curriculum and establish health and safety plans from mid- to long-term perspectives for firefighters’ safety against occupational exposure risks. Full article

This study offers a comprehensive examination, both theoretically and experimentally, of the potential of methanol (M) as a sustainable aviation fuel (SAF) assessed in combination with kerosene (Ke—Jet-A aviation fuel + 5% Aeroshell oil). Different blends of methanol and kerosene (10%, 20%, and 30% vol. of (M) was added to Ke) were tested in an aviation micro turbo-engine under various operating regimes, such as idle, cruise, and maximum. Key engine parameters, including combustion temperature, fuel consumption, and thrust, were closely monitored during these trials. Essential performance indicators such as combustion efficiency, thermal efficiency, and specific consumption for all fuel blends under maximum operating conditions are also presented. Physical and chemical characteristics, such as viscosity, density, calorific value and flash point, were determined for each blend. Moreover, elemental analysis and FTIR spectroscopy were utilized to evaluate the chemical composition of the fuels. This study further investigated the air requirements for stoichiometric combustion and computed the resulting CO₂ and H₂O emissions. Experimental tests were conducted on the Jet Cat P80^® micro turbo-engine, covering assessments of starting procedures, acceleration, deceleration, and pollutant emissions (CO and SO₂) during various engine operating conditions. The results suggest that the examined fuel blends demonstrate stable engine performance at concentrations of 10% and 20% methanol. However, observations indicate that with an increase in methanol concentration, particularly at 30%, the stability of the engine at idle and, notably, at maximum speed decreases significantly. Specifically, at a 30% methanol concentration, the engine no longer operates stably, exhibiting significant rpm fluctuations, leading to the decision not to explore higher concentrations. Full article

Accurate comprehension of grassland fires is imperative for maintaining ecological stability. In this study, we propose a novel fire model that incorporates real-time meteorological conditions. Our methodology integrates key meteorological factors including relative humidity, temperature, degree of solidification of combustible materials, and wind speed. These factors are embedded into a comprehensive function that determines both the downwind and upwind spreading speeds of the fire. Additionally, the model accommodates fire spread in the absence of wind by incorporating the direction perpendicular to the wind, with wind speed set to zero. By precisely determining wind speed, the model enables real-time calculation of fire spread speeds in all directions. Under stable wind conditions, the fire spread area typically adopts an elliptical shape. Leveraging ellipse properties, we define the aspect ratio as a function related to wind speed. Consequently, with knowledge of the fire duration, the model accurately estimates the area of fire spread. Our findings demonstrate the effectiveness of this model in predicting and evaluating fires in the Hulunbuir Grassland. The model offers an innovative method for quantifying grassland fires, contributing significantly to the understanding and management of grassland ecosystems. Full article

Ember accumulation on and around homes can lead to spot fires and home ignition. Post wildland fire assessments suggest that this mechanism is one of the leading causes of home destruction in wildland urban interface (WUI) fires. However, the process of ember deposition and accumulation on and around houses remains poorly understood. Herein, we develop a deep learning (DL) model to analyze data from a series of ember-related wind tunnel experiments for a range of wind conditions and roof slopes. The developed model is designed to identify building roof regions where embers will remain in contact with the rooftop. Our results show that the DL model is capable of accurately predicting the position and fraction of the roof on which embers remain in place as a function of the wind speed, wind direction, roof slope, and location on the windward and leeward faces of the rooftop. The DL model was augmented with explainable AI (XAI) measures to examine the extent of the influence of these parameters on the rooftop ember coverage and potential ignition. Full article

The effect of the mainline slope on the ceiling temperature profile in a branched tunnel has not been clarified nor included in existing models. Thus, in this paper, the numerical code was employed to investigate the induced airflow velocity and gas temperature beneath the ceiling in a branch tunnel with a sloped upstream mainline. The mainline slope varied from 1% to 7%, with an interval of 1%. Five fire power of 3 MW, 5 MW, 10 MW, 15 MW, and 20 MW are employed on each slope. The airflow velocity and the longitudinal temperature in the mainline tunnel are measured and analyzed. Results show that the stack effect obviously occurred, which caused longitudinal velocity to prevent the smoke reverse flow in the mainline. The induced airflow velocity in the upstream inclined mainline is higher with increasing slope, and the dimensionless velocity is normalized well by the proposed expression. The maximum ceiling temperature is independent of the mainline slope and correlated well by Q^*2/3, but the effect of the mainline slope on temperature longitudinal decay is worth considering. Finally, a normalized expression for longitudinal temperature decay in an inclined mainline is proposed by taking the fire power and mainline slope into account. Full article

With the development of image processing technology and video analysis technology, forest fire monitoring technology based on video recognition is more and more important in the field of forest fire prevention and control. The objects currently applied to forest fire video image monitoring system monitoring are mainly flames and smoke. This paper proposes a forest fire risk monitoring and early warning algorithm, which integrates a deep learning model, infrared monitoring and early warning, and forest fire weather index. The algorithm first obtains the current visible image and infrared image of the same forest area, utilizing a smoke detection model based on deep learning to detect smoke in the visible image, and obtains the confidence level of the occurrence of fire in said visible image. Then, it determines whether the local temperature value of said infrared image exceeds a preset warning value, and obtains a judgment result based on the infrared image. It calculates again a current FWI based on environmental data, and determines a current fire danger level based on the current FWI. Finally, it determines whether or not to carry out a fire warning based on said fire danger level, said confidence level of the occurrence of fire in said visible image, and said judgment result based on the infrared image. The experimental results show that the accuracy of the algorithm in this paper reaches 94.12%, precision is 96.1%, recall is 93.67, and F1-score is 94.87. The algorithm in this paper can improve the accuracy of smoke identification at the early stage of forest fire danger occurrence, especially by excluding the interference caused by clouds, fog, dust, and so on, thus improving the fire danger warning accuracy. Full article

Complying with strict PM₁₀ and PM_2.5 limit values poses challenges in many European regions, influenced by diverse factors such as natural, regional, and local anthropogenic sources. Urban air pollution, exacerbated by road transport, local industry, and dust resuspension, contrasts with rural areas affected by solid fuel-based local heating and increasing wood burning. This study focuses on village of Sučany, located in Slovakia, analysing PM concentrations during non-heating and heating seasons. The method of analysis relies on the use of the MP101M air quality analyser that utilises beta radiation absorption method. One set of measurements was conducted at five distinct locations during the heating season (18/01/2019 to 28/02/2019) and non-heating season (14/08/2018 to 1/10/2018). Significant differences emerged during the non-heating season with corresponding PM₁₀ averages of 23.0 µg/m³ and PM_2.5 at 19.3 µg/m³. In contrast, the PM₁₀ averaged 53.9 µg/m³ and 52.8 µg/m³ during the heating season. The heating season shows PM_2.5 contributing up to 98% of total PM₁₀. The distribution of PM₁₀ and PM_2.5 pollution and the location of the potential source obtained using polar plots differed during the heating and non-heating seasons. This research underscores the impact of local heating on air quality in a typical Slovak village. The key recommendation for targeted interventions is supporting up-to-date air quality data, education, and financial incentives for citizens in order to implement cleaner and modern heating solutions. Full article

Considering that the determination of fire hazard zones in warehouses is not sufficiently researched and studied, this paper aims to present a new methodological approach concerning the mentioned issue. Based on the COPRAS multi-criteria decision-making method, a new method was developed for the precise determination of potential zones where there is a risk of fire. The advantage of the described method is that it allows the quick and easy determination of all-orientation fire risk zones. The method requires fewer hardware resources compared to the existing ones and enables the display of the warehouse space in the form of a 3D model with calculated fire hazard zones. The mentioned procedure represents the first step when planning the layout and arrangement in the warehouse itself. The effectiveness of the proposed method was confirmed through a suitable numerical example. Full article

Many plant species are well-adapted to historical fire regimes. An increase in the severity, frequency, and extent of wildfires could compromise the regenerative capacity of species, resulting in permanent shifts in plant diversity. We surveyed extant vegetation and soil seed banks across two forest types with contrasting historical fire regimes—Shrubby Dry Forest (fire return interval: 10–20 years) and Sub-Alpine Woodland (50–100 years). Over the past 20 years, both forests have been subject to repeated, high-severity wildfires at intervals significantly shorter than their historical return intervals. We examined the soil seed bank response to fire-cued germination, and whether the plant diversity in soil seed banks and extant vegetation demonstrated similar responses to short-interval, high-severity wildfires. The soil seed bank demonstrated a positive response to heat in combination with smoke, and for the Sub-Alpine Woodland, this was limited to sites more frequently burnt by fire. With an increase in fire frequency, there was a decline in species richness and Shannon’s Diversity and a shift in species composition in both extant vegetation and the soil seed bank. The fire frequency effects on the relative richness of trait associations were restricted to the Shrubby Dry Forest, and included an increase in short-lived obligate seeders, wind-dispersed species, and ant-dispersed shrubs in burnt relative to long unburnt sites in both extant vegetation and the soil seed bank. Graminoids were the most abundant component of the soil seed banks of Sub-Alpine Woodlands, and this increased with more frequent fire, with a similar trend (p = 0.06) in extant vegetation. Clear shifts in plant diversity in both soil seed banks and extant vegetation in forest types with contrasting historical fire regimes suggest that emerging fire regimes are pushing ecosystems beyond their historical range of variability, including potentially more flammable states and a decline in the buffering capacity of soil seed banks. Full article