Forest fire - SpeedyLook encyclopedia

A forest fire ( FdF in jargon fireman) is a Incendie which touches a wooded massive .

It can be of natural origin (due to the Foudre or an eruption ic Volcan) or human (intentional and criminal or involuntary and accidental starting from fires agricultural or lit for “ maintenance ” of Layon S or the open zones for the Chasse).

By ecological concern, when the medium, the context and the legislation allow it, one can locally use “fires controlled” ;

to burn a high-risk zone of fire before it is too dry,
to maintain certain habitats necessary to certain species which require fires (some insects and mushrooms lives on wood flarings)
to restore diversity écopaysagère certain mediums become very homogeneous in order to restore there a habitat for the species pionnières.

The majority of fires are voluntary (deforestation at end of setting in culture), criminals or originate in an imprudence (Barbecue, cigarette end of Cigarette, fire of burn-beating).

Forest fires are at the origin of a Air pollution, water and grounds.

Legislation

In certain forests at the risk, fires can be prohibited all or left the year, just as the Fireworks in timbering and with its accesses.
Dans the Forests of war and other zones containing of the not exploded Ammunition, fires can are generally prohibited all the year (ex Forêt of Verdun in France)
De many countries have a legislation prohibiting or regulating the burning of the Déchet S with the free air (including agricultural and forest in certain cases), as much because some of these burnings were at the origin of serious and persistent pollution (Dioxine S, PCB, Furane S, Heavy metals, etc), that to protect the mediums.
Dans certain natural environments protected and managed for the Biodiversity, a payment can impose the burning of the plants cut on sheet before export out of the site (so that ashes do not enrich the ground by supporting there a Eutrophisation or unfavourable Dystrophisation with ecological diversity.

Physical damage

It is estimated that burned surface each year is approximately (NB: 1 km ² = 100 ha):

Israel: 35 km ², is 0,17% of the territory
the United States: : 17400 km ², are 0,18% of the territory
France: 300 km ², are 0,05% of the territory and 0,16% of the forest
Greece: 271 km ², are 0,20% of the total territory.
Spain: : 1570 km ², are 0,31% of the territory

2005: more: 1300 km ²
eleven firemen died the July 17th, in a vast fire in the Province of Guadalajara, in the center of Spain. Fire, undoubtedly of with the negligence of several young people who would have badly extinguished their barbecue, devastated more than 120 km ² of forest.
be 2006: : 175486 hectares destroyed in Galicia

Portugal: 426 km ², are 0,46% of the territory (study undertaken over the period 1956-1996 by FAO)

1991: : 1820 km ², are 2% of the territory
2003: : 4249 km ², are 4,6% of the territory; 20 dead;
2004 : : 1205.3 km ², are 1,3% of the territory
July 2005: 300 km ² of vegetation already left in smoke. Six firemen died more than 130 were wounded. 416 supposed pyromaniacs were stopped since the beginning of the summer.

Indonesia: From September to November 1997, large fires devastate for two months the forests Indonesia born, sufficient rejecting smoke in the atmosphere to cover all the areas with a fog which reached the south of the Thailand and the Filipino in north, the Malaysia and Singapore being particularly touched. A surface equivalent to that of the Costa Rica was entirely shaven. “The experts agree to recognize that large forest fires of 1997/1998 in Indonesia were a world ecological catastrophe. ”
Italy

According to a report/ratio of FAO, Italy has: 8300 fires per annum on average (1962 - 1996) which burn an average surface of 940 km ².
1993 : : 2300 km ², are 0,76% of the territory

Morocco

According to the statistics of the service of forest fires an average of: 3035 ha are annually burnt.

Canada: The forest zone in Canada is important in all the provinces except the south of the provinces of the Canadian Prairies like with the Island-of-Prince-Edouard (IPE) purely agricultural. The forests in the south of the parallel 55^e are in general marketable and the service of fight to the fires is developed there. More in north, forest fires are not controlled with less of threat for the localities. Thus the number and the surface touched by forest fires seem enormous with the Yukon (YK) and with the Territoires of the North-West (TNO) but it is only of the forest of Taïga or Toundra in general not exploited. The burnt surfaces shown on the graph are absolute and nonproportional to the surface of each province.

* Quebec (QC in the graph): on average more than 800 fires according to SOPFEU. The average varying largely between the dry years and those wet.

* Other provinces and territories on the chart and not mentioned above:

*CB: Colombia-British, AB: Alberta, SK: Saskatchewan, MB: Manitoba, ONE: Ontario, NB: New Brunswick: Nova Scotia, TN: Ground-New-and-Labrador, PC: Parks Canada.

Ecological damage

The fires are normal in forest where they kill out of many animals not-wheels or incompetents to flee, but if they are abnormally frequent or violent one, they affect the ecological capacity of Résilience of the ecosystem. Thus in Southeast Asia, Africa and locally in South America, of many voluntary fires contribute to the Déforestation and sometimes to the turning into a desert and/or phenomena serious of erosion (with Madagascar for example).

They seem moreover to be of important factors of pollution, ignored, strongly varying according to the type of forest, fire and the moisture of the plants;

Air pollution: the satellites show the dense plumes of Aérosol S which cause a specific or chronic pollution until several hundred km of their origin. The analyzes detect in smoke of the polycyclic aromatic Hydrocarbures (HAP) and of the volatile Composés organics (COV), of the Goudron S and the Suie S Cancérigène S, more especially as wood was wet. One suspecté that near the seas (or after the sea water droppings by Canadair S), the Chlore resulting from salt contributed to produce Organochloré S poisons such as Dioxine S and Furane S. the Ineris analyzed into 2003 smoke of some fires corresponding to a surface cleared of undergrowth of 4 m ², in a combustion chamber of 80 m ³ surmounted by a hood of extraction of smoke: the dioxin emission and furans were on average of 10,5 ng I.TEQ/kg of burned biomass (from 1,0 to 25,9). In this experiment, it is not the combustion of the plants collected close to the sea, but that of those which were wettest which produced the most pollutants (CO, Nox and COVT) and the organochlorinated ones. On the other hand the very dry plants if they emitted much less CO and COVT while burning, produced much more Nox. But they were not alive trees, and the temperatures did not reach those of the large fires. Heavy metals and radioactivity: the combustion of trees having bioaccumulé of the Heavy metals or the Radionuclide S (for example after the nuclear tests in the atmosphere or the passage of the radioactive cloud emitted at the time of the Catastrophe of Tchernobyl, following the Nuclear tests in the atmosphere or having pushed on grounds naturally radioactive is source of pollution metal. The Lead (widespread in forest following its use in the Ammunition S of hunting and war, as well as the mercury are particularly volatile at temperatures much lower than those reached by forest fires.

photochemical Pollution: the producedes gas interact with the solar rays UV to produce a pollution known as photochemical

Gas with greenhouse effect: forest fires reject large quantity of (Carbonic gas), powerful Gaz with greenhouse effect. Moreover, the fire supports the scrubbing of the organic matter of the grounds which were part of the forest carbon well. However, if combustion were slow (in wetland and rainy), the charcoals, incorporated on the ground will temporarily contribute to adsorb and stabilize some Toxique S, time that they are degraded by the microbes and mushrooms of the ground, which supports the restoration of the substrate. This charcoal could have thus played a part in certain poor tropical grounds where the appearance of an abnormally rich and productive ground, the Terra lent seems to them to some extent dependant.
Des fires too frequent can select certain species resistant to fire and a less restoration of the grounds.

In 2007, except sometimes CO2 as gas with greenhouse effect, these pollutants are still not entered in the national land registers and inventories (However, only in French metropolis, of 1980 to 2000, they are 5218 forest fires per annum and 30738 hectares burned per annum which were sources of a not measured air pollution nor evaluated.

Mechanism

When water reserves of the ground are between 100 and 30%, the evaporation of the water of the plants is compensated by the water drawn from the reserve of the ground and a little by the phenomenon of dew. Below this threshold, the plant cannot be hydrated any more and in fact the gasolines of the plant evaporate. In the event of prolonged dryness, there is thus on the one hand an atmosphere containing of the flammable gasolines, and on the other hand very dry plants thus very flammable.

The plants pushing on grounds Silice ux (as the maquis) are for this reason less state than the plants pushing on ground Calcaire (like the Garrigue).

Once declared, fire can progress

by bottom, in “crawling” (propagation by the Broussaille S, organic remains on the ground);
by the summits;
by ignited elements carried by the wind; it can thus “jump” a fireproof zone like a Route, even a Autoroute.

On a flat ground and with a homogeneous vegetation, it is propagated in form of ellipse, in the axis of the Vent. In the South-east of the France, one estimates that it progresses to approximately 3 to 8% the speed of the wind according to the grounds (slope, density and nature of the vegetation).

Although one is in the open air, it can occur in certain cases a Embrasement generalized flash (EGE, or flashover ), had with the accumulation of a gas pocket of Pyrolyse; one can thus see more than 50.000 m ² blazing up instantaneously ( details in the article on the EGE ).

Causes

unknown Causes 30%,
natural Causes: the the Lightning. This represents in Mediterranean zone approximately 2% of initiations of fires. On the other hand, this proportion is much higher in other countries where the forest recovers a large territory. For example, it reaches 30% with the Quebec and burns there more large surfaces.
involuntary human Causes: they can at the same time be imprudences or accidents the circulation type in forest or periphery, electric lines, garbage dumps, burning the remanent ones,… 43%,
voluntary human Causes: it can be a question of pyromania, revenge or government scheme or administrative 25%

Management of forest fires

Forest fires present several difficulties:

the approach of the hearth is difficult because of the broken Terrain and the vegetation;
the hearths are very wide, even multiple in the case of cases of arson;
fire progresses very quickly and can encircle the helps.

The risk of appearance of forest fires is particularly important at the time of the Sécheresse S.

Prevention

The prevention includes/understands measurement such as:

the maintenance of the solid mass wooded: elimination of the trees in excess, creation of Cut S, which, failing to prevent the progression of fire, allows the progression of the machines and ensures of the zones of fold; obligation for the owners to clear of undergrowth;
apart from the season at the risk (thus primarily in Winter), one can practice burnings like alternative to the cuts: they are controlled fires intended to make “alleys” in the forest;
prohibition to make fires, together with measurements of sensitizing, information and repression (police surveillance);
the installation of watchtower in critical period and the presetting of means (turns of monitoring, inflatable water tanks, guet air armed with planes bombers of water…) ; the monitoring can be also carried out with kinds of airships (Hellion project);
establishment of plane of intervention and engagement of means.

One can measure the impact of maintenance by comparing two solid masses: the forest of the Moors of Gascogne (10 000 km ²) and the Massive of the Moors (335 km ²); this last, although smaller, is prone to devastations much more important. In the first forest, the requirements of maintenance correspond to the economic interests (exploitation of the pine of the Moors). In the second case, maintenance encounters conflict interests: lobby of the Hunting the USSR which is opposed to clearing of undergrowth (sheltering underwoods of the Sanglier S), the Maire S which authorize the construction of dwellings isolated to attract capital, the abandonment of the Chêne-liège to the profit of the pine, more profitable but more easily flammable…

The organizations of weather monitoring (for example Weather France) play a key role by announcing the moments when the risks are maximum (dry and windy time). In 1976, the Canada developed an empirical model of calculation of risk; France was inspired some for calculation by the IFM (Indice forest weather) which quantifies the risk.

Fight against the fire

Forest fires in France

In France, the forest accounts for approximately 28% of the territory 189 000 km ²; the largest forest is the forest of the Moors of Gascogne, it extends on 10 000 km ² whose majority are in the Landes (6 193 km ²), it are planted to 97% of pine S. forest fires devastated 60.000 hectares in 2003, which has been regarded as the worst years for 30 years.

One uses the term Défense of the forests against the fire ( DFCI ); one speaks about “coordinates DFCI” to locate the main forests, of “ways DFCI” for the access to these solid masses…

In addition to the firemen, the State employs forest workmen specialized in the DFCI (Working repatriated foresters of North Africa and Auxiliaires of protection of the Mediterranean forest) framed by warrant officers of the National office of the Forests, with vehicles water carrier yellows, vehicles of framing and entry of charge, turns of guet in high points and specialized teams. Various services are provided by the civils servant of the ONF according to the departments at the request of the Forest Services of the State of Departmental managements of agriculture and forest (DDAF): Forest cell of Support on large fire (data-processing cartography on line of fires and assistance to the forecast), Teams of guidance of the means and recognition, Equips Multi-field with Investigation on the Origin with Forest fires (mixed team of investigation foresters - gendarmes), team of tactical fires, etc the territorial collectivities employ also territorial agents called forester-sappers (yellow vehicles) trained by the ONF in the beginning, but taken again by the departments following the disengagement of the State, as well as the voluntary ones gathered in communal Committees of forest fires (CCFF, orange vehicles).

The terrestrial vehicles specific to the fight against forest fires are:

the tankers forest fires (CCF): a cross-country vehicle (4×4) with a device of self-protection when the vehicle is encircled by the flames (pressurized cabin and sprinkler device of the van);
the tankers great capacity (CCGC): Truck articulated (superheavy) being used as water reserve to feed the CCF.

The firemen have a “batch of fold” which enables them to protect a minimum if they are trapped out of the vehicle. It is composed of a hood with a filter cartridge (standard Gas mask) - forest fires are attacked without Breathing apparatus insulating - and of a “Poncho” metallized which makes it possible to be protected from radiated heat.

In summer period, the units of firemen of the departments at the risks (wooded departments of the South of France) are reinforced:

by seasonal firemen: they are voluntary firemen other departments which come to take vacations in the barracks of these departments;
of the groups of intervention of forest fire (GIF): they are columns of vehicles, armed by firemen in general professional, sent by the departments at the weak risk towards the high-risk departments; in addition to CCF, the columns include/understand vehicles to ensure logistics - in general two or three vehicles all-utility (VTU): material of replacement, mechanics, food and drink - and in the ideal a VSAV armed with a Male nurse fireman, possibly a Vehicle radio-médicalisé (VRM) with a doctor fireman (MSP), and a mobile headquarters (vehicle PC).

Forest fires in Quebec

In Canada, each province is responsible for the protection of the forests. In Quebec, it is the SOPFEU which is in charge with prevention, the detection and the extinction of forest fires. The organization is similar to that of France.

The underground fire

It happens that a forest fire can ignite peat and brood several weeks (in the ground of heather or the surface peat) even more than one year and until one even up to five meters of depth in the boggy layers of a tropical ground (Certain fires thus could brood during the rain season in Indonesia). Chemicals (Coalex system: coal extinguishment, for “extinction of fires of coal or coal”) exists, considered to improve from 5 to 7 times the performances of water. The ground can be dynamited and the peat thus updated buried under wet sand, if possible, in full rain season. A wooded Terril containing coal can also enter in internal combustion and kill the trees which pushed above, in general without producing of fire.

Sylviculture, afforestation, ecology

Forest fires belong to a natural dynamics in the forests the Mediterranean born: many plants adapted there, certain even need fire to live. These fires however cause economic damage important and present a danger to the man. Their too great repetition impoverishes the grounds and modifies in an irreversible way the biological state characteristic of these forests.

Previously, fires of natural origin were less frequent. The habitats of fauna and the flora were not split by the human establishment and took part in the recolonisation of the adjacent spaces touched by fire. This natural regeneration is slowed down and impoverished by the fractionation of the habitats. The recolonisation by the species is then partial: the Biodiversité of the zones decreases with the risk of extinction of certain species like the Tortue of Hermann.

This fractionation of the habitats takes several forms (Autoroute S, new dwellings…), but the causes are almost always the same ones, the urban spreading out (around Toulon for example): the development of the second home and the Tourisme requires Infrastructure S and grounds, therefore it y' has artificialisation of the grounds and fractionation of the habitat.

The causes of the fires are varied, they go from the brakes of the Train S to the Mégot S thrown négligemment of the window of a car while passing by the Barbecue S savages and the glares of Verre making Loupe, and especially the flamers.

But another cause seems to take shape: in fact the climatic modifications involve a fall of precipitations on these Forêt S and thus an increase in the Incendie S.

Gasolines involve in the fires

They vary according to the countries, the seasons, the ground and the percentage of high ligneous family.

Certain gasolines burning easily and diffusing fires are known as Pyrophile S . They are often gasolines with rapid growth such as the woodland Pin and the Eucalyptus, but also the Bruyère, or the Ciste of Montpellier or the Arbousier in moderate and/or Mediterranean zone. They have a low capacity to collect deep water, and physiological characteristics (resin, flammable gasolines). Some of these species, continuation probably with the natural selection, resist recurring fires better, that they sometimes then seem to be able to support while burning easily, while protecting their seeds and/or their capacity to make rejections.

There exist conversely gasolines resisting the fires better, known as pyrorésistantes . They are for example it (arborescent Bruyère, the Pin of Alep, the Holm oak, the Châtaignier or the Chêne cork).

The responsibility compared for the Leafy S and Résineux is discussed, because so in laboratory, coniferous timber seem less to propagate fire that the oak for example, this always does not seem to be checked in nature. Various external factors with the tree and the gasoline are to be considered;
En Mediterranean zone, the olive-tree which burns badly is considered to make a good firebreak and to slow down the fires. The agricultural cuts, whose Vine S, Orchard S, meadows and cultures is famous capacity to block or slow down forest fires, but their Impact S differed in the space and long-term via the drainage and of the water call for their Irrigation are still badly measured. They seem that the Bocage seldom burned and burns, even when it are trees planted on slope, perhaps because it supports a better retention of water on the piece at the time of the rains.
La generalization of monocultures équiennes (of the same age group) of Eucalyptus or Résineux seems to have supported forest fires, especially on poor grounds and inclined, on draining substrates (sand) and/or beforehand drained (ex: Moors in France).

A naturally high Biodiversité seems to improve the capacity of the grounds and the forest ecosystem to use water and to exploit it with different depth, including in the form of Rosée or condensates of fog, as in the west of the Peru where it sometimes never rains during the year, but where the fog presents almost each morning streams on the trunks, so much so that the first Spanish explorers named certain trees " trees with pluie". In the zones where the fog is frequent, many gasolines (and their épiphyte S) effectively collect “ the horizontal rain ”; or more exactly, they condense on their sheets, branches and trunks the steam brought of the sea, or by the fogs. Until 1000mm/an in the rainy forest of bay-trees of the park of Garajonay of the island of to the the Canaries Will gum). This water which streams along the trunks does not create erosion on the ground, and it supports the creation of a humus rich and able to store it.
Sur the equatorial belt , zone which receives the most solar radiation, of Borneo to Amazonia, it seems that the billion spores and certain molecules emitted by the tropical trees and their épiphytes (foams, ferns, lichens in particular…) also contribute to nucléer, to condense and weigh down the water drops which then form dewdrops, rain or streaming of condensation, allowing to recover a big part of water évapotranspirée by the trees.

The not exploited biodiversifiées moderate forests also produce a Humus richer and thick that of the cultivated forests, richer in Mycélium S and more diversified microfaune. The gasolines are complementary the ones there the others for a prospection improved of water in all the compartments of the ecosystem and on all the levels of under ground accessible to the roots, grace in particular to their mushrooms symbions and mycorhisateurs. The biodiversity also seems to allow better a ecological Résilience, limiting the risk of rapid return of fire. Animals défoliateurs (caterpillars défoliatrices, Locust pilgrim, etc even of the insects weakening then killing the trees weakened by the hydrous stress (ex: Scolyte) could also in period long or serious dryness to play a part by slowing down or blocking the evapotranspiration trees, and thus by protecting the water resource from the ground.
La diversity of the forest gasolines decreases naturally and drastiquement in the extreme mediums (circumpolar, high forests and sub-Saharan, it is then genetic diversity within the populations of trees which could then have a certain importance, just as their interactions with other species influencing the control of water.)

When the medium is dry and that a fire is launched, there do not seem to be gasolines or varieties more adapted genetically which can attenuate the power of fire. They are then the nature and the structure (horizontal and vertical) of the forest and its edges, and the nature of the cuts which it is necessary to consider for their important role. Certain cuts have a true role of firebreak, but can paradoxically if they are badly conceived or badly positioned to have a dehydrating impact or in certain cases to poke the flames by an effect of conduction of the wind.

Regeneration of the forest

Certain types of habitats depend on the fires to maintain a high Biodiversité: it is the case in particular forests of Pin of the marshes. These forests, primarily present in the South-east of the the United States, can be regenerated fully only in the presence of regular forest fires, without what of the species of trees Feuillu S not very resistant to the fires but very good candidates takes the top.

Regular and controlled fires are thus set up in such forests. These forest fires are practiced under particular conditions of temperature, wind and moisture, in order to be able to control them and not to upset or endanger the dwellings around.

Town and country planning

August 1st

Recommendations concerning forest fires

Respect the regulation of the use of fire in forest.
you with the town hall of your residence for the authorized periods Inform.
do not borrow the tracks reserved from the first-aid organizations.

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