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Around one billion people (UN 2012) worldwide live in informal settlements (also known commonly by the more derogatory names of slums, ghettos, shantytowns etc.), and these areas are often ravaged by fires. This paper presents an overview of the problem of fires in informal settlements and provides an understanding of fire engineering such that pro...
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... items within the enclosure to ignite and the fire to spread. Once the hot layer of gas that builds up in the enclosure is deep enough that it extends down to encounter objects such as furniture and carpets in a room it causes all the objects in an entire enclosure to spontaneously combust. This is the phenomena known as flashover, as noted in Fig. 2, and it is associated with a rapid increase in temperature as energy is released. If the rate of combustion is limited by the amount of available oxygen the fire is referred to as a ventilation controlled fire (the blue line on Fig. 3) whereas when the amount of fuel available for combustion limits the burning rate it is referred to as ...
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... The materials used had an important influence on the fire load estimations and in the fire dynamics observed. Although previous research in IS has shown that the fire load can be extremely variable [20,[59][60][61], in IS most of the fire load was mostly associated with the contents. However, in this case the shelter alone accounted for 1500 MJ/ m 2 , which is equivalent to approximately 33 l of petrol per m 2 . ...
According to the UN Refugee Agency, roughly 980,000 people live in the Cox’s Bazar region in Bangladesh, making it the largest and most densely populated refugee camp in the world. The number of fires in this settlement rapidly increased in 2021. On 22 March, a large fire event occurred, where 15 fatalities and 560 injuries were reported, and more than 9500 homes were affected leaving 45,000 homeless. This work seeks to reconstruct this incident based on firefighters’ statements, information found in the media, and satellite imagery. The study shows that (a) the fire spread extremely fast, with linear spread rates between 79 and 310 m/h and an average areal spread rate of 92,850 m ² /h estimated, (b) the firefighters performed two main operations, firefighting and the creation of fire barriers, (c) the residents self-evacuated, deciding when and where to evacuate, and (d) the residents’ actions were similar to what has been observed in residential fires, with several people mentioning looking for missing family members. Fire spread is analogous to wildland fires where conflagrations spread across large areas of combustible material. This work can be used in planning for future large-scale fire incidents in tented camps, and proactively seeking ways of mitigating their impact. This is the first detailed documentation of such a large-scale refugee camp incident in the academic literature.
... Residents may take their belongings with them when evacuating, or place their belongings (including furniture) on roads far from fires for protection where it was supposed to be firebreak. It was also reported residents joined firefighting activities to protect their dwellings [11,98,99,190]. Detailed study was performed for the informal settlement fires in El Pochote, San Jose, Costa Rica in 2019. Seventy minutes of the brigades' and residents' action was investigated via video footage and interviews. ...
Large outdoor fires such as wildfires, wildland urban interface (WUI) fires, urban fires, and informal settlement fires have received increased attention in recent years. In order to develop effective emergency plans to protect people from threats associated with these events, it is important to understand human behavior in large outdoor fires. This paper provides a broad review of existing empirical research and modeling efforts on human behavior in large outdoor fires to provide researchers and practitioners with reference material. In this paper, first, the various methodologies on how information on human behavior is collected from large outdoor fire events is reviewed. Next, available empirical literature that synthesized this information from various survey techniques to paint a picture of the human behavior from large outdoor fire disasters is summarized. The review then moves into how evacuation models have been developed to potentially predict human behavior during various large outdoor fire disasters, and how these models are dependent on the data collection methodologies above. This review concludes with emerging issues and challenges.
The review found that interviews and surveys taken from pre-and post-disasters have greatly advanced the understanding of human behavior in large outdoor fires. Yet, past modelling efforts were mainly limited to traffic modelling approaches. The current research direction has shifted to the use of Artificial intelligence (AI) and Geographic Information System (GIS) methods to model evacuation behavior coupled with fire spread. Most of the reviewed research was concerned with wildland-urban interface (WUI) fires, due in part to the greater number of disasters across the globe. As there were less informal settlement fire and urban fire disaster studies in the literature, much more work on those two fire types is needed in the future. There also needs to be broader comparison to all large outdoor fire types to potentially harness similarities amongst all of these types of disasters
... Different from the construction materials and structures of South African shacks, UVDs are usually built of bricks or concrete with multiple compartments and storeys. For security reasons, some shacks have no or very small windows [15], but the complexity of openings (ventilations) condition in UVDs will significantly change the stage of compartment fire and affect the spread of fire to surrounding dwellings. It was found that the vent size and geometry have a considerable impact on the vertical temperature and oxygen concentration profiles [16]. ...
As the most common informal settlement in the far east, urban villages are subject to very high fire risks due to relatively poor fire safety conditions and inefficient management. However, no experimental research has been conducted on the fire dynamics of Chinese urban village dwellings to date despite their own characteristics. In this work, two real-scale experiments with different opening conditions (both window and door open or closed) were performed in two urban village dwellings located in Lai’an County, with identical dimensions of 4.4 (length) × 3.3 (width) × 2.8 (height) m3 and a fuel load of 407 MJ/m2. The important parameters, in terms of inside gas temperatures, burning behavior, gas flow velocities at the opening, total heat release rate and flame behavior, were measured or estimated. It was found that the effect of the opening condition has a significant influence on the flashover occurrence, smoke movement and temperature distributions. In particular, with the window and door closed, the compartment fire self-extinguished, but the breakage and fallout of glass panels dramatically changed the fire dynamics from smouldering combustion to a post-flashover compartment fire. The interaction between enclosure fire dynamics and the fallout of window and door was then established. The experimental results would provide basic data and perception for further numerical or analytical analysis concerning the fire safety of urban village dwellings.
... 3 Another three million households live in "backyard shacks" in low-income formal areas. In Cape Town, fires occur almost every day (Walls and Zweig 2017), and the city has by the far the highest recorded number of informal settlement fires in South Africa (Zweig et al. 2018;). However, the national data may be incomplete for other large metropolitan areas (for example, Johannesburg, Ekurhuleni, and Tshwane), which may experience just as many, or possibly even more fires. ...
... In January 2013, for example, a fire in Khayalitsha (one of Cape Town's largest low-income areas) left five dead and 4000 homeless (Sacks 2013). A fire in Masiphumele in December 2015 killed one person and left 1000 homeless (Walls and Zweig 2017), while the fire in November 2020 left two dead and displaced 4000 (Pitt and O'Regan 2020). The notorious fire in Imizamo Yethu in 2017 killed four people, destroyed 2194 dwellings, and left almost 10,000 people homeless ). ...
... Dwellings in informal settlements and backyards are usually built and insulated using flammable materials like wood, plastic, and cardboard. At the same time, people rely on cheap but hazardous sources of energy and light, such as candles, paraffin stoves, and open fires (Pharoah 2009;Walls and Zweig 2017;Cicione et al. 2019). Fires are also frequently caused by electrical faults owing to overloaded plug points and illegal electricity connections (Morrissey and Taylor 2006;Zweig et al. 2018;Walls, Eksteen et al. 2019). ...
This article presents the findings of a pilot project to test the large-scale rollout of smoke alarms in an informal community in Cape Town, South Africa. The work provides novel insight into the effectiveness and challenges associated with using smoke detectors in low-income communities. Technical details and detector considerations are also provided that will assist in enhancing future interventions. The project installed 1200 smoke detection devices in TRA informal settlement in the suburb of Wallacedene, in the City of Cape Town, and monitored their effectiveness for a period of 12 months. The monitoring showed that there were 11 real activations, where the presence of the devices likely saved lives and homes. The project also identified a series of challenges, especially in relation to nuisance alarms, where everyday household emissions, dust, and insect ingress caused false alarms, leading some participants to uninstall devices. The findings of the pilot study suggest that although smoke detectors could provide a valuable tool for reducing the frequency and impact of informal settlement fires in South Africa and elsewhere, they need to be adapted to meet the specific needs and conditions encountered in informal dwellings. Modifications, such as adjusting device sensitivity, preventing dust and insect ingress and tailoring devices to everyday conditions, will be essential to make smoke alarms more suitable and effective in the future. Smoke alarms could become an important component of low-income community fire safety if such challenges can be addressed.
... As a result of unbalanced urbanization, informal settlements often appear in low-and middle-income countries and are home to approximately one billion people globally [3,4]. These settlements are often ravaged by fires [5] due to relatively poor fire protection and management, high settlement densities, and extensively distributed combustible materials [2,6]. For example, on 11th March 2017, a large fire ravaged the Imizamo Yethu informal settlement in Cape Town, South Africa, causing 2194 informal dwellings to be burnt down, and there were four casualties, and more than 9700 people were left homeless [7]; On 14th October 2021, the worst fire in the 25 years in Taiwan occurred in the informal ''Ghost Building'' in Kaohsiung City, causing 46 deaths [8]. ...
As the largest developing country, China has a large number of informal settlements threatened by fire, including shanty towns, urban villages, group rented houses, prefabricated houses and ethnic minority traditional settlements, especially for some ethnic minority traditional settlements in the southwestern region. However, the studies on fire safety of Chinese informal settlements are very limited. This paper aims to obtain deeper insight into the features of these settlements and a detailed understanding of ethnic minority traditional settlement fires. In order to achieve the goal, a comprehensive perspective of the characteristics of such informal settlements, detailed information on 1244 ethnic minority traditional settlements in southwest China was investigated, including ethnic minority grouping, population, structural characteristics of dwellings, construction materials, slope and altitude of settlements. It was found that the stilted building style is the primary structure characteristic accounting for 69.7% of all structures of dwellings; approximately 60% of the settlements use wood as building material; the average slope is 20° which can accelerate the fire spread; and the average altitude is 1136 m which may make fire rescue difficult. Meanwhile, to systematically understand the effect of different fire influencing factors on ethnic minority traditional settlement fires and provide analytical methods for such informal settlement fires, two case studies were conducted using Geographic Information System (GIS) analysis to investigate the important parameters for fire spread behavior in these settlements. It was found that the slope gradient for Wengding village is less than 8.5°; the critical separation distance in Wengding and Shangri-La is greater than 3.3 m; and the primary factors for quick fire spread in the ethnic minority settlements may include non-conforming fire-fighting facilities, close house proximity and extensive combustible building materials.
... The RSDs are geometrically scaled according to respective geometric ratios, and the vents (doors and windows) are scaled based on ventilation factor scaling as used by Bryner, et al. [14]. A fire load density in an informal settlement could range from 370 MJ/m 2 to 3000 MJ/m 2 [15]. An average fuel load of 780 MJ/m 2 was used in the FSE, which gave a total HRR of 10250 kW. ...
Informal settlement dwellings (ISDs) house approximately one billion people in the developing world and this number is expected to double by the year 2030. Contemporary research on ISD fires has focused on understanding the fire dynamics within individual dwellings (micro-scale) and fire spread in settlements consisting of multiple dwellings (macro-scale). This paper aims to do two primary things: investigate if scaling methods that were derived for compartments with thermally thick boundaries can be applied to ISDs (compartments with thermally thin boundaries), and if they can adequately represent the most important phenomena associated with full-scale ISD fires; and demonstrate Fire Dynamics Simulator (FDS) simulations against the Reduced-Scale Experiments (RSEs) conducted in this work by comparing the simulation results and fire behaviour to that of the RSEs. In this work, five RSEs—a 1⁄15 scale, 1⁄10 scale, 1⁄7.5 scale, 1⁄5 scale and a 1⁄4 scale experiment—were conducted. The RSEs are based on the full-scale ISD fire experiments done by Cicione, et al., and were scaled using parameters such as Heat Release Rate (HRR) of the fuel packages, ventilation factors and the overall geometry of the dwellings. The full-scale experiment’s geometry is based on the ISO 9705 compartment fire test. Temperatures, heat fluxes and flame heights for each of the RSEs were recorded and analysed to determine the correlation of the fire behaviour between the RSEs and the full-scale experiments. The results from this study suggest that reduced-scale modeling with RSE models of 1/4 scale and 1/5 scale can be used to replicate an ISD fire with a reasonable level of certainty, depending on the parameter being studied. Limitations and challenges associated with the scaling methods employed are discussed, as not all fire phenomena can be accurately captured.
... Spatial metrics can be used to describe morphological characteristics within the urban environment (Herold, Liu, & Clarke, 2003) and can be used to challenge or confirm assertions such as " Fires spread rapidly through such densely populated areas" (Walls & Zweig, 2017), "Fires can start and spread easily in such locations due to a number of factors, including: ….high building density…" (Twigg, Christie, Haworth, Osuteye, & Skarlatidou, 2017), and "…easily spread from one dwelling to another based on the close proximity of adjacent houses…." (Walls & Zweig, 2017). ...
... Spatial metrics can be used to describe morphological characteristics within the urban environment (Herold, Liu, & Clarke, 2003) and can be used to challenge or confirm assertions such as " Fires spread rapidly through such densely populated areas" (Walls & Zweig, 2017), "Fires can start and spread easily in such locations due to a number of factors, including: ….high building density…" (Twigg, Christie, Haworth, Osuteye, & Skarlatidou, 2017), and "…easily spread from one dwelling to another based on the close proximity of adjacent houses…." (Walls & Zweig, 2017). Thus from the perspective of fire spread, spatial metrics which consider dwelling density and proximity can be analysed against areas where historic fires have occurred. ...
... A lower average ENN and standard deviation of ENN was found for the Fire Extent Areas when compared with the Potential Fire Areas. Contrary to generalised statement around density (Twigg et al., 2017;Walls & Zweig, 2017) the dwelling density does not appear to be a good indicator of fire spread risk, but edge density in the Fire Extent Areas Fig. 10. a. Number of fire incidents and b. ...
Fires in informal settlements are devastating to residents of these precarious urban environments. This paper highlights the use of spatial metrics and wind speed and direction for fire spread risk identification for informal settlement fires in Cape Town. Data on: fire incidents, dwelling footprints, and the wind conditions during a fire, are analysed both together and separately. Fire incidence data analysed with wind data reveals that the majority of fires occur in December with the most destructive fires taking place during moderate wind conditions. At higher wind speeds, the distance between the flame and adjacent dwelling is not reduced but the flame height is, leading to reduced radiation. Also, convective cooling at higher wind speeds increases the time-to-ignition and flashover of the adjacent dwelling. Analysis of dwelling data reveals that the average and standard deviation of distance to the first nearest neighbour together with edge density can be used to identify areas at risk of fire spread. A threshold approach using the distance to a dwelling's first nearest neighbour together with the range in distance from the dwelling's first to third nearest neighbours allow for the identification of specific dwellings within a settlement which are at risk of fire spread.
... It can be extinguished by removing the chain reaction of either one or all these substances. Either removing heat/fire by cooling, reduce the level of oxygen called smothering or by a starving method where the source of fuel and the oxidizer can be separated [1], [2]. However, the gas type of fire suppression systems only can perform by smothering or cooling methods. ...
The historical development of fire suppression technology evolved in the 1930s since the application of Halons as a fire extinguishing agent. The fire may cause tremendous losses to organizations. It affects the chain of businesses and the stability of the economic growth of a country. The key issues of greenhouse effects and safety and health as well contributes to the sudden change of the technology of fire extinguishing systems. The establishment of the Montreal Protocol and Kyoto Protocols controls the producers to develop, supply and use of environmentally hazardous gasses worldwide. Hence, promote global sustainable for upcoming generations. This paper is highlighting the reasons gas type fire extinguishing agents extensively used substituting conventional methods against fire. The fundamental equations of Ozone Depleting Potential and Global Warming Potential were properly discussed to show how severe these gasses exposed to the environment. The effectiveness of these gases as a clean agent in extinguishing the fire may convince prospect users to carry out the decision of changes. Potential extinguishing agents will be deliberated to investigate their needs as new fire suppression agents. It will be then to be suggested and recommended for further studies.
... It is well known that ISDs are constructed from a variety of materials [29], and that no two dwellings are the same. The material used does not only vary from dwelling to dwelling, but also The maximum transient HRR of the timber used is around 200 kW/m 2 , with a stable HRR of 100-150 kW/m 2 , as determined by a cone calorimeter [23]. ...
... It is well known that ISDs are constructed from a variety of materials [29], and that no two dwellings are the same. The material used does not only vary from dwelling to dwelling, but also from settlement to settlement. ...
Large conflagrations of informal settlements occur regularly, leaving thousands of people homeless daily and taking tens of thousands of lives annually. Over the past few years, a large amount of data has been collected from a number of full-scale informal settlement fire experiments. This paper uses that data with a semi-probabilistic fire model previously proposed by the authors, to illustrate the potential applications of the fire spread method proposed. The current model is benchmarked against a 20-dwelling full-scale informal settlement fire experiment, and the effects of the (a) ignition criteria, (b) wind direction, and (c) wind speeds on the predicted fire spread rates are investigated through the use of a parametric study. Colour maps of the fire spread rates and patterns are then used to visually interpret the effects of different types of fire scenarios and fire breaks. Finally, the fire spread capability within BRISK is used to derive a linear equation for the potential fire spread rate as a function of the settlement spatial metrics (e.g., density and distance to nearest neighbour). To further illustrate the potential application of this work, the fire spread rate equation is then applied across the whole of Cape Town, South Africa, to show the 10 informal settlement areas most at "risk" of large conflagrations.
... Recent studies have look at the understanding the fire dynamics within ISDs and understanding the fire spread between ISDs [3,[7][8][9] with the hope that the findings can assist local authorities when implementing fire spread interventions and also better their understanding of informal settlement fires. Cicione et al. [6] investigated the effect of cladding materials (steel cladding versus timber cladding) on fire spread based on two full-scale single ISD experiments. ...
Globally, the number of informal settlement dwellings are increasing rapidly; these areas are often associated with numerous large fires. Unfortunately, until recently, very little research has been focused on informal settlement fire issues leaving any attempts to improve their fire safety lacking the evidence base to support effective-decision making. However, over the past 4 years, a limited number of researchers have looked at better understanding these fires through full-scale experimentation and numerical modelling; starting to provide the necessary evidence base and future research directions. It is with this background in mind that this paper seeks to provide a more fundamental understanding of the effect of dwelling separation distance on informal settlement fire spread based on full-scale experiments and analytical equations. In this paper two full-scale experiments were conducted. Both experiments consisted of multiple dwellings, with the main difference between the experiments being the separation distance. Fire spread times, heat release rates, door and window flow velocities, ceiling temperatures and incident heat fluxes were recorded and are reported for both experiments. Theoretical neutral planes are derived and compared to the experimental neutral planes, which show relatively good correlation. The paper continues by calculating the expected incident radiation and time-to-ignition, using the flux-time product method, of the two fire scenarios (i.e., the two experiments) through means of analytical equations, and these findings are compared to the experimental results. Through configuration factors, the paper shows the effect of separation distance, dwelling height and dwelling length on the times-to-ignition, where it is clear that the heat flux received by an adjacent dwelling decrease approximately exponentially as the distance between dwellings increases, and consequently, the time-to-ignition increases exponentially as the separation distance between dwellings increases.
