Fires occurring in nature cause considerable damage to flora and fauna. People also suffer from the flames, and great damage is done to the national economy. There are several types of wildfires. In this case, the classification of fires takes into account the nature of combustion, the speed of propagation of fire and some other factors.
What are the fires
The classification of wildfires is usually built taking into account their impact on human economic activity. In this regard, forest and steppe fires, grain and fossil fires are usually distinguished. There are also agricultural burns, which are also called grass fires. The greatest losses to the economy are caused by fires in forests. They are also often associated with human casualties.
Forest fires are understood as the uncontrolled spread of fire in the vegetation zone, when the flame spreads spontaneously through the forest. Such fires occur all over the world every year and most often occur through human fault. In strong winds and dry weather, a forest fire can cover a large area.
Sometimes the causes of forest fires are spontaneous combustion of peat and lightning strikes. However, such cases are extremely rare. Most often, the flame begins to spread in places where a person appears. A fire left unattended, a cigarette butt or a match thrown on the ground are the main reasons for the spread of fire in the forest. After several days of dry weather, every dry branch lying on the ground can catch fire and cause a fire.
Classification of forest fires
Forest fires are classified according to the nature of the ignition, the speed of propagation and the size of the area of ignition. They can also be upstream, downstream, litter and underground. Depending on the wind speed, forest fires are stable and weak.
Horsefire affects tree crowns. The fire can spread very quickly over the upper floors of the forest, and in a strong wind it can completely cover all the trunks, from the crown to the litter. Young coniferous forests, in which shrubs are widespread, are most susceptible to crown fires. Strong winds and droughts increase the likelihood of this type of fire.
Forest litter, including leaves, needles, and small branches, becomes the basis for the development of a ground fire. The flame also affects the lower part of the trunks, but rarely rises to a height of more than a meter. Such a fire spreads unevenly - spots that are not touched by fire can form in humid places.
If the fire transforms into the litter or layer of peat, the ground fire takes the form of a soil fire. In this case, combustion can occur throughout the entire thickness of the humus layer and litter. In a soil fire, the roots of trees burn out, after which the trunks often fall. A fire zone of this type has, as a rule, an oval or elongated shape. Fire in the soil spreads at a low speed, but the combustion processes can go on for quite a long time.
