Horsefire: main characteristics and classification

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Forest fires occur quite often. In order for a dry tree to catch fire, just one small spark or lightning strike is enough. Considering that in most countries weeds are set on fire in the fields, the number of fires increases several times.

The larger the territory of the country, the more fires occur on it. And if a persistent drought prevails, then trees and shrubs can ignite for no apparent reason at all. There is a ground fire and a crown fire, there are also soil fires and a host of other types of fires. But first things first.

What is a forest fire

This term refers to uncontrolled fire that spontaneously spreads through the forest. In the process of such a fire, partial or complete burnout of vegetation located above ground level, forest litter (fallen leaves, branches, etc.) and fertile soil layer occurs. As a result, nothing grows in the area affected by the fire for a long time. In addition, wildfires often kill animals.

Natural disasters of this type are very dangerous, as the fire spreads very quickly over vast areas. Most often at the time of discoveryforest fire, it covers large areas, which greatly complicates the extinguishing process.

Causes of occurrence

Most often, fire appears from lightning, they account for more than 8% of fires. It all depends on the area itself. In forests dominated by young trees, natural disasters are much less common.

Another cause of forest fires is people. In some situations, fire comes from a deliberate act to kill weeds. In addition, in the spring and summer, people go to barbecue or pick mushrooms. In this case, one unextinguished cigarette or firebrand in a fire is enough. As a result of such negligence, dry grass instantly ignites, and flames very quickly spread to dry wood.

Classification of forest disasters

Based on the nature of the fire, soil, ground and crown fires are distinguished. Further, natural disasters are classified according to the speed of propagation. Based on this, the ground fire is divided into the following categories:

1. Weak. A fire up to 0.5 m high covers 1 meter of territory in just a minute.
2. Medium (height up to 1.5 m). Spreads up to 3 m/min.
3. Strong (more than 1.5m). Covers 3 meters in less than 3 minutes.

In turn, the speed of the crown fire is:

1. Up to 3 m/min. This speed is considered weak.
2. 3 to 100 m/min. In this case, we talk about the average speeddistribution.
3. More than 100 m/min. - strong fire.

This shows that a sustained crown fire spreads at a speed of over 100 meters in one minute. Accordingly, its scale is simply unimaginable.

There is also a ground fire, which also spreads quite quickly. This takes into account the burnout depth:

1. Less than 25 cm is a weak fire.
2. 25 to 50 cm is medium.
3. More than 50 cm - belongs to the category of strong.

In addition, a fire is classified according to the area of ignition:

1. From 0.1 to 2 ha is typical for a normal fire.
2. Up to 20 hectares indicates a small fire.
3. 20-200 ha is a medium fire.
4. Up to 2000 ha is typical for a major disaster.
5. Over 2000 hectares is already a disaster.

If we talk about the duration of the disaster, then during crown fires the territory burns for about 10-15 days (depending on the level of fire). During this time, more than 500 hectares can burn out. Let's take a closer look at each type of fire.

Riding forest fire

Each fire is extremely dangerous for wildlife, animals, birds and, of course, for humans. Very often, the flame reaches small grayings located near the forest. As a result, the fire quickly covers the house. Therefore, if an unusual haze appears in the sky, there is a smell of burning, then you must immediately contact the Ministry of Emergency Situations.

Horsethe fire affects the forest canopy. Most often, this type of fire results from the development of a low flame. Thus, we can say that the ground fire is a component of the top one.

The emergence of fire, which is above the surface of the soil, is facilitated by natural factors. For example, strong winds and steep slopes can cause crown fires to spread quickly. Most often, such fires occur in the summer, when dry and hot weather prevails.

In this type of fire, trees usually die completely. If we talk about the nature of combustion, then a fluent and stable crown fire is distinguished. The latter type is characterized by the fact that the crown of the tree burns out gradually, as the ground fire develops. In this case, the flame does not move along the canopy. Such fires are also often referred to as general fires. If we talk about a runaway fire, then in this case the fire, on the contrary, spreads along the canopy and can even outpace the movement of a ground fire. Also in this case, flame jumps are observed, at the moment of which the fire can hit areas at a higher speed.

As mentioned earlier, crown and ground fires are almost one. Therefore, it is worth saying a few words about the second type.

Ignition in the lower tiers

In a ground fire, the fire moves along the underlying layer. First of all, grass, undergrowth, and also undergrowth light up. A ground fire usually moves in a semicircle, forming a contour of the main flame on the ground. The result is an edge.

If we talk about the nature of fires, then bottom burning can also be fluent or stable. In the first case, the edge of the fire moves very quickly at a speed of more than 0.5 m/min. As a result, only the soil cover burns out. If we are talking about a stable ground fire, then in this case the speed of the circuit is much lower. Accordingly, not only the underlying layer burns out, but also rotten stumps and deadwood. There is a lot of smoke when this happens.

Soilfire

Underground fires affect the root system of trees. They do not have a pronounced flame. A soil fire spreads deep into the earth and can move at a speed of up to 1 km per hour. At the same time, such fires are considered the most difficult, since they are very difficult to extinguish. A ground fire causes a ground fire, which in turn provokes the appearance of a top flame.

Extinguishing activities

For firefighting, a wide variety of equipment is used: helicopters and airplanes. Thanks to the drain of liquid extinguishing compounds, the fire can be localized quite quickly. To determine the source of fire, the area is screened.

However, in some cases, annealing (backfire) is formed. It burns fire extinguishing fluids even before they arrive. In this case, a shock wave is applied. To do this, an explosion is made in front of the fire front, which initiates the appearance of a reflective screen. This will stop the further spreadflame and carry out extinguishing in standard ways.

Preventive measures

First of all, experts try to predict the occurrence of fire in a particular area, based on weather conditions and data received from the area. In this case, the forest fire coefficient is calculated.

In order to reduce forest losses, a lot of organizational measures are being taken. First of all, fire-fighting and preventive work is carried out. Sanitary deforestation is also carried out. In this case, all old and dried trees are destroyed. Forest belts that are dangerously close to settlements are also being cut down. Special trenches are laid along the line of the forest, which, in the event of a fire, will not allow the fire to pass further.

In addition, forest fires are periodically monitored, special observation masts and towers are installed. Thanks to ground observation, it is very often possible to prevent the occurrence of a natural tragedy.