A fire or wild forest fire is a fire in a combustible vegetation area that occurs in rural or rural areas. Depending on the type of vegetation where it occurs, flames can also be classified more specifically as fire brush , fire bush , desert flame , forest , grass fire , fire hill , peat fire , vegetation flame , and veld fire .
Fossil charcoal shows that forest fires started soon after the emergence of terrestrial plants 420 million years ago. Wildfire incidents throughout the history of terrestrial life invite allegations that fire must have had an evolutionary impact on most ecosystem flora and fauna. The Earth is a planet that is intrinsically flammable because of the closure of carbon-rich vegetation, seasonal dry climates, atmospheric oxygen, and flames and widespread volcanic flaring.
Wildfires can be characterized in terms of the causes of ignition, their physical properties, the presence of flammable materials, and the effects of weather on fire. Wildfires can cause damage to property and human life, but they have many beneficial effects on native vegetation, animals and ecosystems that have evolved by fire. Many plant species rely on fire effects for growth and reproduction. However, fires in ecosystems where wild fire is rare or where non-native vegetation has been encroached can have a negative ecological effect. Wildfire and severity result from a combination of factors such as available fuel, physical arrangement, and weather. Analysis of historical data on meteorologists and national fire records in western North America shows the primacy of climate in encouraging large regional fires through a wet period that creates fuel or large drought and warming that prolongs conducive fires.
Fire prevention, detection, and suppression strategies have varied over the years. One common and cheap technique is controlled combustion: allowing or even lighting a smaller fire to minimize the amount of combustible material available for fire potential. Vegetation can be burned at regular intervals to maintain a high species diversity and often burn surface fuel to limit fuel accumulation. The use of fire in the wilderness is the cheapest and most ecologically appropriate policy for many forests. Fuel can also be eliminated by felling, but fuel maintenance and thinning do not affect the behavior of severe fires when in extreme weather conditions. Wildfire itself was reportedly "the most effective treatment to reduce the extent of fire spread, intensity of fire lines, fire length, and heat per unit area" according to Jan Van Wagtendonk, a biologist at Yellowstone Field Station. Building codes in fire prone areas usually require that structures constructed from refractory materials and maintained space are maintained by cleaning up combustible materials within the specified range of structures.
Video Wildfire
Cause
The four major natural causes of forest fires are:
- lightning
- spontaneous combustion
- volcanic eruptions
The most common direct human causes of forest fires include burning, discarded cigarettes, electric arcs (as detected by arc mapping), and sparks from equipment. The ignition of wild forest fires through contact with shrapnel of hot bullets is also possible under the right conditions. Forest fires can also start in shifting cultivation communities, where land cleared quickly and planted until the soil loses fertility, and felling and burning. Logged forest areas encourage the dominance of flammable grasses, and abandoned logging roads overgrown by vegetation can act as fire corridors. The annual prairie fires in southern Vietnam came from the destruction of forest areas by US military herbicides, explosives, and the clearance of mechanical land and burning operations during the Vietnam War.
The most common causes of forest fire vary around the world. In Canada and northwest China, lightning operates as a major source of ignition. In other parts of the world, human involvement is a major contributor. In Africa, Central America, Fiji, Mexico, New Zealand, South America, and Southeast Asia, forest fires can be attributed to human activities such as agriculture, livestock, and land conversion. In China and in the Mediterranean Basin, human carelessness is a major cause of forest fires. In the United States and Australia, the source of forest fires can be traced both to lightning strikes and to human activities (such as machine splashes, discarded cigarette butts, or burning). Coal fire burns thousands worldwide, such as in Burning Mountain, New South Wales; Centralia, Pennsylvania; and some coal fires in China. They can also light up abruptly and ignite nearby combustible materials.
Maps Wildfire
Spread
The spread of forest fires varies by flammable materials, their vertical settings and water content, and weather conditions. Fuel arrangements and densities are partially regulated by topography, since the shape of the land determines factors such as available sunlight and water for plant growth. Overall, the type of fire can generally be characterized by their fuel as follows: Fire
- Land is fed by underground roots, duffs and other buried organic materials. This type of fuel is very susceptible to ignition because of spotting. Land fires are usually burning with fire, and can burn slowly for days to months, such as peat fires in Kalimantan and East Sumatra, Indonesia, resulting from riceland-making projects that are accidentally drained and drained peat. Fire
- Crawling or the surface is triggered by lowland vegetation on the forest floor such as leaves and litter, debris, grass, and low shrubs. This type of fire often burns at a relatively lower temperature than the crown flame (less than 400 Â ° C (752 Â ° F)) and can spread at slow speeds, although steep slopes and winds can accelerate the spreading rate.
- Stairs fire consumes material between low-level vegetation and tree canopy, such as small trees, falling logs, and vines. Kudzu, Old World climbing rods, and other invasive crops that cut down trees can also encourage stair fires.
- Crown , canopy , or fire air burns suspended materials at the canopy level, such as tall trees, plants creeping, and moss. The flame ignition, called crowning, depends on the density of the suspended material, the height of the canopy, the continuity of the canopy, the sufficient surface and the fire ladder, the moisture content of the vegetation, and the weather conditions during the blaze. Standing in place of a fire illuminated by humans can spread to the Amazon rainforest, destroying ecosystems unsuitable for hot or dry conditions.
Physical properties
Forest fires occur when all necessary elements of a fire triangle join together in a vulnerable area: the ignition source is brought into contact with combustible material such as vegetation, which is exposed to sufficient heat and has sufficient oxygen supply from the ambient air. High water levels usually prevent ignition and slow propagation, as higher temperatures are required to evaporate any water in the material and heat the material to its point of fire. The dense forest usually provides more shade, resulting in lower environmental temperatures and greater moisture, and is therefore less susceptible to forest fires. Less dense materials such as grass and leaves are more easily ignited because they contain less water than solid materials such as branches and stems. Plants continue to lose water with evapotranspiration, but water loss is usually offset by water absorbed from soil, moisture, or rain. When this balance is not maintained, the plant dries out and therefore is more flammable, often a consequence of drought.
The wild flame is a part that maintains a continuous burning of burning, where unburned material fills the active fire, or a burning transition between unburnt and burning material. As it approaches, fire heats air and wood material through convection and heat radiation. First, the wood is dried because the water is evaporated at a temperature of 100 ° C (212 ° F). Furthermore, wood pyrolysis at 230 ° C (450 ° F) releases combustible gas. Finally, the wood can smolder at 380 ° C (720 ° F) or, when heated enough, lights up at 590 ° C (1,000 ° F). Even before the flame arrives at a particular location, heat transfer from the bonfire warms the air to 800 ° C (1,470 ° F), which heats and dries combustible materials, causing materials to burn faster and allowing fire to spread faster. Coffers of high-temperature and long-lasting surface fires may induce flashover or burning: the canopy drift of trees and subsequent ignition from below.
Wildfires have a fast forwarding rate (FROS) when burned through solid and uninterrupted fuels. They can move as fast as 10.8 kilometers per hour (6.7 mph) in the forest and 22 kilometers per hour (14 mph) in the pasture. Wildfires can advance the main front tangential to form the front flank, or incinerate in the opposite direction from the main front with backing . They can also spread by jumping or spotting when the wind and vertical convection columns bring firebrands (hot wood coals) and other fuels over the air above roads, rivers, and other obstacles that may act as firebreaks. Torching and fires in the canopy of trees encourage spotting, and the dry ground fuels that surround the fire are particularly susceptible to ignition from the torch. Spotting can make fire spots as hot fires and ignition winds ignite the fuel against the wind direction from the fire. In Australian forest fires, fire points are known to occur as far as 20 kilometers (12 miles) from the front of the fire.
Very large forest fires can affect airflow in the immediate vicinity with the spillage effect: the air rises when heated, and large forest fires create a strong airflow that will attract fresh, colder air from the surrounding area in the hot column. The big difference in temperature and humidity pushes pyrocumulus clouds, strong winds, and fire spins with tornado power at speeds of over 80 kilometers per hour (50 mph). Fast dispersal rates, productive projections or spots, the presence of spinning fires, and strong convection columns indicate extreme conditions.
Thermal heat from the fire can cause significant weathering of rocks and stones, heat can rapidly expand the chunk of rock and thermal shock may occur, which may cause the structure of the object to fail.
Weather effects
Heat waves, droughts, climate change cycles such as El Nià ± o, and regional weather patterns such as high-pressure mountains can increase the risk and dramatically change the behavior of forest fires. Years of rain followed by a warm period may encourage wider fires and longer fires. Since the mid-1980s, the beginning of snow melting and associated warming has also been attributed to an increase in the length and severity of the fire season in the Western United States. Global warming can increase the intensity and frequency of drought in many areas, creating more intense and frequent forest fires. A 2015 study indicates that increased fire risk in California may be caused by human-induced climate change. A study of alluvial sediment deposits that returned over 8,000 years found warmer climatic periods experiencing severe drought and fires that replaced positions and concluded that climate is very influential on forest fires attempting to re-create preschool forest structures is unlikely in the future. warmer.
Intensity also increases during the daytime hours. The rate of burning fires burns up to five times larger during the day due to lower humidity, increased temperature, and increased wind speed. Sunlight warms the soil during the day that creates a rising airflow. At night, the land cools, creating a descending air current. Wildfires fan by this wind and often follow the air currents over the hills and through the valleys. Fires in Europe often occur during 12:00 noon. and 2:00 pm The fire suppression operation in the United States revolves around 24 hours of fire day beginning at 10:00 am due to an increase in predictable intensity resulting from daytime warmth.
Ecology
Wildfire incidents throughout the history of terrestrial life invite allegations that fire must have had an evolutionary impact on most ecosystem flora and fauna. Forest fires often occur in humid enough climates to allow for the growth of vegetation but have extended periods of dryness and heat. Places like that include the vegetation areas of Australia and Southeast Asia, the tree in southern Africa, fynbos in the Cape West of South Africa, the forests of the United States and Canada, and the Mediterranean Basin.
High-sized forest fires create a complex early forest habitat habitat (also called "swamp forest habitat"), which often has a wealth and diversity of species higher than unburned old forests. Plant and animal species in most forests in North America evolve with fire, and many of these species depend on wildfires, and especially high-severity fires, to breed and grow. Fire helps to restore nutrients from plant matter back to the ground, heat from fire is required for the germination of certain types of seeds, and obstacles (dead trees) and early successional forests created by high severity fires create favorable habitat conditions for wildlife. Early successional forests created by high-level fires support some of the highest levels of native biodiversity found in temperate conifer forests. Post-fire logging has no ecological benefits and many negative impacts; the same thing often happens in post-fire seedlings.
Although some ecosystems depend on naturally occurring fires to regulate growth, some ecosystems suffer from too many fires, such as Kaparal in southern California and the lowland desert in Southwest America. Increased fire frequency in these fire-dependent areas has disrupted the natural cycle, damaged indigenous plant communities, and encouraged the growth of non-native weeds. Invasive species, such as Lygodium microphyllum and Bromus tectorum, can grow rapidly in areas damaged by fire. Because they are highly flammable, they can increase the risk of fire in the future, creating a positive feedback loop that increases the frequency of fires and further transforms the original vegetation community.
In the Amazon Rainforest, drought, logging, livestock practices, and slash-and-burn farming undermine fireproof forests and encourage the growth of flammable brushes, creating cycles that encourage more combustion. Rainforest fires threaten the collection of diverse species and produce substantial CO 2 . Also, fires in the rainforest, along with drought and human involvement, can damage or destroy more than half of the Amazon rainforest by 2030. Forest fires produce ash, reduce the availability of organic nutrients, and cause increased water runoff, erode far more nutrients and create banjir bandang condition. The 2003 fire in North Yorkshire Moors burned 2.5 square kilometers (600 hectares) of heather and the underlying peat layer. After that, wind erosion disarms the ash and open ground, revealing archaeological remains dating from 10,000 BC. Forest fires can also impact climate change, increase the amount of carbon released into the atmosphere and inhibit vegetation growth, which affects overall carbon uptake by plants.
In the tundra there is a natural pattern of fuel accumulation and fire that varies depending on the nature of vegetation and terrain. Research in Alaska has demonstrated the fire recurrence interval, (FRI) which typically varies from 150 to 200 years with the more often burning lowland areas compared to the wetland highlands.
Cropping adaptation
Plants in fire prone ecosystems often survive through adaptation to their local fire regime. Such adaptations include physical protection against heat, increased growth after a fire event, and combustible materials that fuel fires and can eliminate competition. For example, plants of the genus Eucalyptus contain flammable oils that propel fires and hard sclerofil leaves to withstand heat and drought, ensuring their dominance over species that are less tolerant of fire. Dense bark, lower branches, and high water content in external structures can also protect trees from rising temperatures. Fire-resistant seedlings and bamboo shoots that grow after fires encourage species preservation, as embodied by pioneer species. Smoke, charred wood, and heat can stimulate seed germination in a process called serotiny . Exposure to smoke from burning crops encourages germination in other plant species by encouraging the production of citrus butenolide.
Grasslands in Sabah Barat, Malaysian pine forests, and Indonesia's forests The atmospheric effect
Much of the Earth's weather and air pollution is in the troposphere, the atmospheric part extending from the planet's surface to a height of about 10 kilometers (6 mi). Vertical lifts from severe lightning storms or pyrocumulonimbus can be increased in large fire areas, which can drive smoke, soot, and other particulate matter as high as the lower stratosphere. Previously, the prevailing scientific theory states that most of the particles in the stratosphere are from volcanoes, but smoke and other fire emissions have been detected from the lower stratosphere. Pyrocumulus clouds can reach 6,100 meters (20,000 feet) above forest fires. Satellite observations from smoke clumps from forest fires reveal that clumps can be traced intact for distances beyond 1,600 kilometers (1,000 mi). Computer aided models like CALPUFF can help predict the size and direction of smoke blobs produced by fires by using atmospheric dispersion modeling.
Wildfires can affect local atmospheric pollution, and release carbon in the form of carbon dioxide. Fire emissions contain fine particles that can cause cardiovascular and respiratory problems. Increased byproducts of flame in the troposphere can increase ozone concentrations beyond safe levels. Forest fires in Indonesia in 1997 are estimated to have released between 0.81 and 2.57 gigatonnes (0.89 and 2.83 billion shorts) of CO 2 to the atmosphere, ie between 13% -40% of the annual global emissions of carbon dioxide from burning fossil fuels. The atmospheric model shows that the concentration of soot particles can increase the absorption of incoming solar radiation during winter by as much as 15%.
History
In Welsh Borders, the first evidence of forest fires is a fossilized rhyniophytoid plant preserved as charcoal, dating from the Silur period (approximately 420 million years ago ). Fierce surface fire began shortly before the Early Devonian period 405 million years ago . Low atmospheric oxygen during Central and Late Devonian is accompanied by a decrease in abundance of charcoal. Additional charcoal evidence indicates that fires continued throughout the Carbon period. Then, the overall increase of atmospheric oxygen from 13% in the Devonian End to 30-31% by the Final Permian is accompanied by wider spread of forest fires. Subsequently, the decrease in charcoal deposits associated with wild flames from the late Permian to Triassic period is explained by the decrease in oxygen levels.
Forest fires during the Paleozoic and Mesozoic periods follow a pattern similar to fires occurring in modern times. The surface fire that is driven by the dry season is clearly visible in the forests of the Devonian and Carbon progymnosperms. Carboniferous-era lepidodendron forest has a charred peak, evidence of a crown fire. In jurassic gymnosperm jungle, there is evidence of high frequency, light surface fires. An increase in fire activity at the end of Tertiary may be due to an increase in C 4 grass-type grass. As these grasses shift to more mesmeric habitats, their high flammability increases the frequency of fires, promoting pasture over the forest. However, fire-prone habitats may have contributed to the superiority of trees such as the genus Eucalyptus , Pines and Sequoia , which have thick bark to withstand fires and using serotiny.
Human involvement
The use of fire by humans for agricultural purposes and hunting during the Paleolithic and Mesolithic times changed the landscape and pre-existing fire regimes. Woodlands are gradually being replaced by smaller vegetation that facilitates travel, hunting, seed collection and planting. In human history records, a small allusion to forest fires is mentioned in the Bible and by classical authors such as Homer. However, while the ancient Hebrew, Greek and Roman writers were aware of the fires, they were not particularly interested in the untested lands where forest fires occurred. Forest fires are used in combat throughout human history as early thermal weapons. From medieval times, reports were written about burning jobs as well as customs and laws governing the use of fire. In Germany, the usual burning was documented in 1290 at Odenwald and in 1344 in the Black Forest. In the 14th century Sardinia, fuelbreaks were used for forest fire protection. In Spain during the 1550s, sheep farming was prevented in certain provinces by Philip II because of the harmful effects of fires used in transhumance. At the beginning of the 17th century, Native Americans were observed using fire for many purposes including planting, signaling, and warfare. Scottish botanist David Douglas notes the original use of fire for tobacco cultivation, to propel deer into smaller areas for hunting purposes, and to improve foraging for honey and locusts. The charcoal found in sediment deposits off the Pacific coast of Central America shows that more burning occurred within 50 years before Spanish colonization in America than after colonization. In the post-World War II Baltic region, socio-economic changes led to more stringent air quality standards and a ban on fires that eliminated traditional burning practices. In the mid-19th century, explorers from HMS
Forest fires usually occur during periods of rising temperatures and droughts. The increase in the flow of fire-related debris in alluvial fans from Yellowstone National Park northeast is associated with periods between 1050 and 1200, coinciding with the Medieval Warm Period. However, human influence causes an increase in fire frequency. Data on dendrochronological fires and charcoal data in Finland show that, while many fires occur during severe drought conditions, an increase in the number of fires during 850 BC and 1660 AD can be attributed to human influences. American charcoal evidence suggests a general reduction of forest fires between 1M and 1750 compared with previous years. However, the period of increasing fire frequencies between 1750 and 1870 is suggested by the data of charcoal from North America and Asia, attributed to the growth of human populations and effects such as land-clearing practices. This period was followed by a decline in overall combustion in the 20th century, related to agricultural expansion, increased livestock grazing, and fire prevention efforts. A meta-analysis found that 17 times more land burns annually in California before 1800 compared to the last decade (1,800,000 hectares/year compared to 102,000 hectares/year).
According to a paper published in Science, the number of natural and human-caused fires decreased by 24.3% between 1998 and 2015. The researchers explain this transition from nomadism to sedentary lifestyles and agricultural intensification leading to a decline in fire use. for land clearing.
Human-driven invasive species in some cases increase the intensity of forest fires, such as Eucalyptus in California and gamba grasses in Australia.
Prevention
Fire prevention refers to a preemptive method that aims to reduce the risk of fire and reduce its severity and spread. Preventive techniques aim to manage air quality, maintain ecological balance, protect resources, and influence future fires. North American fire policy naturally allows fires to burn to maintain their ecological role, as long as the risk of escape to high value areas is reduced. However, prevention policies should take into consideration the role that humans play in forest fires, because, for example, 95% of forest fires in Europe are linked to human involvement. Human-caused sources of fire may include combustion, accidental ignition, or uncontrolled use of fire in land clearing and agriculture such as slash-and-burn agriculture in Southeast Asia.
In 1937, US President Franklin D. Roosevelt embarked on a national fire prevention campaign, highlighting the role of human carelessness in forest fires. Then the poster of the program features Uncle Sam, a character from the Disney movie Bambi , and the official mascot of the US Forest Service, Smokey Bear. Reducing human-induced ignition may be the most effective way to reduce unwanted wildfire. Fuel changes are generally made when trying to influence future risk and fire behavior. Worldwide forest fire prevention programs can use techniques such as wild forest fire use and defined or controlled burns . The use of campfire refers to the natural cause of fire that is monitored but left to burn. Controlled burns are fires lit by government agencies under less hazardous weather conditions.
Vegetation can be burned at regular intervals to maintain a high species diversity and often burn surface fuel to limit fuel accumulation. The use of fire in the wilderness is the cheapest and most ecologically appropriate policy for many forests. Fuel can also be removed by felling, but fuel maintenance and thinning have no effect on severe fire behavior. The Wildfire model is often used to predict and compare the benefits of different fuel treatments on future fire spreads, but the accuracy is low.
Wildfire itself reportedly "the most effective treatment to reduce the rate of fire spread, the intensity of the fire line, the length of fire, and heat per unit area" according to Jan van Wagtendonk, a biologist at Yellowstone Field Station.
Building codes in fire prone areas usually require that structures constructed from refractory materials and maintained space are maintained by cleaning up combustible materials within the specified range of structures. Communities in the Philippines also maintain a 5 to 10 meter (16 to 33 feet) line of fire between their forest and village, and patrol these lines during the summer months or dry weather seasons. The continued development of housing in fire prone areas and the rebuilding of structures destroyed by fires has been met with criticism. The ecological benefits of fire are often overridden by the economic and safety benefits of protecting human structures and lives.
Detect
Rapid and effective detection is a key factor in fire fighting. Early detection efforts are focused on early response, accurate results both day and night, and the ability to prioritize fire hazards. The fire monitoring tower was used in the United States in the early 20th century and fires were reported using telephone, postal pigeons, and heliographs. Aerial and terrestrial photography using instant cameras was used in the 1950s until infrared scanning was developed for fire detection in the 1960s. However, the analysis and delivery of information is often delayed due to limitations in communication technology. Initial fire-derived fire analysis was hand drawn on maps in remote locations and sent by mail last night to fire managers. During the Yellowstone fire of 1988, a data station was established in West Yellowstone, enabling the transmission of satellite based fire information within about four hours.
Currently, public hotlines, fire monitors in towers, and land and air patrols can be used as a means of early detection of forest fires. However, accurate human observation may be limited by operator fatigue, time, time of year, and geographic location. Electronic systems have gained popularity in recent years as a possible resolution for human operator error. A government report on the latest trials of three automatic camera detection systems in Australia, however, concluded "... detection by the camera system is slower and less reliable than by trained human observers". These systems may be semi or fully automated and use systems based on risk areas and human presence levels, as suggested by GIS data analysis. An integrated approach of multiple systems can be used to combine satellite data, aerial imagery, and personnel positions through a Global Positioning System (GPS) into a collective whole for almost instantaneous use by Wireless Incident Command Centers.
Small, high-risk areas with thick vegetation, strong human presence, or close to critical urban areas can be monitored using a local sensor network. The detection system may include wireless sensor networks that act as automatic weather systems: detecting temperature, humidity, and smoke. It may be battery-powered, solar-powered, or tree refill : it can recharge their battery system using a small electrical current in plant material. Larger intermediate-risk areas can be monitored by scanning towers that combine cameras and fixed sensors to detect smoke or additional factors such as the infrared sign of carbon dioxide generated by fires. Additional capabilities such as night vision, brightness detection, and color change detection can also be incorporated into the sensor array.
Satellite and air monitoring through the use of aircraft, helicopters, or UAVs can provide a broader view and may be sufficient to monitor very large low-risk areas. These more sophisticated systems use high-resolution, high-resolution GPS and infrared cameras to identify and target forest fires. Satellite-mounted sensor such as Envisat Advanced Along Track Scanning Radiometer and European Remote-Sensing Satellite's Track Scanning Radiometer can measure infrared radiation emitted by fire, identify hot spots over 39 ° C (102 ° F). The National Oceanic and Atmospheric Hazard Mapping System combines remote sensing data from satellite sources such as Geostationary Operational Environmental Satellites (GOES), Medium-Resolution Imaging Spectroradiometer (MODIS), and High Resolution Radiometer (AVHRR) to detect fire and smoke smoke locations. However, satellite detection is susceptible to offset errors, anywhere from 2 to 3 kilometers (1 to 2 mi) for MODIS and AVHRR data and up to 12 kilometers (7.5 million) for GOES data. Satellites in geostationary orbit can become defective, and satellites in polar orbits are often limited by their short observation time windows. Cloud cover and image resolution and may also limit the effectiveness of satellite imagery.
by 2015 a new fire detector operates in the US Department of Agriculture's (USFS) Forest Service (USFS) using data from the Suomi National Polar-Orbiting Partnership (NPP) satellite to detect smaller fires in more detail than previous space-based products. High resolution data are used with computer models to predict how fires will change direction based on weather and soil conditions. Active fire detection products using data from Suomi NPP's Visible Infrared Imaging Radiometer Suite (VIIRS) increased the resolution of fire observations to 1,230 feet (375 meters). The NASA satellite data products previously available since the early 2000s were observed to fire at 3,280 feet (1 kilometer) resolution. The data is one of the intelligence tools used by the USFS and Ministry of Home Affairs agencies throughout the United States to guide resource allocation and strategic fire management decisions. Improved VIIRS fire products allow detection every 12 hours or less from much smaller fires and provide more detail and consistent fire line tracking during long-term forest fires - an important ability for early warning systems and routine fire mapping support. The fire's active location is available to users within minutes of the satellite bridge through data processing facilities at the USFS Remote Sensing Application Center, which uses technology developed by NASA's Goddard Space Flight Center Direct Readout Laboratory in Greenbelt, Maryland. This model uses data on weather conditions and ground around the active fire to predict the previous 12-18 hours if the fire will shift direction. The state of Colorado decided to combine weather-fire models in its fire fighting efforts beginning with the 2016 fire season.
In 2014, international campaigns are held in South Africa's Kruger National Park to validate fire detection products including the new VIIRS active fire data. Prior to the campaign, the Meraka Institute of the Scientific and Industrial Research Council in Pretoria, South Africa, the early adopter of the VIIRS 375m fire product, used it during several major forest fires in Kruger.
The demand for timely and high quality fire information has increased in recent years. Forest fires in the United States burn an average of 7 million hectares of land each year. Over the past 10 years, the USFS and the Ministry of Internal Affairs have spent a combined average of about $ 2-4 billion per year for forest fire suppression.
Oppression
The fire suppression depends on the technology available in the area where the fire occurred. In less developed countries the techniques used can be as simple as throwing sand or beating a fire with a stick or a palm leaf. In more advanced countries, the emphasis method varies due to technological capacity improvements. Silver iodide can be used to encourage snow fall, while flame and water retardants can fall into flames by unmanned aerial vehicles, aircraft, and helicopters. Complete fire suppression is no longer a hope, but the majority of forest fires are often extinguished before they grow out of control. While more than 99% of the 10,000 new forest fires each year are contained, forest fires that escape under extreme weather conditions are difficult to suppress without climate change. Forest fires in Canada and the US burned an average of 54,500 square kilometers (13,000,000 hectares) per year.
Above all, forest fire battles can be deadly. The fire that burns the front can also change the direction unexpectedly and jump across the fire break. Heat and strong smoke can cause disorientation and loss of appreciation of the direction of fire, which can make fire very dangerous. For example, during the Mann Gulch fire in 1949 in Montana, USA, thirteen people who smoked died when they lost their communication ties, lost their way, and were followed by fire. In the February 2009 Australian forest fire, at least 173 people died and more than 2,029 homes and 3,500 buildings were lost when they were hit by fire.
The cost of wild fire suppression
In California, the US Forest Service spent about $ 200 million a year to suppress 98% of forest fires and up to $ 1 billion to suppress 2% of other fires that escaped early attacks and became large.
Wildfire security in Wildland
Firefighters on land face several life-threatening hazards including heat stress, fatigue, smoke and dust, as well as the risk of other injuries such as burns, cuts and scrapes, animal bites, and even rhabdomyolysis.
Particularly in hot weather conditions, fires present a risk of heat stress, which can lead to feelings of heat, fatigue, weakness, vertigo, headache, or nausea. Heat stress can develop into a heat strain, which requires physiological changes such as increased heart rate and core body temperature. It can cause heat-related illnesses, such as heat rash, cramps, fatigue or heat stroke. Various factors can contribute to the risks posed by heat stress, including heavy work, personal risk factors such as age and fitness, dehydration, sleep deprivation, and incriminating personal protective equipment. Rest, cold water, and occasional breaks are essential to reduce the impact of heat stress.
Smoke, ash, and debris can also pose a serious respiratory danger to wilderness fire fighters. Smoke and dust from forest fires can contain gases such as carbon monoxide, sulfur dioxide and formaldehyde, as well as particles such as ash and silica. To reduce smoke exposure, a forest fire predator crew must, whenever possible, rotate firefighters through thick smoke areas, avoid wind attacks against the wind, use equipment rather than people in the area of ​​detention, and minimize clean sweeps. Camps and command posts should also be located against the wind of fire. Clothing and protective equipment can also help minimize exposure to smoke and ash.
Firefighters are also at risk of heart attacks including strokes and heart attacks. Firefighters must maintain good physical fitness. Fitness programs, medical examinations and examination programs that include stress tests can minimize the risk of heart fire-fighting problems. Other injury hazards faced by forest fire fighters include slippage, travel and fall, burns, scratches and injuries from equipment and equipment, attacked by trees, vehicles or other objects, plant dangers such as thorns and poison ivy, snake and animal bites , vehicle crashes, electricity from power lines or lightning storms, and unstable building structures.
Flame retard
Fire retardants are used to slow down forest fires by inhibiting burning. They are a solution of ammonium phosphate and ammonium sulphate, as well as thickening agents. The decision to apply retardant depends on the magnitude, location and intensity of the fire. In certain cases, fire retardants may also be applied as preventive fire prevention measures.
A typical flame retainer contains the same agent as the fertilizer. Flame retention may also affect water quality through leaching, eutrophication, or abuse. The fireproof effects on drinking water remain unconvincing. Dilution factors, including the size of water bodies, rainfall, and water flow rates reduce the concentration and potential of fire retardants. Wild debris (ash and sediment) clogs rivers and reservoirs increases the risk of flooding and erosion that ultimately slows and/or destroys water treatment systems. There are still concerns about the fireproof effects on land, water, wildlife habitats, and watershed quality, additional research is needed. However, on the positive side, flame resistance (especially nitrogen and phosphorus components) has been shown to have a fertilizing effect on nutrient-deprived soils and thus creates a temporary increase in vegetation.
The current USDA procedure states that aerial flame retardation applications in the United States should clear a waterway at least 300 feet to protect the effects of runoff inhibitors. Use of fireproof air is necessary to avoid applications near waterways and endangered species (plant and animal habitats). Following the incidents of the application of fire-resistant abuse, the US Forest Service requests reporting and impact assessment to determine the mitigation, remediation, and/or limitation of future retardant use in the area.
Modeling
Fire modeling is concerned with the simulation of fire fiat numerals to understand and predict fire behavior. Fire modeling aims to assist fire suppression, improve the safety of firefighters and communities, and minimize damage. Using computational science, forest fire modeling involves statistical analysis of past fire events to predict the risk of spotting and front behavior. Various models of wildfire propagation have been proposed in the past, including simple ellipses and models of eggs and fan shaped. Early attempts to determine wild fire behavior assumed terrain and uniformity of vegetation. However, the proper behavior of the front flame is dependent on a variety of factors, including wind speed and steepness of the slopes. Modern growth models utilize a combination of past ellipsoidal descriptions and the Huygens Principle to simulate the growth of fire as a growing polygon. Extreme value theory can also be used to predict the size of large forest fires. However, large fires in excess of pressing ability are often considered statistical evils in standard analysis, although fire policies are more affected by large forest fires than small fires.
Risk and human exposure
The risk of forest fires is the chance that fires will start in or reach a certain area and potentially lose human value if that happens. Risk depends on variable factors such as human activity, weather patterns, availability of fire fuel, and the availability or lack of resources to suppress fires. Forest fires continue to pose a threat to the human population. However, geographic changes and human-caused climate change more frequently expose residents to forest fires and increase the risk of forest fires. It is estimated that the increase in forest fires arose from a century of fire suppression coupled with the rapid expansion of human development into fire prone areas. Wildfires are a natural occurrence that helps in promoting forest health. Global warming and climate change lead to rising temperatures and more drought across the country that contribute to an increased risk of forest fires.
Air hazard
The most noticeable detrimental effect of forest fires is the destruction of property. However, the release of harmful chemicals from the burning of wild land fuels also significantly impacts human health.
Fire smoke consists mainly of carbon dioxide and water vapor. Other common smoke components present in low concentrations are carbon monoxide, formaldehyde, acrolein, polyaromatic hydrocarbons, and benzene. Small particles suspended in air that come in solid form or in liquid droplets are also present in the smoke. 80-90% of wild smoke, with mass, is in a fine particle size class with a diameter of 2.5 micrometers or smaller.
Although high concentrations of carbon dioxide are in the smoke, it poses a low health risk due to low toxicity. In contrast, carbon monoxide and fine particles, especially 2.5 Ã,Âμm in diameter and smaller, have been identified as major health threats. Other chemicals are considered significant hazards but are found in concentrations that are too low to cause detectable health effects.
The level of exposure to a fire fumes against a person depends on the length, severity, duration, and distance of fire. People are exposed directly to the smoke through the respiratory tract despite inhaling air pollutants. Indirectly, people are exposed to fire debris that can contaminate soil and water supplies.
The US Environmental Protection Agency (EPA) developed the Air Quality Index (AQI), a public resource that provides a concentration of national air quality standards for common air pollutants. Communities can use this index as a tool to determine their exposure to harmful air pollutants based on visibility.
Group at risk
Firefighters are at greatest risk for acute and chronic health effects due to exposure to fire fumes. Due to the work of firefighters, they are often exposed to hazardous chemicals at close proximity for longer periods. A case study of exposure to smoke among firefighters indicates that firefighters are exposed to significant levels of carbon monoxide and respiratory irritation above the exposure limits allowed by OSHA (PEL) and ACGIH (TLV) threshold values. 5-10% is too bright. This study received concentration of exposure for one firefighter in peatland for more than 10 hours spent to hold a single firefighter. Firefighters are exposed to various kinds of carbon monoxide and respiratory irritation (combinations of particle levels of 3.5 Âμm and smaller, acrolein, and formaldehype). The carbon monoxide level reaches up to 160ppm and the TLV irritation index value is high 10. In contrast, OSHA PEL for carbon monoxide is 30ppm and for TLV respiratory irritation index, the calculated threshold value is 1; any value above 1 exceeds the exposure limits.
Between 2001 and 2012, more than 200 casualties occurred among the firefighters. In addition to the dangers of heat and chemicals, firefighters are also at risk of electric shock from power lines; injury from equipment; slip, travel, and fall; injury from vehicle rollover; heat-related diseases; insect bites and stings; emphasize; and rhabdomyolysis.
Residents in the vicinity of forest fires are exposed to lower concentrations of chemicals, but they are at a greater risk for indirect exposure through water or soil contamination. Exposure to the population depends heavily on the vulnerability of the individual. Vulnerable people such as children (ages 0-4), older people (age 65 and older), smokers, and pregnant women have an increased risk due to their compromised body systems, even when exposures are present at chemical concentrations low and for a relatively short period of exposure.
In addition, there is evidence of increased material stress, as documented by M.H. researchers. O'Donnell and A.M. Behie, thus affecting birth outcomes. In Australia, studies show that male babies born with higher birth weights are born higher in the most affected areas of the fire. This is attributed to the fact that the mother's signal directly affects the fetal growth pattern.
Health effects
Inhaling smoke from wild flames can be harmful to health. Fire smoke consists of carbon dioxide, water vapor, particles, organic chemicals, nitrogen oxides and other compounds. The main health problem is inhaling particles and carbon monoxide.
Particulate material (PM) is a type of air pollution consisting of dust particles and liquid droplets. They are characterized into two categories based on particle diameter. The coarse particles are between 2.5 micrometers and 10 micrometers and fine particles of 2.5 micrometers and less. Both sizes can be inhaled. The coarse particles are filtered by the upper airways and can cause irritation of the eyes and sinuses and sore throats and coughs. Fine particles are more problematic because when inhaled they can be stored deep into the lungs, where they are absorbed into the bloodstream. It is very dangerous for very young, elderly and those who have chronic conditions such as asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis and cardiovascular conditions. The most frequent diseases with exposure to fine particles from fire smoke are bronchitis, exacerbation of asthma or COPD, and pneumonia. Symptoms of this complication include wheezing and shortness of breath and cardiovascular symptoms including chest pain, rapid heartbeat and fatigue.
Carbon monoxide (CO) is a colorless and odorless gas that can be found at the highest concentrations near blazing fires. For this reason, carbon monoxide inhalation poses a serious threat to the health of firefighters. CO in the smoke can be inhaled to the lungs where it is absorbed into the bloodstream and reduces the delivery of oxygen to the body's vital organs. At high concentrations, it can cause headaches, weakness, dizziness, confusion, nausea, disorientation, visual impairment, coma and even death. However, even at lower concentrations, such as those found in forest fires, individuals with cardiovascular disease may experience chest pain and cardiac arrhythmias. A recent study that tracked the number and causes of death from firefighters from 1990-2006 found that 21.9% of deaths were due to a heart attack.
Another important and somewhat less obvious health effect of forest fires is psychiatric illness and disorders. Both adults and children from countries ranging from the United States and Canada to Greece and Australia are directly and indirectly affected by wildfires discovered by researchers to point out several different mental conditions related to their experience with forest fires. These include post-traumatic stress disorder (PTSD), depression, anxiety, and phobia.
In a new twist to the effects of fire health, the former uranium mining site was set on fire in the summer of 2012 near North Fork, Idaho. This sparked concerns from local residents and officials of the Department of Environmental Quality of the Department of Idaho regarding the potential for radiation spreading in the resulting smoke, since these sites were never completely cleared of radioactive remnants.
Epidemiology
EPA has established an acceptable particle concentration in air, through the Ambient National Air Quality Standard and ambient air quality monitoring has been mandated. Because of this monitoring program and the incidence of several large forest fires near populated areas, epidemiological studies have been conducted and show a link between human health effects and fine particle enhancement due to fire fumes.
The increase in PM emitted from the Hayman fires in Colorado in June 2002, was associated with increased respiratory symptoms in patients with COPD. Looking at forest fires in Southern California in October 2003 in the same way, researchers have shown an increase in hospital admissions due to asthma during PM peak concentrations. Children who participated in the Children's Health Study were also found to have elevated eye and respiratory symptoms, drug use and doctor visits. Recently, it was shown that mothers who became pregnant during the fires gave birth to babies with an average birth weight slightly less than those who were not exposed to fire during birth. It is suggested that pregnant women are also at greater risk of adverse effects of fire. Around the world it is estimated that 339,000 people die from the smoke effects of fire every year.
See also
References
Bibliography
Source of the article : Wikipedia
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