The wildland–urban interface ( WUI ) is a zone of transition between wilderness (unoccupied land) and land developed by human activity – an area where a built environment meets or intermingles with a natural environment . Human settlements in the WUI are at a greater risk of catastrophic wildfire .
77-587: The Skirball Fire was a wildfire that burned in the Bel Air neighborhood of Los Angeles , California, United States, and one of multiple wildfires that broke out across Southern California in December 2017. The fire burned 422 acres (171 ha) of land on the slopes of the Sepulveda Pass on its east or Bel Air side, causing the closure of Interstate 405 (as well as the parallel Sepulveda Boulevard ),
154-570: A defensible space be maintained by clearing flammable materials within a prescribed distance from the structure. Communities in the Philippines also maintain fire lines 5 to 10 meters (16 to 33 ft) wide between the forest and their village, and patrol these lines during summer months or seasons of dry weather. Continued residential development in fire-prone areas and rebuilding structures destroyed by fires has been met with criticism. The ecological benefits of fire are often overridden by
231-469: A 15 mile radius. Additionally, Sensaio Tech , based in Brazil and Toronto, has released a sensor device that continuously monitors 14 different variables common in forests, ranging from soil temperature to salinity. This information is connected live back to clients through dashboard visualizations, while mobile notifications are provided regarding dangerous levels. Satellite and aerial monitoring through
308-470: A 24-hour fire day that begins at 10:00 a.m. due to the predictable increase in intensity resulting from the daytime warmth. Climate change promotes the type of weather that makes wildfires more likely. In some areas, an increase of wildfires has been attributed directly to climate change. Evidence from Earth's past also shows more fire in warmer periods. Climate change increases evapotranspiration . This can cause vegetation and soils to dry out. When
385-453: A community is a fire-adapted community . The U.S. Forest Service defines fire-adapted communities as "a knowledgeable and engaged community in which the awareness and actions of residents regarding infrastructure, buildings, landscaping, and the surrounding ecosystem lessens the need for extensive protection actions and enables the community to safely accept fire as a part of the surrounding landscape." Three groups are responsible for achieving
462-675: A degree of wildfire threat. These are ecological factors that define force, human factors that define ignition, and vulnerability factors that define damage. These factors are typically viewed in a geospatial relationship. The ecological factor category includes climate, seasonal weather patterns, geographical distributions of vegetation, historical spatial wildfire data, and geographic features. The ecological determines wildfire size and intensity. The human factor category includes arrangement and density of housing. Density correlates with wildfire risk for two reasons. First, people cause fires; from 2001 to 2011, people caused 85% of wildfires recorded by
539-566: A doubling in land area burned by wildfires compared to natural levels. Humans have impacted wildfire through climate change (e.g. more intense heat waves and droughts ), land-use change , and wildfire suppression . The carbon released from wildfires can add to carbon dioxide concentrations in the atmosphere and thus contribute to the greenhouse effect . This creates a climate change feedback . Naturally occurring wildfires can have beneficial effects on those ecosystems that have evolved with fire. In fact, many plant species depend on
616-610: A fire starts in an area with very dry vegetation, it can spread rapidly. Higher temperatures can also lengthen the fire season. This is the time of year in which severe wildfires are most likely, particularly in regions where snow is disappearing. Weather conditions are raising the risks of wildfires. But the total area burnt by wildfires has decreased. This is mostly because savanna has been converted to cropland , so there are fewer trees to burn. Climate variability including heat waves , droughts , and El Niño , and regional weather patterns, such as high-pressure ridges, can increase
693-559: A fire; lower vegetation has a lower risk. A quantitative risk assessment simulation combines wildfire threat categories. Areas at the highest risk are those where a moderate population overlaps or is adjacent to a wildland that can support a large and intense wildfire and is vulnerable with limited evacuation routes. The Calkin framework predicts a catastrophic wildfire in the Wildland–urban Interface (WUI), with three categories of factors. These factors allow for an assessment of
770-607: A limited window and thus MTT is only applicable to short-timescale simulations. Structure and vegetation flammability is reduced through community-focused risk management through reduction of community vulnerabilities. The degree of control of vulnerability to wildfires is measured with metrics for responsibilities and zones of defenses. The probability of catastrophic WUI wildfire is controlled by assignment of responsibility for three actionable WUI objectives: controlling potential wildfire intensity, reducing ignition sources, and reducing vulnerability. When these objectives are met, then
847-629: A major traffic artery in the city. The Skirball Cultural Center , Bel-Air Country Club , Getty Center , Santa Monica-Malibu Unified School District , and various private schools were closed as a result of the fire. Classes were cancelled at the University of California, Los Angeles (UCLA) and Santa Monica College , while Mount Saint Mary's University evacuated from its Brentwood campus to its downtown Los Angeles location. The fire destroyed six structures and damaged 12. On December 10, at about 1 p.m. PST, all evacuation orders and road closures for
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#1732787942943924-546: A new fire detection tool is in operation at the U.S. Department of Agriculture (USDA) Forest Service (USFS) which uses data from the Suomi National Polar-orbiting Partnership (NPP) satellite to detect smaller fires in more detail than previous space-based products. The high-resolution data is used with a computer model to predict how a fire will change direction based on weather and land conditions. In 2014, an international campaign
1001-415: A number expected to rise to 30,000 by 2050. The economic impact is also significant, with projected costs reaching $ 240 billion annually by 2050, surpassing other climate-related damages. Over the past century, wildfires have accounted for 20–25% of global carbon emissions, the remainder from human activities. Global carbon emissions from wildfires through August 2020 equaled the average annual emissions of
1078-545: A policy of allowing some wildfires to burn is the cheapest method and an ecologically appropriate policy for many forests, they tend not to take into account the economic value of resources that are consumed by the fire, especially merchantable timber. Some studies conclude that while fuels may also be removed by logging, such thinning treatments may not be effective at reducing fire severity under extreme weather conditions. Building codes in fire-prone areas typically require that structures be built of flame-resistant materials and
1155-503: A possible resolution to human operator error. These systems may be semi- or fully automated and employ systems based on the risk area and degree of human presence, as suggested by GIS data analyses. An integrated approach of multiple systems can be used to merge satellite data, aerial imagery, and personnel position via Global Positioning System (GPS) into a collective whole for near-realtime use by wireless Incident Command Centers . A small, high risk area that features thick vegetation,
1232-531: A rapid forward rate of spread (FROS) when burning through dense uninterrupted fuels. They can move as fast as 10.8 kilometres per hour (6.7 mph) in forests and 22 kilometres per hour (14 mph) in grasslands. Wildfires can advance tangential to the main front to form a flanking front, or burn in the opposite direction of the main front by backing . They may also spread by jumping or spotting as winds and vertical convection columns carry firebrands (hot wood embers) and other burning materials through
1309-695: A remote site and sent via overnight mail to the fire manager . During the Yellowstone fires of 1988 , a data station was established in West Yellowstone , permitting the delivery of satellite-based fire information in approximately four hours. Public hotlines, fire lookouts in towers, and ground and aerial patrols can be used as a means of early detection of forest fires. However, accurate human observation may be limited by operator fatigue , time of day, time of year, and geographic location. Electronic systems have gained popularity in recent years as
1386-569: A strong human presence, or is close to a critical urban area can be monitored using a local sensor network . Detection systems may include wireless sensor networks that act as automated weather systems: detecting temperature, humidity, and smoke. These may be battery-powered, solar-powered, or tree-rechargeable : able to recharge their battery systems using the small electrical currents in plant material. Larger, medium-risk areas can be monitored by scanning towers that incorporate fixed cameras and sensors to detect smoke or additional factors such as
1463-407: A two-dimensional surface. Minimum Travel Time (MTT) methods build on Huygens' principle to find a minimum time for fire to travel between two points. MTT assumes nearly-constant factors such as environmental factors for wind direction and fuel moisture. The MTT is advantageous over Huygens in scalability and algorithm speed. However, factors are dynamic and a constant representation comes at a cost of
1540-838: A variety of effects on plant life. Depending on the influences that are present, some plant traits like woodiness and height may increase while many other traits either show mixe responses or are not well studied. Additionally, disease vectors in isolated patches can undergo genetic differentiation, increasing their survivability as a whole. Increases in wildfire risk pose a threat to conservation in WUI growth regions. Ecological change driven by human influence and climate change has often resulted in more arid and fire-prone WUI. Factors include climate change driven vegetation growth and introduction of non-native plants, insects, and plant diseases. In North America, Chile, and Australia, unnaturally high fire frequencies due to exotic annual grasses have led to
1617-481: A way that defense zones are effective (note: fire-resistant is arbitrary and is not defined in hours of resistance for a given degree of heat; these guidelines are relaxed for non- evergreen trees which are less flammable; this guide is not intended to prevent combustion of individual structures in a wildfire—it is intended to prevent catastrophic wildfire in the WUI): There are three challenges. An example of
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#17327879429431694-428: A wildfire is calculated by a Home Ignition Zone (HIZ) metric. The HIZ includes at a minimum the space within a 200 foot (61 m) radius around a structure. The HIZ is a guideline for whoever is responsible for structure wildfire protection; landlords and tenants (homeowner if they are the same) are responsible for physically constructing and maintaining defense zones while local government defines land use boundaries in
1771-512: Is expected the WUI will continue to expand; an anticipated amenity-seeking migration of retiring baby-boomers to smaller communities with lower costs of living close to scenic and recreational natural resources will contribute to WUI growth. Climate change is also driving population shifts into the WUI as well as changes in wildlife composition. Housing growth in WUI regions can displace and fragment native vegetation. The introduction of non-native species by humans through landscaping can change
1848-405: Is governed in part by topography , as land shape determines factors such as available sunlight and water for plant growth. Overall, fire types can be generally characterized by their fuels as follows: Wildfires occur when all the necessary elements of a fire triangle come together in a susceptible area: an ignition source is brought into contact with a combustible material such as vegetation that
1925-417: Is measured with evacuation time through a proximity of habitable structures to roads, matching of administrators to responsibilities, land use, building standards, and landscaping types. Wildfire spread is commonly simulated with a Minimum Travel Time (MTT) algorithm. Prior to MTT algorithms, fire boundaries were modeled through an application of Huygens' principle ; boundaries are treated as wave fronts on
2002-728: Is no longer an expectation, but the majority of wildfires are often extinguished before they grow out of control. While more than 99% of the 10,000 new wildfires each year are contained, escaped wildfires under extreme weather conditions are difficult to suppress without a change in the weather. Wildfires in Canada and the US burn an average of 54,500 square kilometers (13,000,000 acres) per year. Above all, fighting wildfires can become deadly. A wildfire's burning front may also change direction unexpectedly and jump across fire breaks. Intense heat and smoke can lead to disorientation and loss of appreciation of
2079-473: Is prone 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 mi) for GOES data. Satellites in geostationary orbits may become disabled, and satellites in polar orbits are often limited by their short window of observation time. Cloud cover and image resolution may also limit the effectiveness of satellite imagery. Global Forest Watch provides detailed daily updates on fire alerts. In 2015
2156-662: Is subjected to enough heat and has an adequate supply of oxygen from the ambient air. A high moisture content usually prevents ignition and slows propagation, because higher temperatures are needed to evaporate any water in the material and heat the material to its fire point . Dense forests usually provide more shade, resulting in lower ambient temperatures and greater humidity , and are therefore less susceptible to wildfires. Less dense material such as grasses and leaves are easier to ignite because they contain less water than denser material such as branches and trunks. Plants continuously lose water by evapotranspiration , but water loss
2233-590: Is true for a range of environments in North America, the Mediterranean Basin, Chile, and South Africa. Possible reasons for a decrease include decreases in open space for ember transmission, fuel fragmentation due to urban development, and higher availability of fire-suppression resources. Areas with moderate population densities tend to exhibit higher wildfire risk than areas with low or high population densities. The vulnerability factor category
2310-416: Is usually balanced by water absorbed from the soil, humidity, or rain. When this balance is not maintained, often as a consequence of droughts , plants dry out and are therefore more flammable. A wildfire front is the portion sustaining continuous flaming combustion, where unburned material meets active flames, or the smoldering transition between unburned and burned material. As the front approaches,
2387-418: The 2019–20 Australian bushfire season "an independent study found online bots and trolls exaggerating the role of arson in the fires." In the 2023 Canadian wildfires false claims of arson gained traction on social media; however, arson is generally not a main cause of wildfires in Canada. In California, generally 6–10% of wildfires annually are arson. Coal seam fires burn in the thousands around
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2464-965: The Amazon rainforest . The fires in the latter were caused mainly by illegal logging . The smoke from the fires expanded on huge territory including major cities, dramatically reducing air quality. As of August 2020, the wildfires in that year were 13% worse than in 2019 due primarily to climate change , deforestation and agricultural burning. The Amazon rainforest 's existence is threatened by fires. Record-breaking wildfires in 2021 occurred in Turkey , Greece and Russia , thought to be linked to climate change. The carbon released from wildfires can add to greenhouse gas concentrations. Climate models do not yet fully reflect this feedback . Wildfires release large amounts of carbon dioxide, black and brown carbon particles, and ozone precursors such as volatile organic compounds and nitrogen oxides (NOx) into
2541-569: The European Union . In 2020, the carbon released by California's wildfires was significantly larger than the state's other carbon emissions. Forest fires in Indonesia in 1997 were estimated to have released between 0.81 and 2.57 giga tonnes (0.89 and 2.83 billion short tons ) of CO 2 into the atmosphere, which is between 13–40% of the annual global carbon dioxide emissions from burning fossil fuels. In June and July 2019, fires in
2618-480: The Fire Information for Resource Management System (FIRMS). Between 2022–2023, wildfires throughout North America prompted an uptake in the delivery and design of various technologies using artificial intelligence for early detection, prevention, and prediction of wildfires. Wildfire suppression depends on the technologies available in the area in which the wildfire occurs. In less developed nations
2695-528: The National Interagency Fire Center (NIFC). Second, housing intensifies wildfires because they contain flammable material and produce mobile embers, such as wood shakes. The relationship between population density and wildfire risk is non-linear. At low population densities, human ignitions are low. Ignitions increase with population density. However, there is a threshold of population density at which fire occurrence decreases. This
2772-504: The Paris climate agreement . Due to the complex oxidative chemistry occurring during the transport of wildfire smoke in the atmosphere, the toxicity of emissions was indicated to increase over time. Atmospheric models suggest that these concentrations of sooty particles could increase absorption of incoming solar radiation during winter months by as much as 15%. The Amazon is estimated to hold around 90 billion tons of carbon. As of 2019,
2849-578: The fire-adapted communities performance was demonstrated in November 2018 when the Camp Fire passed through the community of Concow in Butte County, California. The Concow community was a fire-adapted community. This late season fire provided a stress test of the fire-adapted communities theory. The Concow community was destroyed. The wildfire continued through the community without demonstrating
2926-429: The taiga biome are particularly susceptible. Wildfires can severely impact humans and their settlements. Effects include for example the direct health impacts of smoke and fire, as well as destruction of property (especially in wildland–urban interfaces ), and economic losses. There is also the potential for contamination of water and soil. At a global level, human practices have made the impacts of wildfire worse, with
3003-463: The Arctic emitted more than 140 megatons of carbon dioxide, according to an analysis by CAMS. To put that into perspective this amounts to the same amount of carbon emitted by 36 million cars in a year. The recent wildfires and their massive CO 2 emissions mean that it will be important to take them into consideration when implementing measures for reaching greenhouse gas reduction targets accorded with
3080-547: The Skirball Fire were lifted, as containment of the wildfire increased to 85%. Late on December 15, it was reported that the Skirball Fire had been 100% contained, at 422 acres (171 ha). On December 12, it was reported on that the fire had been sparked by an illegal cooking fire at a homeless encampment within the pass. During the Skirball Fire, firefighters in the LAFD employed drones to help them combat wildfires for
3157-505: The United States in the early 20th century and fires were reported using telephones, carrier pigeons , and heliographs . Aerial and land photography using instant cameras were used in the 1950s until infrared scanning was developed for fire detection in the 1960s. However, information analysis and delivery was often delayed by limitations in communication technology. Early satellite-derived fire analyses were hand-drawn on maps at
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3234-583: The United States, the wildland–urban interface (WUI) has two definitions. The US Forest Service defines the wildland–urban interface qualitatively as a place where "humans and their development meet or intermix with wildland fuel." Communities that are within 0.5 miles (0.80 km) of the zone are included. A quantitative definition is provided by the Federal Register , which defines WUI areas as those containing at least one housing unit per 40 acres (16 ha). The Federal Register definition splits
3311-444: The WUI into two categories based on vegetation density: Human development has increasingly encroached into the wildland–urban interface. The WUI was the fastest-growing land use type in the United States between 1990 and 2010. Factors include geographic population shifts, expansion of cities and suburbs into wildlands, and vegetative growth into formerly unvegetated land. The primary cause has been migration. Of new WUI areas, 97% were
3388-779: The Western US, earlier snowmelt and associated warming has also been associated with an increase in length and severity of the wildfire season, or the most fire-prone time of the year. A 2019 study indicates that the increase in fire risk in California may be partially attributable to human-induced climate change . In the summer of 1974–1975 (southern hemisphere), Australia suffered its worst recorded wildfire, when 15% of Australia's land mass suffered "extensive fire damage". Fires that summer burned up an estimated 117 million hectares (290 million acres ; 1,170,000 square kilometres ; 450,000 square miles ). In Australia,
3465-435: The air over roads, rivers, and other barriers that may otherwise act as firebreaks . Torching and fires in tree canopies encourage spotting, and dry ground fuels around a wildfire are especially vulnerable to ignition from firebrands. Spotting can create spot fires as hot embers and firebrands ignite fuels downwind from the fire. In Australian bushfires , spot fires are known to occur as far as 20 kilometres (12 mi) from
3542-732: The annual number of hot days (above 35 °C) and very hot days (above 40 °C) has increased significantly in many areas of the country since 1950. The country has always had bushfires but in 2019, the extent and ferocity of these fires increased dramatically. For the first time catastrophic bushfire conditions were declared for Greater Sydney. New South Wales and Queensland declared a state of emergency but fires were also burning in South Australia and Western Australia. In 2019, extreme heat and dryness caused massive wildfires in Siberia , Alaska , Canary Islands , Australia , and in
3619-444: The atmosphere. These emissions affect radiation, clouds, and climate on regional and even global scales. Wildfires also emit substantial amounts of semi-volatile organic species that can partition from the gas phase to form secondary organic aerosol (SOA) over hours to days after emission. In addition, the formation of the other pollutants as the air is transported can lead to harmful exposures for populations in regions far away from
3696-859: The bulk in modern history occurred after 2003. In the United States, from 1985 to 2016, federal wildfire suppression expenditures tripled from $ 0.4 billion per year to $ 1.4 billion per year. Evacuations in WUI regions could be complex due to densely populated communities, limited road networks, and varying levels of preparedness and risk perception among residents can lead to congestion, delays, and unsafe evacuation routes. The diverse demographics in these areas —ranging from elderly populations to young families— require tailored evacuation strategies to accommodate different vulnerabilities and safety needs. Effective WUI evacuation planning must balance early warning systems, clear communication, adequate infrastructure, and community engagement to enhance preparedness and ensure rapid, safe responses in emergencies. Calculating
3773-615: The direction of the fire, which can make fires particularly dangerous. For example, during the 1949 Mann Gulch fire in Montana , United States, thirteen smokejumpers died when they lost their communication links, became disoriented, and were overtaken by the fire. In the Australian February 2009 Victorian bushfires , at least 173 people died and over 2,029 homes and 3,500 structures were lost when they became engulfed by wildfire. Wildland%E2%80%93urban interface In
3850-697: The earth's atmosphere has 415 parts per million of carbon, and the destruction of the Amazon would add about 38 parts per million. Some research has shown wildfire smoke can have a cooling effect. Research in 2007 stated that black carbon in snow changed temperature three times more than atmospheric carbon dioxide. As much as 94 percent of Arctic warming may be caused by dark carbon on snow that initiates melting. The dark carbon comes from fossil fuels burning, wood and other biofuels, and forest fires. Melting can occur even at low concentrations of dark carbon (below five parts per billion)". Wildfire prevention refers to
3927-411: The economic and safety benefits of protecting structures and human life. The demand for timely, high-quality fire information has increased in recent years. Fast and effective detection is a key factor in wildfire fighting. Early detection efforts were focused on early response, accurate results in both daytime and nighttime, and the ability to prioritize fire danger. Fire lookout towers were used in
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#17327879429434004-552: The effect of weather on the fire. Wildfire severity results from a combination of factors such as available fuels, physical setting, and weather. Climatic cycles with wet periods that create substantial fuels, followed by drought and heat, often precede severe wildfires. These cycles have been intensified by climate change . Wildfires are a common type of disaster in some regions, including Siberia (Russia), California (United States), British Columbia (Canada), and Australia . Areas with Mediterranean climates or in
4081-412: The effects of fire for growth and reproduction. The ignition of a fire takes place through either natural causes or human activity (deliberate or not). Natural occurrences that can ignite wildfires without the involvement of humans include lightning , volcanic eruptions , sparks from rock falls, and spontaneous combustions . Sources of human-caused fire may include arson, accidental ignition, or
4158-436: The expected slowing of the flame front. If there was a slowing it was less than anticipated though any slowing contributed to allowing residents to evacuate ahead of the flame front. The wildfire continued through wildlands between the community of Concow and the town of Paradise, California. The wildfire then destroyed the town of Paradise which was in the process of developing into a fire-adapted community. The wildfire ignition
4235-402: The fire front. Especially large wildfires may affect air currents in their immediate vicinities by the stack effect : air rises as it is heated, and large wildfires create powerful updrafts that will draw in new, cooler air from surrounding areas in thermal columns . Great vertical differences in temperature and humidity encourage pyrocumulus clouds , strong winds, and fire whirls with
4312-417: The fire heats both the surrounding air and woody material through convection and thermal radiation . First, wood is dried as water is vaporized at a temperature of 100 °C (212 °F). Next, the pyrolysis of wood at 230 °C (450 °F) releases flammable gases. Finally, wood can smolder at 380 °C (720 °F) or, when heated sufficiently, ignite at 590 °C (1,000 °F). Even before
4389-566: The first time. This fire threatened the home of Frank Luntz , the Republican political consultant who had previously sought to downplay the severity of the climate change crisis. He later cited this experience as an "example of the climate crisis made personal," and shifted his viewpoint to advocate for climate action. Wildfire A wildfire , forest fire , or a bushfire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation . Depending on
4466-452: The flames of a wildfire arrive at a particular location, heat transfer from the wildfire front warms the air to 800 °C (1,470 °F), which pre-heats and dries flammable materials, causing materials to ignite faster and allowing the fire to spread faster. High-temperature and long-duration surface wildfires may encourage flashover or torching : the drying of tree canopies and their subsequent ignition from below. Wildfires have
4543-441: The force of tornadoes at speeds of more than 80 kilometres per hour (50 mph). Rapid rates of spread, prolific crowning or spotting, the presence of fire whirls, and strong convection columns signify extreme conditions. Intensity also increases during daytime hours. Burn rates of smoldering logs are up to five times greater during the day due to lower humidity, increased temperatures, and increased wind speeds. Sunlight warms
4620-454: The ground during the day which creates air currents that travel uphill. At night the land cools, creating air currents that travel downhill. Wildfires are fanned by these winds and often follow the air currents over hills and through valleys. Fires in Europe occur frequently during the hours of 12:00 p.m. and 2:00 p.m. Wildfire suppression operations in the United States revolve around
4697-495: The infrared signature of carbon dioxide produced by fires. Additional capabilities such as night vision , brightness detection, and color change detection may also be incorporated into sensor arrays . The Department of Natural Resources signed a contract with PanoAI for the installation of 360 degree 'rapid detection' cameras around the Pacific northwest, which are mounted on cell towers and are capable of 24/7 monitoring of
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#17327879429434774-471: The loss of native shrublands. Human development has increasingly encroached into the wildland–urban interface. Coupled with a recent increase in large wildland fires, this has led to an increase in fire protection costs. Between 1985–1894 and 2005–2014, the area burned by wildfires in the United States nearly doubled from 18,000 to 33,000 square kilometers. Wildfires in the United States exceeding 50,000 acres (20,000 ha) have steadily increased since 1983;
4851-484: The preemptive methods aimed at reducing the risk of fires as well as lessening its severity and spread. Prevention techniques aim to manage air quality, maintain ecological balances, protect resources, and to affect future fires. Prevention policies must consider the role that humans play in wildfires, since, for example, 95% of forest fires in Europe are related to human involvement. Wildfire prevention programs around
4928-592: The result of new housing. In the United States there are population shifts towards the WUIs in the West and South; increasing nationally by 18 percent per decade, covering 6 million additional homes between 1990 and 2000 which in 2013 was 32 percent of habitable structures. Globally, WUI growth includes regions such as Argentina, France, South Africa, Australia, and regions around the Mediterranean sea. Going forward it
5005-404: The risk and alter the behavior of wildfires dramatically. Years of high precipitation can produce rapid vegetation growth, which when followed by warmer periods can encourage more widespread fires and longer fire seasons. High temperatures dry out the fuel loads and make them more flammable, increasing tree mortality and posing significant risks to global forest health. Since the mid-1980s, in
5082-447: The risk posed to a structure located within a WUI is through predictive factors and simulations. Identifying risk factors and simulation with those factors help to understand and then manage the wildfire threat. For example, a proximity factor measures the risk of fire from wind carried embers which can ignite new spot fires over a mile ahead of a flame front. A vegetation factor measures the risk those wind carried embers have of starting
5159-399: The techniques used can be as simple as throwing sand or beating the fire with sticks or palm fronds. In more advanced nations, the suppression methods vary due to increased technological capacity. Silver iodide can be used to encourage snow fall, while fire retardants and water can be dropped onto fires by unmanned aerial vehicles , planes , and helicopters . Complete fire suppression
5236-416: The three WUI objectives, these are land management agencies, local governments, and individuals. Fire-adapted communities have been successful in interacting with wildfires. The key benefit of fire-adapted communities is that a reliance on individuals as a core block in the responsibility framework reduces WUI expenditures by local, regional, and national governments. The risk of a structure to ignite in
5313-723: The type of vegetation present, a wildfire may be more specifically identified as a bushfire ( in Australia ), desert fire, grass fire, hill fire, peat fire, prairie fire, vegetation fire, or veld fire. Some natural forest ecosystems depend on wildfire. Wildfires are different from controlled or prescribed burning , which are carried out to provide a benefit for people. Modern forest management often engages in prescribed burns to mitigate fire risk and promote natural forest cycles. However, controlled burns can turn into wildfires by mistake. Wildfires can be classified by cause of ignition, physical properties, combustible material present, and
5390-540: The uncontrolled use of fire in land-clearing and agriculture such as the slash-and-burn farming in Southeast Asia. In the tropics , farmers often practice the slash-and-burn method of clearing fields during the dry season . In middle latitudes , the most common human causes of wildfires are equipment generating sparks (chainsaws, grinders, mowers, etc.), overhead power lines , and arson . Arson may account for over 20% of human caused fires. However, in
5467-936: The use of planes, helicopter, or UAVs can provide a wider view and may be sufficient to monitor very large, low risk areas. These more sophisticated systems employ GPS and aircraft-mounted infrared or high-resolution visible cameras to identify and target wildfires. Satellite-mounted sensors such as Envisat 's Advanced Along Track Scanning Radiometer and European Remote-Sensing Satellite 's Along-Track Scanning Radiometer can measure infrared radiation emitted by fires, identifying hot spots greater than 39 °C (102 °F). The National Oceanic and Atmospheric Administration 's Hazard Mapping System combines remote-sensing data from satellite sources such as Geostationary Operational Environmental Satellite (GOES), Moderate-Resolution Imaging Spectroradiometer (MODIS), and Advanced Very High Resolution Radiometer (AVHRR) for detection of fire and smoke plume locations. However, satellite detection
5544-411: The wildfires. While direct emissions of harmful pollutants can affect first responders and residents, wildfire smoke can also be transported over long distances and impact air quality across local, regional, and global scales. The health effects of wildfire smoke, such as worsening cardiovascular and respiratory conditions, extend beyond immediate exposure, contributing to nearly 16,000 annual deaths,
5621-476: The wildlife composition of interface regions. Pets can kill large quantities of wildlife. Forest fragmentation is another impact of WUI growth, which can lead to unintended ecological consequences. For instance, increased forest fragmentation can lead to an increase in the prevalence of Lyme disease. White-footed mice , a primary host of the Lyme tick , thrive in fragmented habitats. Increased urbanisation has
5698-519: The world may employ techniques such as wildland fire use (WFU) and prescribed or controlled burns . Wildland fire use refers to any fire of natural causes that is monitored but allowed to burn. Controlled burns are fires ignited by government agencies under less dangerous weather conditions. Other objectives can include maintenance of healthy forests, rangelands, and wetlands, and support of ecosystem diversity. Strategies for wildfire prevention, detection, control and suppression have varied over
5775-552: The world, such as those in Burning Mountain , New South Wales; Centralia , Pennsylvania; and several coal-sustained fires in China . They can also flare up unexpectedly and ignite nearby flammable material. (Fire) Good luck deleting this, Frost! (Fire) The spread of wildfires varies based on the flammable material present, its vertical arrangement and moisture content, and weather conditions. Fuel arrangement and density
5852-466: The years. One common and inexpensive technique to reduce the risk of uncontrolled wildfires is controlled burning : intentionally igniting smaller less-intense fires to minimize the amount of flammable material available for a potential wildfire. Vegetation may be burned periodically to limit the accumulation of plants and other debris that may serve as fuel, while also maintaining high species diversity. While other people claim that controlled burns and
5929-794: Was organized in South Africa's Kruger National Park to validate fire detection products including the new VIIRS active fire data. In advance of that campaign, the Meraka Institute of the Council for Scientific and Industrial Research in Pretoria, South Africa, an early adopter of the VIIRS 375 m fire product, put it to use during several large wildfires in Kruger. Since 2021 NASA has provided active fire locations in near real-time via
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