The use of UAVS and helicopters in forest fires monitoring and extinguishing in hard-to-reach areas

. The paper is devoted to innovative methods for monitoring and fighting forest fires in hard-to-reach places using drones and helicopters. The main content of the study comes from the experience of extinguishing forest fires in hard-to-reach places in the southern regions of Russia . The main research is devoted to the problem of extinguishing and finding new innovative ways to prevent and extinguish forest fires in hard-to-reach places. Ecological methods of monitoring and extinguishing forest fires are considered.


Introduction
The forest, being a part of nature, sometimes is affected by various negative factors, one of these factors is a forest fire. Almost every year, especially in the summer, forests burn down from fires, thereby causing great harm to the flora and fauna, the country's economy, as well as human health. Despite the large number of preventive measures, the number of fires is growing and the main factor is anthropogenic.
For the effective functioning of a component of this part of nature, capable of maintaining and improving the health of hundreds of people, other methods are needed that are able to solve the issues of preventing, extinguishing forest fires in hard-to-reach places, reduce the total cost of extinguishing fires, and reduce the degree of environmental damage caused by the consequences. extinguishing these fires.
Russia has the most extensive forest resources that require constant protection and protection measures, which are impossible without aviation. Even 20 years ago, the federal forestry management agency annually attracted up to 700 aircraft (the flight time was more than 150 thousand hours). It can be stated that forestry was the country's largest state consumer of aviation services.
Given the special uniqueness of the mountain forests of the southern coast of Crimea and their effectiveness for the normal operation of the resort and recreational complex, it is necessary to develop an effective system of measures in the near future to reduce the risks of irreparable losses from forest fires. At the same time, it should be taken into account that the anthropogenic pressure on unique forest resources, with an increase in the number of recreants, will steadily increase. Every year in the Crimea there are about 250 forest fires, of varying degrees of complexity. Of these, about 5 are complex and difficult to access, the consequences of which cause damage, on average, about 18 million rubles. in year.
Despite the large volume of preventive measures, the number of fires is growing and the main reason is the anthropogenic factor.
The strategic task of the forestry of the Republic of Crimea is both to preserve and increase the forests of the peninsula. Basically, the forest industry of the republic is developing according to two programs -the national and regional programs for the protection and reproduction of forests, increasing their productivity and rational use, which largely corresponds to the goals of this project. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].

The purpose of paper
The purpose of the paper is to discuss the main problems of Application of innovative methods for extinguishing fires in hard-to-reach places, prevention of fire hazardous situations, reducing the degree of damage caused by fires to nature and society, the use of environmentally friendly and resource-saving methods when extinguishing fires in hard-toreach places.

Main part
Already more than once received the title of one of the best health resorts in the world, Crimea has earned not only the sea, but also others, with its great wealth, namely its forests. Very often, the main advertising motive for the arrival of tourists often becomes familiarization with the nature [17] of the Crimea.
Technologies for controlling the forest environment from a fire hazardous situation involve the use of a control system over a certain forest zone to collect information from hydrometeorological stations and posts.
Forest aviation works include: aviation protection (patrolling) of forests from fires and extinguishing them using aviation; aerial photography of forests; aerotaxation of forests; forest pathological examination; phenological observations; aerial chemical work to combat pests of forests, unwanted trees and shrubs; aerial seeding of the forest; air service for the timber industry, logging and timber rafting.
The use of unmanned aerial vehicles (UAVs) in solving forest protection tasks includes:  Patrolling local areas of the forest fund in order to detect forest fires;  Information support for ground firefighting teams;  Forest pathological examination;  Countering illegal economic activity.
Under the system it is understood that a drone controlled from the ground carries out patrolling and monitoring of the forest zone. All the information received by the robot goes to the cloud disk, where all the data will already be received and processed.
On average, the flight duration lasts up to one hour, the range is 25 km, the survey area is 3-4 km2, and the operating speed is 60 km/h. These characteristics are quite suitable for the "working" use of the drone.
Very often shooting "from above" has some problems. On some radar images, the fires are clearly deciphered, while on other images they are not visible at all, other images may be of poor quality and the fire will be impossible to distinguish from fog or clouds.
However, in fig. 1 shows a photograph taken by the Supercam S250 drone at an altitude of about 2500 m above the ground and demonstrates good quality photographic material, which allows you to notice and accurately locate the fire zone. Each forest fire that occurs in the service area is monitored from the air from the moment it is discovered until it is completely eliminated. Flying over a forest fire is carried out 2-3 times a day.
A general inspection of the fire is carried out at a flight altitude of 600-800 m. At each inspection, the boundaries of the fire are plotted on a map (map-scheme) and the date of the inspection and the area are indicated near it, which makes it possible to identify the dynamics of the spread of the fire. During the inspection of active forest fires, the UAV operator determines the main direction of the spread of fire, the presence of a threat of fire spread to economic facilities and settlements, the presence of separate combustion centers, areas that are especially dangerous in terms of fire, the place where the fire passes through mineralized strips, and, if possible, identifies the location of people and technicians employed in extinguishing the fire in order to determine the correctness of their placement on the edge of the fire. Simultaneously with the receipt of video information, representatives of the forestry service make decisions on tactical methods of extinguishing, maneuvering human and technical resources. Natural boundaries are outlined to stop the fire, access roads (approaches) to the fire, a section of the edge (roads, trails, lakes, streams, rivers, bridges) [18][19][20] .
A detailed inspection of an active forest fire (control over the work of forest fire teams) is usually carried out from a height of 200-400 m. From this height, mineralized strips laid by forest fire equipment are clearly visible.
If the forest fire equipment is equipped with "radio beacons" from the UAV kit, then when the UAV is flying in their coverage area, it is displayed on the screen of the ground control station.
The project assumes that all photos from the drone will be sent to a cloud drive (the data is sent directly to the Internet). After being received on the server, the photos will be processed to determine the fire situation in the region.
In the event of a fire that has already occurred, it is assumed that the drone will observe the fire from the air, from the moment it appears until it is completely eliminated. Fire monitoring will be carried out 2-3 times a day, and based on the collected images, it will be possible to carry out more justified and effective fire extinguishing actions. When a fire is detected from a drone, information is sent to the server, data processing allows you to send a request to extinguish from a helicopter. To date, there is a diverse list of means and methods of combating this natural disaster, among which are: carbon dioxide, motor pumps, incendiaries, a blower, APU-5, aircraft, etc.
At the moment, the technology of extinguishing forest fires with water and foam expelled from an air vehicle is already outdated. The very technology of such fire extinguishing assumes that most of the water or foam dropped from a height is dispersed in the air and evaporates in the air streams rising above the fire. Drops of water that have flown evaporate on hot coals, only for a while, lowering the temperature. And the disadvantage of this device is its limited use due to the impossibility of its use in hard-to-reach places and for extinguishing large-scale fires [21][22] .
The use of aviation fire extinguishing equipment, namely tanker aircraft and helicopters with pouring devices, is not always effective, with their help it is rather difficult to provide a sufficient flow of water to the combustion source, part of the water evaporates and is carried away by the ascending heat flow. In addition, most fire extinguishing methods cause irreparable harm to nature, disrupting the ecological situation of the area, the restoration of which can take more than 100 years.
Experience shows that fires can appear in places that are hard to reach for the delivery of water, dispersed and foam fire extinguishing agents supplied using stationary fire extinguishing installations, while they are inactive when numerous "shadow" zones are formed. Therefore, special attention is paid to fires that have arisen in hard-to-reach places. Due to their specificity, they are difficult to detect, get to the place of fire, and are almost impossible to put out by classical methods. Very often, such fires are caused by lightning discharges, in frequent cases there is a human factor. Being on a steep slope, in a gorge and other hard-to-reach places, a fire begins to flare up and cover larger areas, while a person is practically powerless. Therefore, at the moment the situation requires modernization and the introduction of innovative methods of extinguishing fires.
The innovative fire extinguishing technology proposed in the project can be used to extinguish fires in hard-to-reach and remote places, as well as crown and ground forest and steppe fires. By itself, the technology of extinguishing fires in hard-to-reach places involves a helicopter equipped with special equipment with "fire-fighting" missiles (Fig. 2).
Being above the source of fire, in a hard-to-reach place, the helicopter fires a volley of four barrels of fire-fighting rockets. The fire-fighting rocket is made of environmentally friendly materials, filled with a fire extinguishing agent, equipped with a dispersive charge, and a sensor of the selected parameter.
The rocket fires directly on the ground, which makes it possible to more effectively extinguish the fire. When the detonator in the rocket fires, due to increased temperature or flame damage, the package with the TEAS foaming agent breaks, which, mixing with water, fills the barrel. The reaction of the reagents forms a foam that covers the combustion center, thereby extinguishing the fire and suppressing combustion. At the same time, the surface is not turbulent, a directed impact is carried out by knocking down the flame, volumetric penetrating cooling, inhibition, localization and complete suppression of fire on an area of 150-250 m2.
In case of fires that have arisen in hard-to-reach places, as well as when such fires flare up over hundreds of hectares, it is advisable to use air delivery of fire-suppressing missiles placed in a transport, heat-resistant container suspended by a helicopter, which delivers the necessary cargo to the fire sites.
In total, the hanging container will contain 28 missiles (5 rows of 4 missiles). As we can see from the figure, the aircraft ( 2), in this case a helicopter, brings the extinguishing agent, namely fire rockets (1), directly to the place of ignition. With the help of thermal sensors located on the rocket or when it hits the ground, it breaks (4), when this device explodes, the reagents necessary for extinguishing (5) are released, which help a person to cope with a fire. Fig. 3. Extinguishing a fire in a hard-to-reach place using rocket technologies If the fire spreads to a larger area, then subsequent volleys are fired from the helicopter until the fire is completely suppressed or the supply of fire extinguishing agent in the platform is completely consumed.
In case of large fires, the aircraft descends to the base to reload the platform and continues to participate in the extinguishing process.
At one time, this method was developed by Subratov A.A., but no monitoring system was proposed at that time.
The technology of fire-fighting rockets assumes that a helicopter drops a rocket, which has all the fire-fighting reagents, onto the fire site; during the explosion, the extinguishing material is scattered over 150-250 m2. With only one fire-fighting rocket, it is possible to put out a medium-sized fire. The entire complete set of missiles is enough to extinguish largescale fires. At the same time, rockets are made of environmentally friendly materials, which allows us to conclude that this method is environmentally friendly.

Conclusion
The implementation of these innovative technologies within the framework of the project will bring great benefits to nature and people. Along with health-improving factors, the Crimean forest brings great aesthetic pleasure from communicating with wildlife. The damage from forest fires is practically incalculable, as it has numerous negative consequences, the main of which is the practical non-renewability of these losses. The monitoring technology will make it possible to control areas of increased fire hazard from the main ignition factors, regardless of the season. By means of a drone, it will be possible to control large forest areas. By monitoring fire hazardous areas on a daily basis, we reduce the risk of fires.

Acknowledgment
The reported study was funded by RFBR, project number 19-29-06081