Fires are commonly referred to as uncontrolled combustion processes. Forest fires the same process, but in an area densely planted with trees. Forest fires are common in green farms rich in grasses, shrubs, dead wood or peat. The causes and consequences of such disasters vary from region to region.
Fossil coal indicates fires started shortly after land plants appeared 420 million years ago. The occurrence of forest fires throughout the history of terrestrial life suggests that fire must have had a pronounced evolutionary impact on the flora and fauna of most ecosystems.
Types and classification of forest fires
There are three main types of forest fires: top, ground and underground.
Horsemen burn trees all the way to the top. These are the most intense and dangerous fires. They tend to severely affect the crown of trees. It is worth noting here that such a fire in coniferous forests is the most dangerous because of the strong combustibility of trees. However, it also helps the ecosystem because once the dome has burned down, sunlight is able to reach the ground, sustaining life after the disaster.
Ground fires burn the lower tiers of trees, shrubs and ground cover (everything that covers the ground: foliage, brushwood, etc.d.). This is the lightest type and causes the least damage to the forest.
Underground fires occur in deep pockets of humus, peat, and similar dead vegetation that become dry enough to burn. These fires spread very slowly, but are sometimes the most difficult to extinguish. Sometimes, especially during a long drought, they can smolder underground all winter, and then reappear on the surface in the spring.
Photo crown forest fire
Causes
Forest fires can be caused by natural and man-made causes.
Natural causes mainly include lightning, volcanic eruptions (active volcanoes in Eurasia), sparks from rock falls, and spontaneous combustion. Each of them is a source of ignition of trees. Favorable conditions for the spread of a forest fire are due to high temperature, low humidity, an abundance of combustible materials, etc. d.
In terms of man-made causes, a fire in a forest can break out when an ignition source such as a flame, cigarette, electric spark, or any other source of ignition comes into contact with any flammable material in the forests due to human negligence, negligence, or intent.
Characteristics of fires
There are a number of characteristics of forest fires. Let’s take a look at them briefly. As mentioned above, according to the nature of the ignition, forest fires are divided into: riding, grassroots and underground.
According to the speed of advancement, top and bottom fires are divided into fugitive and stable.
Weak is considered to be an underground fire that hit no more than 25 cm. Medium 25-50 cm, and strong if more than 50 cm burned out.
Forest fires are also divided depending on the zone of their distribution. A fire is considered catastrophic if the area covered by the fire element exceeds 2000 hectares. Large fires include fires on the territory from 200 to 2000 hectares. 20 to 200 ha disaster is considered medium. Small from 2 to 20 ha. A fire is called a fire that does not go beyond 2 hectares.
Putting out forest fires
The behavior of fire depends on the method of ignition, the height of the flame and the spread of fire. In wildfires, this behavior depends on how the fuel (e.g., needles, leaves, and twigs) interact, the weather, and the topography.
Once an ignition has begun, it will only continue to burn if temperature, oxygen, and a certain amount of fuel are present. Together, these three elements are said to make up the “fire triangle”.
To extinguish a fire, one or more elements of the fire triangle must be eliminated. Firefighters should do the following:
In conclusion, burning elements are removed, trees are cleared before the oncoming fire.
Effects
Fires are a major cause of land degradation and have numerous adverse environmental, economic and social impacts, including:
The ozone layer is also depleted.
Forest fires in Eurasia
According to statistical reports for the period from 1976 to 2017, from 11,800 to 36,600 forest fires are recorded annually in the protected area of the Eurasian Forest Fund on an area from 235,000 to 5,340,000 hectares (ha). At the same time, the area of forests annually attacked by fire ranges from 170,000 to 4,290,000 ha.
Forest fires cause irreparable damage to natural resources. Fires of this type range from 7.0% to 23% of the total area of the forest fund annually subjected to fire attacks. On the territory of Eurasia, ground fires are the most widespread, causing damage of varying intensity. They occur in 70% 90% of cases. Underground fires are the least common, but they are the most destructive. Their share is no more than 0.5% of the total area.
Most forest fires (over 85%) are man-made. The share of natural causes (lightning discharges) is about 12% of the total and 42.0% of the total area.
If we consider the statistics of the appearance of fires in different areas of Eurasia, then in the European part they happen more often, but on a smaller area, and in the Asian part, on the contrary.
The northern regions of Siberia and the Far East, which account for about a third of the total area of the forest fund, are located in uncontrolled territory, where fires are not registered and are not turned into statistical data. Forest fires in these regions are indirectly estimated from state forest inventory data, which includes information on burned areas in all forestry and Eurasian entities.
Prevention of forest fires
Preventive measures will help to avoid this kind of phenomenon and preserve the green wealth of the planet. They include the following:
It is also important to inform citizens about safe behavior with fire.
Monitoring
- Monitoring, as a rule, includes various kinds of observations and statistical analysis. With the development of space technologies in the world, it became possible to observe events from a satellite. Along with observation towers, satellites provide invaluable assistance in the detection of fire points.
- The second factor is that the system must be reliable. In an emergency organization, this means that the number of false alarms should not exceed 10% of all observations.
- The third factor is the location of the fire. The system must find the fire as accurately as possible. This means that the allowable accuracy does not exceed 500 meters from the actual location.
- Fourthly, the system should offer some estimates of the spread of fire, i.e. in which direction and at what speed the fire is moving forward, depending on the speed and direction of the wind. When regional control centers (or other fire authorities) receive public smoke observations, it is important that the authorities are aware of the general pattern of fires in their area.
