Firing Line Research Articles

Survey and Investigation of Usage Status According to the Installation of Underground Fire Extinguisher Boxes in Korea’s Traditional Markets

Currently, traditional markets are structurally vulnerable to fire because of the dense concentration of old wooden buildings with tangled wires, such as aging facilities. Particularly in traditional markets, street vendors are usually disorderly located, and nearby roads are crowded due to illegal parking and vehicles stopping on the driveway. When a fire breaks out, it is difficult for the fire truck to enter, which is necessary to extinguish the fire in the early stages and prevent it from expanding into a large fire. With modernization, the number of fires is on the decline; however, fires in traditional markets continue to increase. According to the analysis of fire statistics from January to November 2023, 49 out of 819 fires in sales facilities were in traditional markets, accounting for 5.98% of fires in sales facilities. This is an increase of about 18 cases and an increase of 2.8% compared to fire statistics of about 3.19%, or 31 out of 972 fires at sales facilities as of 2017. Through these statistics, we can observe that the number of fires in sales facilities has decreased; however, the number of fires in traditional markets has increased. Traditional markets are at high risk of accidents due to the poor management of aging facilities and the lack of safety awareness among merchants. Specifically, in the event of a fire, which is likely to develop into a large fire in a short period due to structural problems, construction of high-density shopping malls, and mass loading of highly flammable goods, raising concerns about safety issues. As these problems have continued, the National Fire Agency has developed an emergency fire extinguisher box that could be buried underground in districts requiring fire prevention reinforcement, such as traditional markets and dosshouses. On January 20, 2018, and on May 2, 2018, ten units were first installed in the Seoul area. In this study, we conducted a survey on the current status of underground fire extinguishing systems boxed in traditional markets to identify the merchants' perceptions and analyze the operation of underground fire extinguishing systems boxed in the market.

Comparison of Different Models to Simulate Forest Fire Spread: A Case Study

With the development of computer technology, forest fire spread simulation using computers has gradually developed. According to the existing research on forest fire spread, the models established in various countries have typical regional characteristics. A fire spread model established in a specific region is only suitable for the local area, and there is still a great deal of uncertainty as to whether or not the established model is suitable for fire spread simulation for the same fuel in other regions. Although many fire spread models have been established, the fuel characteristics applicable to each model, such as the fuel loading, fuel moisture content, combustibility, etc., are not similar. It is necessary to evaluate the applicability of different fuel characteristics to different fire spread models. We combined ground investigation, historical data collection, model improvements, and statistical analysis to establish a multi-model forest fire spread simulation method (FIRER) that shows the burning time, perimeter, burning area, overlap area, and spread rate of fire sites. This method is a large-scale, high-resolution fire growth model based on fire spread in eight directions on a regular 30 m grid. This method could use any one of four different physical models (McArthur, Rothermel, FBP, and Wang Zhengfei (China)) for fire behavior. This method has an option to represent fire breaks from roads, rivers, and fire suppression. We can evaluate which model is more suitable in a specific area. This method was tested on a single historical lightning fire in the Daxing’an Mountains. Different scenarios were tested and compared: using each of the four fire behavior models, with fire breaks on or off, and with a single or suspected double fire ignition location of the historical fire. The results show that the Rothermel model is the best model in the simulation of the Hanma lightning fire; the overlap area is 5694.4 hm2. Meanwhile, the real fire area in FIRER is 5800.9 hm2; both the Kappa and Sørensen values exceed 0.8, providing high accuracy in fire spread simulations. FIRER performs well in the automatic identification of fire break zones and multiple ignited points. Compared with FARSITE, FIRER performs well in predicting accuracy. Compared with BehavePlus, FIRER also has advantages in simulating large-scale fire spread. However, the complex data preparation stage of FIRER means that FIRER still has great room for improvement. This research provides a practical basis for the comparison of the practicability and applicability of various fire spread models and provides more effective practical tools and a scientific basis for decision-making and the management of fighting forest fires.

Planting patterns in rubber agroforestry (Hevea brasiliensis) developed by the communities of Menggala Mas Village, Lampung Province, Indonesia

Abstract The agroforestry system provides important economic and ecological benefits for local communities, one of which is obtained from the application of planting patterns and plants species in it. This research aims to explain the planting pattern of rubber agroforestry developed by the community in Menggala Mas Village, Lampung Province, Indonesia. The approach in this research is qualitative. Data collection methods included observation, in-depth interviews, and documentation studies. The planting patterns of agroforestry system on their rubber plants were analysed. The research results showed that there are three agroforestry planting patterns implemented by the community, namely, alley cropping, trees along border and random mixture. The dominant combinations in alley cropping were rubber/karet (Hevea brasiliensis) – pulai (Alstonia scholaris) and rubber–mentru (Schima wallichii) – kayu afrika (Maesopsis eminii). The dominant combinations in trees along border were rubber–akasia (Acacia auriculiformis), rubber–jackfruit (Artocarpus heterophyllus) – cempedak (Artocarpus integer) and rubber–petai (Parkia speciosa) – jati (Tectona grandis). The dominant combinations in the random mixture were rubber–jengkol (Pithecellobium lobatum), rubber–petai–jengkol–akasia, rubber–jackfruit–cempedak, rubber–pulai–mengkudu (Morinda citrifolia L.) – jengkol and rubber–banana (Musa paradisiaca) – gadung (Dioscorea hispida) – sungkai (Peronema canescens Jack). Forty-one plant species were found. The local community wants to develop this planting pattern because the rubber agroforestry planting pattern can provide direct and indirect benefits such as a greater variety of plants which can increase their income; also, the products can be sold or consumed by the family, as a fence, fire break or barrier to other farmers’ land, can provide shade to reduce hot temperatures when farmers are working, and can reduce the risk of flooding and soil erosion to support soil and water conservation within the ‘Omou’ (garden/forest). The government and agricultural extension workers need to carry out regular guidance and outreach programmes regarding rubber agroforestry development strategies to increase public knowledge.

An Assessment on the Roles and Accountability of Adjacent Local Communities in Decentralized Forest Management System in Mufindi District, Iringa, Tanzania

Purpose: This study was undertaken in Ihang’ana Forest Reserve to provide an understanding of the roles and accountability of forest stakeholders in decentralized forest management for sustainability. The study was proposed specifically to assess decentralization of forest management approach by identifying the main stakeholders and examine their roles and methods used on management of the Ihang’ana Forest Reserve.
 Methodology: Multiple research methods were used for data collection which included literature reviews, structured questionnaires survey; institutional and key informant interviews, transect walks and observation and focus group discussions. The study adopted a mixed methods approach with simple and purposive sampling procedures. Quantitative data were analysed through SPSS with support of content analysis for qualitative data. Three villages adjacent to Ihang’ana forest were studied as target population Igeleke, Kibengu and Mwatasi with a total of 102 sampled respondents.
 Findings: The key findings of the study revealed that the major stakeholders in the management of Ihang’ana forest reserves were the local communities adjacent the forest reserves, the government and non-governmental organizations. The roles played by these stakeholders were guarding and patrolling done by local communities, education provision on forest management and facilities provision of seminars and workshops. The methods used to conserve and manage forest resources in Ihang’ana forest were afforestation, reforestation, agroforestry, destocking, implementation of enacted by-laws and the use of alternative energy. Several factors that led to effective management of the Ihang’ana Forest were implementation of forest by-laws, community inclusiveness, and strictness of the forest committee and application of deterrent penalties. The study concludes that local community participation in decentralized forest management bottom up approach is of paramount. The inclusiveness of the local community had led to effective management of the forest.
 Unique contribution to theory, practice and policy: The study recommends that, decentralized bottom-up approach forest management should be maintained for the forest sustainability. Also the central government should continue supporting the local communities in conservation activities of the forest, maintaining the existing fire breaks and timing for clearing the fire breaks is crucial.

Is the Forest Fire adjacent to St. Clair’s Waterfall Natural or Man-made?

Forest fires have been showing an increasing trend in Sri Lanka over the past few years. Previous studies proved that most of the forest fires in Sri Lanka were caused by human factors. The main objective of this study is to identify the causes of forest fires in close areas of St. Clair‘s fall, which is situated on the western slope of the Central Highlands and to investigate the impacts and measures to reduce forest fires. Primary data as well as secondary data were used for this study. Primary data was obtained through a questionnaire survey and focused group interviews from the study area of Hollyrood, Wattegoda, and Dewon GN Division. Twenty (20) households have been interviewed from the random sampling. Focused group interviews were held with the Nuwara Eliya Forest Conservation Department, Tea Estate companies and Thalawakele Police Station. Rainfall and temperature data were taken as secondary data for the period from 2010 to 2020 from the Department of Meteorology, Colombo. 83 respondents stated that forest fires occurs from January to April because of the high temperature and low rainfall recorded in these months. Patana grasslands are spared on the lower slopes of the left and right banks of waterfall area and plantation forest and Tea plantation have spread in the higher part of the slope. According to the Forest Department, the understory of Patana grassland and undergrowth for forest plantations are exposures to fire in this area. 96 respondents stated that forest fires are purposely started by the people to catch fish from the Kothmale Oya, build bonfire on the rock, and burn fish. Fires are generated through those flames. 63 stated that forest fires are done for ―jungle based feedings‖ for cattle herds by the people in the Thalawakele plantation settlement. They expect fresh grass to boom in the rainy seasons by setting fires in the dry season. 22 respondents stated that forest fires are purposely done for hunting purposes. Most of the fires occur on the left bank of the Kothmale Oya River. In order to prevent fires in this area, the fire breaks fire belt and such as corridors without and with floras are established as buffer zones on the right bank. This fire belt is maintain by Thalawakele Plantation Company. When a forest fire occurs, the Forest Department sends the SMS message to alert the community. Planting hana trees as a green belt can be recommended to reduce the occurrence of fires in this area. 
 Keywords: Central Highlands, Random sampling, Bonfire, Hana trees

Atmospheric turbulence observed during a fuel-bed-scale low-intensity surface fire

Abstract. The ambient atmospheric environment affects the growth and spread of wildland fires, whereas heat and moisture released from the fires and the reduction of the surface drag in the burned areas can significantly alter local atmospheric conditions. Observational studies on fire–atmosphere interactions have used instrumented towers to collect data during prescribed fires, but a few towers in an operational-scale burn plot (usually > 103 m2) have made it extremely challenging to capture the myriad of factors controlling fire–atmosphere interactions, many of which exhibit strong spatial variability. Here, we present analyses of atmospheric turbulence data collected using a 4 × 4 array of fast-response sonic anemometers during a fire experiment on a 10 m × 10 m burn plot. In addition to confirming some of the previous findings on atmospheric turbulence associated with low-intensity surface fires, our results revealed substantial heterogeneity in turbulent intensity and heat and momentum fluxes just above the combustion zone. Despite the small plot (100 m2), fire-induced atmospheric turbulence exhibited strong dependence on the downwind distance from the initial line fire and the relative position specific to the fire front as the surface fire spread through the burn plot. This result highlights the necessity for coupled atmosphere–fire behavior models to have 1–2 m grid spacing to resolve heterogeneities in fire–atmosphere interactions that operate on spatiotemporal scales relevant to atmospheric turbulence. The findings here have important implications for modeling smoke dispersion, as atmospheric dispersion characteristics in the vicinity of a wildland fire are directly affected by fire-induced turbulence.

Forest fires in the Indian Central Himalaya: major drivers, implications, and mitigation measures

ABSTRACT Forest fires pose a significant threat in the Central Himalaya due to both natural and human factors. This study investigates key drivers, consequences, and mitigation measures. Data on 2022 forest fire incidents, affected areas, and economic losses were collected from the State Forest Department, Dehradun, and analyzed using statistical methods. The 2022 forest fire areas were mapped using data from the USGS and NASA FIRMS portals, revealing highly sensitive zones in river valleys and mid-altitudes below 1800 m, covering 13% of the total forest area (approximately 40,000 ha). These regions primarily host monsoon deciduous and flammable pine forests. Recent years have witnessed a notable increase in fire frequency and intensity, attributed to warming river valleys, middle altitudes, and dry climate spells during the fire season. This pioneering study recommends risk reduction strategies, including managing dry pine leaves, forest replacement, constructing fire lines, and providing fire control training to rural communities. Adopting these measures can effectively mitigate the escalating threat of forest fires in the Central Himalaya.

Effects of a behavior-based safety observation program: Promoting safe behaviors and safety climate at work.

Behavior-based safety (BBS) programs promote coworkers observing and correcting each other's at-risk behaviors on site; the idea behind BBS programs is to create a cultural shift in a company where it is acceptable for coworkers to stop anyone, at any time, from working in an unsafe manner. The main objective of this study is to examine the impacts of a BBS observation program in the construction industry. The subject, an electrical contracting company, implemented the BBS program in January 2019. This study utilized multiple data sources: the company's incident data, BBS program report data, and surveys, including the Safety Climate Assessment Tool for Small Contractors. A total of 3,891 at-risk behaviors from the BBS reports, including 600 comments, and 141 survey responses were analyzed. The most frequently reported at-risk behavior was the line of fire, and the at-risk behaviors were often observed when workers conducted tasks, such as running or pulling wires, installing devices, and installing lights. The overall perception of safety climate was high, and the respondents reported that the safety climate had improved since the adoption of the BBS program. Overall, implementing the BBS program benefited in cultivating the company's collective safety climate. As a result of the BBS program, the company implemented better communication strategies for their safety meetings on the most frequently reported at-risk behaviors, replacing safety gears with higher quality ones, and redesigning online safety training to better reflect the identified tasks that were associated with more at-risk behaviors.

Generation of Smoke Dataset for Power Equipment and Study of Image Semantic Segmentation

Fire in power equipment has always been one of the main hazards of power equipment. Smoke detection and recognition have always been extremely important in power equipment, as they can provide early warning before a fire breaks out. Compared to relying on smoke concentration for recognition, image-based smoke recognition has the advantage of being unaffected by indoor and outdoor environments. This paper addresses the problems of limited smoke data, difficult labeling, and insufficient research on recognition algorithms in power systems. We propose using three-dimensional virtual technology to generate smoke and image masks and using environmental backgrounds such as HDR (high dynamic range imaging) lighting to realistically combine smoke and background. In addition, to address the characteristics of smoke in power equipment, a dual UNet model named DS-UNet is proposed. The model consists of a deep and a shallow network structure, which can effectively segment the details of smoke in power equipment and handle partial occlusion. Finally, DS-UNet is compared with other smoke segmentation networks with similar structures, and it demonstrates better smoke segmentation performance.

Fire traps in the wet subtropics: New perspectives from Hong Kong

Abstract Fires undermine efforts to restore degraded forests in the wet tropics and subtropics. Grasslands and shrublands established after fires are more fire susceptible than forests and tend to be set alight more often, creating a positive feedback loop that curbs succession (i.e. create a fire trap). Understanding the factors that underpin the strength of these fire traps could transform restoration programmes by identifying the steps needed to escape them. Fire traps are notoriously challenging to quantify because multiple factors influence fire occurrence and vegetation recovery. Here we used multi‐decadal satellite imagery from Landsat to create a 34‐year time series of burn areas and vegetation dynamics in wet subtropical Hong Kong. These dynamic maps were then used to characterise (1) the influence of successional stage on fire occurrence, having accounted for topographical and ignition source imbalances using neighbourhood analyses and entropy balancing (EBAL) weights, and (2) recovery time to the next successional stage by survival analysis with EBAL weights. Our analyses revealed that fire regimes in the wet subtropics are defined by strong fire‐vegetation feedbacks. Grasslands and shrublands were 20 and 9 times more susceptible to fires than forests in similar topographic positions. Human activities compounded these differences by disproportionally introducing more ignition sources to grasslands (2.3 times) and shrublands (2.0 times) than to forests. Burnt shrublands recovered to forests faster (19 years) than grasslands (40 years). Proximity to forest patches had strong positive effects on recovery rates, highlighting the importance of seed sources. Post‐fire recovery was faster on wetter northwest‐facing sites and valleys. Overall, topography strongly influenced recovery processes but hardly affected fire occurrence. Synthesis and applications. Our study provides the first quantification of fire trap processes in the wet subtropics, which provides new opportunities for evidence‐based fire suppression and post‐fire restoration. Our results suggest that (1) fire traps could be mitigated by fire suppression programmes as the traps are currently exacerbated by ignition source imbalance; (2) establishing green fire breaks represents an effective fire suppression measure in the wet subtropics; and (3) active restoration could target areas where models predict sluggish post‐fire natural regeneration.

In the line of fire: Analyzing burning impacts on air pollution and air quality in an Amazonian city, Brazil

Brazil is grappling with escalating wildfire incidents, particularly in the ecotone region of Cerrado-Amazon, attributed to climate change and anthropogenic factors. These wildfires significantly impact air quality, posing health and environmental risks to the population. This study aimed to assess the influence of wildfires on air quality in Sinop, a city located in Northern Mato Grosso, Brazil. The primary focus was on understanding the behavior of air pollutants during and after wildfire events. Air quality data were obtained from modeling dataset, while meteorological data from ground-based monitoring, and wildfire data from the National Institute of Spatial Research of Brazil. Statistical analyses were employed to investigate pollutant variations and their relationships with meteorological parameters and wildfire intensity indicators. The study revealed a significant impact of wildfires on pollutant concentrations, with ozone levels rising immediately after fires and remaining elevated for several days. The particulate matter (PM2.5 and PM10) concentrations increased a few days after fire events. Fire radiative power (FRP) correlated with O3 levels, suggesting it is an intensity indicator. Temperature exhibited a consistent positive correlation with all pollutants, highlighting its role in pollutant dynamics. The findings underscore the multifaceted relationship between wildfires, meteorological conditions, and pollutant concentrations pointing to the importance of holistic air quality management strategies in fire-prone regions. Such studies are crucial for guiding environmental policies, safeguarding public health, and advancing scientific understanding in the face of escalating wildfire challenges.

Formation and movement of multiple fire whirls

This paper presents an experimental study on the formation and movement characteristics of multiple fire whirls on the line fire under different slope angles (θ). Experiments were performed in a rotating screen facility with independently controlled heat release rate per unit length (Q˙l) and shear wind speed (us). The evolution of the line fire under different shear wind speeds and slope angles involved six regimes, including free line fire, interacting line fire, moving fire whirls, stationary fire whirls, stationary unstable fire whirls, and moving unstable fire whirls. The critical us for the formation and movement of fire whirls decreased roughly with increasing θ. The moving fire whirl would become stationary when us reached the critical value, which may be explained by the balance between the buoyancy-induced velocity and us. A correlation was proposed for predicting the critical shear wind speed of the stationary fire whirl on the sloped surface. The spacing between adjacent fire whirls increased steadily with us under various θ, and the dimensionless spacing depended on the dimensionless us by the 0.5 power law for all θ. The formation frequency of the moving fire whirl increased steadily with θ, and was inversely proportional to us. The variation of the average moving speed of the fire whirls with us differed among different θ. The average moving speed decreased steadily with us for the relatively low slope angles (θ ≤ 15°), and increased first and then decreased with us for the relatively large slope angles (θ ≥ 20°). The steady decrease of the flame height with the large us was associated with the apparent bulge structure at the flame tip, and the critical us for the occurrence of the bulge structure decreased at the relatively large slope angles (θ ≥ 20°).

Supplemental Material for Leaders Laughing in the Line of Fire: An Emotional Aperture Perspective on Leader Laughter in Response to Critical Questions

Supplemental Material for Leaders Laughing in the Line of Fire: An Emotional Aperture Perspective on Leader Laughter in Response to Critical Questions

Assessment of spatial distribution of lead in soils around an active military shooting range

Abstract In this study, the extent of Pb contamination around an active military shooting range is re-assessed to ascertain current contamination status comparatively to data’s reported 20 years ago. This is because lead bullet disintegration and mobility takes several years and extensively affects levels of soil-Pb contamination. A total of 120 topsoil samples were collected within the impact area (front) and non-impact area (back) for Pb determination. High concentrations of Pb were found at impact berm both front (28940±2996 μg/g) and back (775±128 μg/g). Spatial distribution of contamination reflects the distances from berm. Soil-Pb contamination around non-impact area was notable at back berm through to 100 m distance with significant difference in Pb, Cr, Ni and Zn levels. Concentration of Pb at berm was observed to have increase five-fold over a period of about twenty years from previous study with accumulation factor of about 1000. Principal component analysis PCA indicated 67 % of total metal load of range soil was majorly from impact areas of the berm. The correspondence analysis relay plot shows pollution order of Pb > Ni > Cd > Cr > Zn > Cu. This confirms soil contamination especially around the impact area, i.e. impact berm and firing lines and non-impact area at 0 m, 10 m, 50 m and 100 m. Environmental consequence of high soil-Pb levels within the range especially non-impact areas utilized for farming activities will leave much to desire. Hence, extensive and continuous monitoring is needed. However, remediation through appropriate soil washing technique could reduce Pb levels and improve soil condition regardless of age.

Study on combustion and flame merging characteristics of two n-heptane line fires under wind speed, spacing, and groove width

This paper studied the effects of wind speed, spacing and groove width on the combustion and flame merging characteristics of two n-heptane line fires. The experimental results show that the range of intermittent merging stage will increase with groove width; the greater the wind speed, the greater the probability of merging. At the non-merging stage, the influence of wind speed on the flame merging probability can be ignored. Under the influence of wind speed, mass loss rate per unit area, ??, of the downstream pool fire is greater than that of the upstream pool fire, at the stages of fully merging and intermittent merging. While when the flame spacing increases to the non-merging stage, ?? of the upstream pool fire begins to be gradually greater than that of the downstream pool fire. On the other hand, the downstream flame ?? increases firstly and then decreases, while the upstream flame ?? shows an increasing trend, with spacing distance. The smaller the groove width, the greater the value of ?". When the spacing is 0, ?? is the smallest. It is found that with the increase of spacing, the flame length under all tested conditions increases firstly and then decreases, and the flame inclination angle decreases firstly and then increases.

A Study on Setting the Optimal Installation Location considering the Air-conditioning Environment of the MLCC Factory Clean Room and the Performance of the Smoke Detector

A circulating airflow was generated inside the clean room of an MLCC factory. This airflow affects the movement of combustion products (such as heat, smoke, and toxic gases) when a fire breaks out, and there is a risk of delaying the time required to detect the fire. In this study, testing, adjusting, and balancing were conducted for an actual MLCC plant clean room to analyze the effect of the circulating airflow inside the clean room during fire spread. In addition, the optimal detector location that reduces the time required for smoke detection was determined using a fire simulation program.

A model to predict maximum tangential wind velocity in laboratory-scale fire whirls without flames in a crosswind

Fire whirls cause strong wind damage in large outdoor fires such as wildland fires and urban fires. A model to predict the maximum tangential wind velocity in laboratory-scale fire whirls without flames in a crosswind is developed based on a generation mechanism and the properties of the fire whirls. The model also predicts the radii of the fire whirls and the crosswind speed when they occur. The fire whirls modeled are those with large circulation and large radii, that is, large intense fire whirls. These fire whirls occur and remain downwind of a fire line placed perpendicular to the crosswind under a low crosswind speed and a high heat release rate (HRR). The model agrees well with the experimental results.

Spatio-Temporal Dynamics of Forest Fires in Poland and Consequences for Fire Protection Systems: Seeking a Balance between Efficiency and Costs

An important issue from the forest fire protection system perspective is forecasting fires and maintaining a high readiness of firefighting units at a low cost. In Poland, the level of fire protection is defined by the degree of forest fire risk, based on forecasts made for 1 March to 30 September, i.e., the risk period (the so-called fire season). In this paper, based on classical statistical and spatial analysis, we positively verify the research hypothesis that the fire season in Poland changes in terms of start and end dates depending on the region. We therefore propose a modification to the forecasting period, adapted to local conditions and calculated annually on the basis of the previous period. Then, using network analysis, we negatively verify the hypothesis that the size of the burned area is related to the distance from fire brigades, which proves that the reasons for such a differentiation in the number of fires should be sought elsewhere than in the system used for allocating fire units. On the basis of cluster analysis, attention is drawn to areas where large fires break out more often.

Integrating dynamic wildland fire position input with a community fire spread simulation: A case study of the 2018 Camp Fire

Wildland fire simulation models can be used to inform wildfire risk assessment and mitigation strategies. However, existing models tend to simulate fire spread only inside the wildland or the wildland-urban interface (WUI) communities, but not in both. As a result, there is a need to integrate methodologies to enable seamless simulations of events that ignite in the wildland and continue spreading both across the wildland and inside WUI communities. This paper investigates a systematic methodology to provide a WUI fire spread model with the capacity to assimilate dynamic wildland fire position inputs. The paper uses the streamlined wildland-urban interface fire tracing (SWUIFT) model to simulate WUI fire spread, weather radar data to track the fire line inside the wildland, and the 2018 Camp Fire event as a case study. The work proposes and evaluates a methodology based on a ‘Three-Domain Solution’ (Wildland, Transition, Community) for a smooth fire transition between wildland and community settings. Alternative approaches are examined to describe the boundaries of a Community Domain for simulation purposes. Existing WUI definitions are studied, and considering the analysis results, a non-WUI neighborhood-based housing density (NBHD) method is proposed. This work establishes a systematic approach for a unified wildland-WUI fire simulation.

Varying Heat Release Rates per Unit Area – The Impact in Underground Mines

Abstract The fire behaviour and smoke behaviour of a fire in an underground mine will be largely dictated by the heat release rate of the fire. The heat release rate per unit area is generally the output from small-scale fire experiments and can be applied for larger objects with varying surface area. This paper studies the impact of varying heat release rate per unit area for fires in materials and substances typically found underground. Data from earlier fire experiments were analysed and discussed, and several different heat release rate curves and flame spread velocities for various fuel components were developed and discussed. It was found that the hydraulic hose presented the highest peak heat release rate per unit area of the solid fuel items, followed by the low-voltage cable, cab interior, and tyre in descending order. The increase in the peak heat release rate was highest for the highest incident heat flux levels, representative for scenarios underneath a mining vehicle. The heat release rate per unit area of pool fires underneath a vehicle is significantly higher than a corresponding free burning case - attributed to the higher incident heat flux – but a gravel surface underneath a pool fire will reduce the heat release rate considerably. Line fires in larger bundles of electrical cables were modelled and found to attain the peak flame spread velocity more rapidly compared with a fire in hydraulic hoses. This was caused by the higher heat release rate of the initial fire and ignited segments in the electrical cable case.