Search Results (807)

Targeting the challenges in the risk analysis of laboratory fire accidents, particularly considering fire accidents in Chinese universities, an integrated approach is proposed with the combination of association rule learning, a Bayesian network (BN), and fuzzy set theory in this study. The proposed approach has the main advantages of deriving conditional probabilities of BN nodes based on historical accident data and association rules (ARs) and making good use of expert elicitation by using an augmented fuzzy set method. In the proposed approach, prior probabilities of the cause nodes are determined based on expert elicitation with the help of an augmented fuzzy set method. The augmented fuzzy set method enables the effective aggregation of expert opinions and helps to reduce subjective bias in expert elicitations. Additionally, an AR algorithm is applied to determine the probabilistic dependency between the BN nodes based on the historical accident data of Chinese universities and further derive conditional probability tables. Finally, the developed fuzzy Bayesian network (FBN) model was employed to identify critical causal factors with respect to laboratory fire accidents in Chinese universities. The obtained results show that H4 (bad safety awareness), O1 (improper storage of hazardous chemicals), E1 (environment with hazardous materials), and M4 (inadequate safety checks) are the four most critical factors inducing laboratory fire accidents. Full article

The effectiveness of fire towers in combating forest fires relies on their appropriate observation angles, enabling a swift and efficient response to fire incidents. The purpose of this study is to examine the effectiveness of 49 fire towers located within the Antalya Forestry Regional Directorate, situated in the Mediterranean basin—a region prone to frequent forest fires. The assessment encompasses the visibility of the entire study area, including forested regions, as well as the visibility of 2504 forest fires recorded by the towers between 2008 and 2021. Furthermore, the evaluation considers the objectives based on Forest Management Directorates and conducts a location suitability analysis for the six towers with the lowest visibility. We utilized the Viewshed Tool in the ArcGIS application and employed the Best–Worst approach. Two scenarios were devised, considering smoke height at 0 m or 100 m, to determine the visibility of fire lookout towers. In Scenario I, assuming a smoke height of 100 m, only three towers exhibited visibility above 70%. However, in Scenario II, assuming a smoke height of 0 m, no towers achieved visibility above 70%. Scenario I indicated that only two towers possessed a view of more than 70% of the forested region, while Scenario II suggested that no towers met this criterion. For the visibility of forest fires, Scenario I identified seven towers capable of observing more than 70%, whereas Scenario II indicated that no towers possessed such capability. In the tower suitability analysis, the visibility rates varied from 41.18% to 1016.67%. Based on the evaluation results, the current visibility capacities of the 49 fire towers proved insufficient for effective preventive measures. Full article

Large areas of forests burn annually in Siberia. Pyrogenic organic matter (PyOM) generated by wildfires acts as a stable carbon deposit and plays an important role in the global carbon cycle. Little is known about the properties of PyOM formed during fires in Siberian forests. In this work, we report the results of thermogravimetry (TG), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy applied to the study of the chemical composition, structure, and thermal stability of PyOM formed during surface and crown fires of moderate to high severity in southern Siberia. We studied the PyOM produced from the forest floor, down wood, cones, and outer bark of tree stems in Scots pine, larch, spruce, and birch forests. We calculated the thermal recalcitrance indexes (R₅₀, Q₃) based on TG/DSC data. We found that wildfires resulted in a strong decrease in thermolabile components in burned fuels, enrichment by aromatic structures, and a significant increase in thermal stability (T₅₀) compared to unburned samples. In all the studied forests, bark PyOM revealed the highest value of T₅₀ while forest floor PyOM had the lowest one. At the same time, our results indicated that the properties of PyOM were more strongly driven by wildfire severity than by fuel type. Overall, the thermal recalcitrance R₅₀ index for PyOM samples increased by 9–29% compared to unburned plant residues, indicating a shift from low to intermediate carbon sequestration potential class in the majority of cases and hence less susceptibility of PyOM to biodegradation. Full article

This study developed an objective approach for determining fire source location based on an artificial neural network (ANN) model. The samples for the ANN model were obtained from computational fluid dynamics simulations. A data preprocessor was devised to transform numerical simulation results into a format that could be used by the ANN model prior to network training, and bootstrap aggregation was used to improve the model’s predictive performance, which was evaluated by the leave-one-out approach. The results show that the 95% left-tailed confidence limit was 0.7921 m for planar dimensions of 5 m × 5 m, which is sufficiently accurate for practical application. Additionally, comprehensive experiments were conducted in the confined space of a fire compartment that was geometrically similar to various fire source locations to explore soot patterns and verify the ANN model. The experimental results reveal that the differences between the locations determined in scaling experiments and the locations predicted by the ANN were invariably less than 1 m. In particular, the difference was only 0.17 m when the fire source was located in the centre of the fire compartment. These results demonstrate the feasibility of the devised ANN model for reconstructing fire source location in engineering applications. Full article

Efforts to delineate the influence of atmospheric variability on regional wildfire activity have previously been complicated by the stochastic occurrence of ignition and large fire events, particularly for Southern California, where anthropogenic modulation of the fire regime is extensive. Traditional metrics of wildfire activity inherently contain this stochasticity, likely weakening regional fire–climate relationships. To resolve this complication, we first develop a new method of quantifying regional wildfire activity that aims to more clearly capture the atmospheric fire regime component by aggregating four metrics of fire activity into an annual index value, the Annual Fire Severity Index (AFSI), for the 27-year period of 1992–2018. We then decompose the AFSI into trend and oscillatory components using singular spectrum analysis (SSA) and relate each component to a set of five climate predictors known to modulate macroscale fire activity in Southern California. These include the Atlantic Multidecadal Oscillation (AMO), Pacific Decadal Oscillation (PDO), El Niño–Southern Oscillation (ENSO), and Santa Ana wind (SAW) events, and marine layer frequency. The results indicate that SSA effectively isolates the individual influence of each predictor on AFSI quantified by generally moderate fire–climate correlations, $\left|r\right|>0.4$, over the full study period, and $\left|r\right|>0.5$ over select 13–15-year periods. A transition between weaker and stronger fire–climate relationships for each of the oscillatory PC–predictor pairs is centered around the mid-2000s, suggesting a significant shift in fire–climate variability at this time. Our approach of aggregating and decomposing a fire activity index yields a straightforward methodology to identify the individual influence of climatic predictors on macroscale fire activity even in fire regimes heavily modified by anthropogenic influence. Full article

Throughout the larch range, warming leads to frequent fires and an increase in burned areas. We test the hypothesis that fires are an essential natural factor that reset larch regeneration and support the existence of larch forests. The study area included Larix sibirica and L. gmelinii ranges within the permafrost zone. We used satellite-derived and field data, dendrochronology, and climate variables analysis. We found that warming led to an increase in fire frequency and intensity, mean, and extreme (>10,000 ha) burned areas. The burned area is increasing in the northward direction, while fire frequency is decreasing. The fire rate exponentially increases with decreasing soil moisture and increasing air temperature and air drought. We found a contrasting effect of wildfire on regeneration within continuous permafrost and within the southern lowland boundary of the larch range. In the first case, burnt areas regenerated via abounded larch seedlings (up to 500,000+ per ha), whereas the south burns regenerated mostly via broadleaf species or turned into grass communities. After the fire, vegetation GPP was restored to pre-fire levels within 3–15 years, which may indicate that larch forests continue to serve as carbon stock. At the southern edge of the larch range, an amplified fire rate led to the transformation of larch forests into grass and shrub communities. We suggested that the thawing of continuous permafrost would lead to shrinking larch-dominance in the south. Data obtained indicated that recurrent fires are a prerequisite for larch forests’ successful regeneration and resilience within continuous permafrost. It is therefore not necessary to suppress all fires within the zone of larch dominance. Instead, we must focus fire suppression on areas of high natural, social, and economic importance, permitting fires to burn in vast, larch-dominant permafrost landscapes. Full article

Historical land and fire management practices coupled with climate change and modern human development pressures are contributing to larger, more frequent, and more severe wildfires across Western U.S. forests. Human ignitions are the predominant cause of wildfire throughout the United States, necessitating wildfire management strategies that consider both the causes of human ignitions and the factors that influence them. Using a dataset of over 104,000 ignitions from 1992 to 2018 for Oregon and Washington (U.S), we examine the major causes of wildfire ignitions and build regression models to evaluate the potential influence of both biophysical and socioeconomic factors on human and natural ignitions across distinct fire regimes west and east of the Cascade Range. Our results corroborate prior findings that socioeconomic factors such as income, employment, population density, and age demographics are significantly correlated with human ignitions. In the Pacific Northwest, we found that the importance of socioeconomic factors on human ignitions differs significantly between the west and east sides of the Cascade Range. We also found that most human ignitions are linked to escaped fires from recreation or debris and open burning activities, highlighting opportunities to tailor wildfire prevention efforts to better control higher risk activities and reduce accidental ignitions. Full article

As a way to accommodate the rising demand for “green” wood-based products, agricultural waste from Areca (Areca catechu) nut farms, which is generally burned on-site, can be used to raise the value of alternative lignocellulosic raw materials. This research aimed to investigate and evaluate the effect of technical lignin (kraft lignin or lignosulfonate) addition on particleboard properties from areca bonded with ultra-low-emitting urea formaldehyde (UF) resin. The physical properties, mechanical properties, and fire resistance of the laboratory-made particleboards were tested and evaluated in accordance with the applicable Japanese industrial standards (JIS). The highest density of 0.84 g/cm³ was determined for the laboratory boards, bonded with an adhesive mixture of UF resin and kraft lignin with three washing treatments. The lowest moisture content of 9.06%, thickness swelling of 71.16%, and water absorption of 129.17% were determined for the boards bonded with lignosulfonate with three washing treatments, with commercial lignin, and with lignosulfonate with five washing treatments, respectively. The highest MOR and MOE values, i.e., 113.49 kg/cm² and 10,663 kg/cm², respectively, were obtained for the particleboards bonded with lignosulfonate with five washing treatments. Interestingly, all laboratory boards exhibited good fire resistance following the UL-94 standard. Based on the gas torch test, the lowest weight loss of 16.7% was determined in the boards fabricated with lignosulfonate with five washing treatments. This study demonstrated that adding lignin-based fire retardants represents a viable approach to producing lignocellulosic composites with enhanced fire resistance and a lower carbon footprint. Full article

The Victorian Government Inquiry into wildfires that killed 173 people in 2009 has driven an Australian policy shift from self-evacuation or staying and defending a well-prepared property (‘go or stay’) to self-evacuation under catastrophic fire weather (‘leave early’). The Inquiry also led to the establishment of national ‘performance standards’ for Private Fire Shelters (PFSs, that are also known as bunkers). Nonetheless, the incorporation of PFSs into national bushfire policy remains embryonic, with only Victoria having streamlined accreditation and planning approval processes. Arguments against PFSs include potentially engendering complacency about preparing dwellings to survive fire and encouraging risky behaviour in response to a fire threat. Counteracting these arguments is research that shows that residents without PFSs have low engagement with bushfire preparation and typically delay evacuation. In any case, because wildfire is unpredictable, it is accepted that self-evacuation plans must have fallback positions that include sheltering ‘in place’ from the bushfire, making properly used and well-maintained PFSs an important element of bushfire safety. A less discussed barrier to PFS uptake outside Victoria appears to hinge on a lack of clarity about obligations for their design, certification, and consistency with planning approvals. The escalating Australian fire crisis demands much greater research and development in legal frameworks, policy and planning processes for PFSs, as well as design and construction standards. Progress in enhancing Australian laws and policies on this issue may offer important opportunities for other jurisdictions that will experience similar challenges as climate change intensifies fire regimes around the world. Full article

The layout of a city is complex, and indoor spaces have thousands of aspects that make them susceptible to fire. If a fire breaks out, it is difficult to quell, so a fire in the city will cause great harm. However, the traditional fire detection algorithm has a low detection efficiency and high detection rate of small targets, and disasters have occurred during detection. Therefore, this paper proposes a fire safety detection algorithm based on CAGSA-YOLO and constructs a fire safety dataset to integrate common fire safety tools into fire detection, which has a preventive detection effect before a fire occurs. In the improved algorithm, the upsampling in the original YOLOv5 is replaced with the CARAFE module. By adjusting its internal Parameter contrast, the algorithm pays more attention to local regional information and obtains stronger feature maps. Secondly, a new scale detection layer is added to detect objects larger than 4 × 4. Furthermore, the sampling Ghost lightweight design replaces C3 with the C3Ghost module without reducing the mAP. Finally, a lighter SA mechanism is introduced to optimize visual information processing resources. Using the fire safety dataset, the precision, recall, and mAP of the improved model increase to 89.7%, 80.1%, and 85.1%, respectively. At the same time, the size of the improved model is reduced by 0.6 M to 13.8 M, and the Param is reduced from 7.1 M to 6.6 M. Full article

This paper aims to provide a better understanding of the transition towards a new paradigm of wildfire risk management in Victoria that incorporates Aboriginal fire knowledge. We show the suitability of cultural burning in the transformed landscapes, and the challenges associated with its reintroduction for land management and bushfire risk reduction after the traumatic disruption of invasion and colonization. Methods of Environmental History and Regional Geography were combined with Traditional Ecological Knowledge to unravel the connections between past, present and future fire and land management practices. Our study area consists of Dja Dja Wurrung and Bangarang/Yorta Yorta Country in north-central Victoria. The results show (i) the ongoing socio-political process for building a renewed integrated fire and land management approach including cultural burning, and (ii) the opportunities of Aboriginal fire culture for restoring landscape resilience to wildfires. We conclude that both wildfire risk management and cultural burning need to change together to adapt to the new environmental context and collaborate for mutual and common benefit. Full article

One of the most effective methods of preventing large-scale wildfires is creating fuelbreaks, buffer zones whose purpose is to stop or delay the spread of the fire, providing firefighters an opportunity to control the fire. Fuelbreaks are already applied in several countries and have proven their effectiveness. However, creating fuelbreaks involves deforestation, so the length of the fuelbreaks should be minimized as much as possible. In this paper, we propose the implementation of a greedy Dijkstra-based fuelbreak planning algorithm which identifies locations in which fuelbreaks could significantly reduce the risk of large wildfires, at a relatively low deforestation cost. We demonstrate the stages and output of the algorithm both on artificial forests and on actual forests in Israel. We discuss the factors which determine the cost effectiveness of fuelbreaks from a tree-economy perspective and demonstrate how fuelbreaks’ effectiveness increases as large wildfires become more frequent. Full article

The paper presents the results of the development of a multi-layer protective product, which is a transformable fire barrier, installed in buildings and structures to limit the spread of flame, heat flow and smoke. Based on the results of the simulation of eight samples of fire curtains, three promising samples of different compositions were selected, demonstrating a fire resistance limit on the loss of thermal insulating capacity (I) of 30 min. During the small-scale tests, it was found that the multilayer fabric of the following composition was promising: heat-treated silica fabric, aluminum foil, mineral fiber heat insulation material, stitched by needle-punching with silica thread, fabric reinforced with fiberglass mesh and stitched through with basalt thread, with seams treated with a fire-resistant elastic sealant. According to the results of a standard large-scale experimental study, a fire curtain with a loss of integrity not less than 60 min, and a loss of thermal insulating ability not less than 15 min were obtained. The results of the study assess the impact of the scale factor on the fire resistance limit of fire curtains in a fire. Full article

The recent expansion of logistics capacities entails the installation of chemical warehouses, which operations increase the occurrence of compartment fires involving flammable dangerous substances. The aim of this research was to compare and analyze the fire behavior of beams made of different structural materials but with the same load capacity. It is assumed that wooden beams, which are less commonly used in industrial facilities, may have a similar or even better load-bearing capacity in case of a fire than the generally used steel beams. The authors—based on the relevant EU standards—performed load capacity calculations of three beams prepared from different materials under the influence of fire and analyzed the changes in the material properties. Then, they examined the possibility of reinforcing the beams with carbon fiber lamellae and proposed additional fire protection requirements. The test results not only proved the different degrees of fire resistance of various building materials in the event of a fire and after their reinforcement but also suggested the application of special technical, prevention and response measures for the safe storage of dangerous substances. The study outputs enable warehouse designers, operators and safety experts to ensure a higher fire safety level for chemical warehouses. Full article

This research investigated potential fire hazards originating in hidden areas of pressurized sections of aircrafts. The objective was to establish a laboratory-scale flammability test method to predict the behavior of fire propagation under real fire conditions. A confined fire apparatus (CFA) was designed and constructed, and several tests were conducted to better understand the involved mechanisms and their consequences and to estimate flame spreading in hidden-zone fires. The experimental facility and flame-spreading results obtained for a typical material involved in hidden fires, specifically a ceiling panel, were presented and discussed. The experimental facility consisted of a narrow passage where a fire was initiated using a burner on a specimen exposed to a controlled heat flux. Experiments were conducted in the absence of forced airflow. Flame spreading was estimated through visual monitoring of fire development or temperature measurements at specific locations in the specimen. Both methods yielded similar results. The flame spread velocity in relation to the imposed heat flux allowed for the estimation of the critical heat flux for spreading ${\dot{q}}_{sp,cr}^{″}$ and for ignition ${\dot{q}}_{ig,cr}^{″}$; the corresponding temperatures, T_s,min and T_ig; and the flame spread parameter Φ. Full article