TV Systems for Early Detection
of Forest Fires in Leningrad Region,
(IFFN No. 23 - December 2000, p. 108-109)
Leningrad region is located in the Northwest of Russia. Its territory covers about 90 000 km2. Federal forests occupy about half of the area, i.e. 45 000 km2 which are managed by 27 forestry enterprises under the supervision of the Leningrad Region Forestry Committee, St. Petersburg. Almost 1 000 forest fires occur annually in the forests of Leningrad Region. They are caused by human activities, some of them by arson. The average area burned annually makes up 1 000 to 1 200 ha.
Until recently the detection of forest fires basically has been carried out by one of the divisions of the Russian Aerial Forest Fire Protection Association (Avialesookhrana) and by the ground services of the forestry enterprises. Since 1996 priority in forest fire detection was given to develop and install ground-based TV means for early detection of forest fires. At the end of 2000 the territory of Leningrad Region is covered by a network of 50 observation towers and masts that are 35 to 45 m high and equipped with colour video cameras for circular survey. Each of these lookout point surveys an area covering an observation radius of 15-20 km through the whole fire season (May to September). In order to cover the whole territory of Leningrad Region a total of ca. 110 of such TV installations are needed.
The extreme dry summer of 1999 experienced an increase of the area burned (11 000 ha). The districts which had not yet been equipped with TV fire detection systems sustained the heaviest losses. The wet summer of 2000 was rather quiet. However, the only large-scale forest fire (ca. 400 ha) originated early in summer in the south of the region where there are still no video systems for forest fire detection.
System Design and Functioning
Each TV lookout point for forest fire detection comprises:
- observation tower (35-45 m high)
- video camera on a rotary unit with azimuth indicator
- operators place with remote control of the video camera, colour TV monitor (the current azimuth is indicated on the screen against the background of the surveyed territory)
- telephone and UHF radio communication means for the information transfer on the fire detection, for dispatch and coordination of fire fighters, and for communication with the neighbouring TV lookout points
- fire-plotting map with the indication of location and geographical coordinates of an observation tower and an azimuth circle at the boundary of the video camera survey radius
Three types of observation towers are used:
- stationary, 35-45 m high, built on a concrete foundation
- collapsible, 32-36m high, made of prefabricated elements which can be assembled right on the ground during one working day, together with the video system
- mobile, 22-35m.high, with a hydraulic telescopic elevator that which is located on the chassis of a heavy off-road capability truck
Stationary and collapsible towers are set up not more than 250 m away from the operators building. Mobile towers can be freely moved around the territory under survey, considering local conditions of fire danger; they are self-contained and provide the operators place in a sheltered trailer.
In the forestry enterprises of Leningrad Region specialized forest fire video systems Klen (Velikiy Novgorod) and Baltika (St. Petersburg) are used. Improved methods for fire detection were elaborated in the St. Petersburg Forestry Research Institute and approved by the State programme in 1995. The improvements include:
- Video system power supply is 220V 50Hz
- The accuracy of fire bearings are +/- 3.0° (Klen) and +/- 0.5° (Baltika)
- A 120-mm lens provides 15x magnification
- The video camera is remotely controlled by means of an additional pair of wires (Klen) or through the video cable (Baltika)
- Ten functions are carried out from the control desk including remote orientation of video camera
The greatest effect from the use of forest fire video systems is achieved by a network of lookout points located at spacing distance of 12 to 20 km, depending on the relief. Each video system operator controls an area of 70 000 to 80 000 ha. The integration of network data allows the determination of fire locations by cross bearing. A stable smoke column appearing above the crown layer is confidently recognized from a starting fire with the area of 10 to 30 m2. Such early detection allows initial attack and fire suppression before the burning area exceeds 50 to 100 m2. Problems are faced only by multiple simultaneous ignitions and a lack of firefighting resources. Altogether the introduction of early fire detection devices considerably reduced the area burned.
In the recent four years several forestry enterprises of the Committee invested own funding (ca. $US400 000) into the development of forest fire radio communication and television-based fire detection systems without financial aid from federal authorities.
Considerably damages to the forest fire video systems are caused by atmospheric discharges. Even when switched off from power supply video cameras are hit through the cable line. Direct lightning blows were not registered. Almost ten percent of all running video systems have been affected by thunderstorms. The latest video system model Baltika-3 is already provided with lightning protection. Other problems have been caused by birds that have damaged the video system by pecking plastic gaskets of video cameras, resulting in penetration of water into the system. Rubber gaskets are not touched by the birds.
Mobile video systems face problems of properly determining the distance to the detected fire spot. The late model Baltika-3 provides an accuracy of locating a fire of +/- 500-700 m within its range of 10-14 km. Since Russian forests are divided into square compartments of 1x1 km size (planning quarters) the accuracy of fire detection within a certain quarter is considered to be sufficient.
The creation of the completed network consisting of 110 TV installations for forest fire detection on the territory of Leningrad Region will lead to a considerable reduction in losses caused by forest fires due to rapid intervention. In addition the number and time of expensive flights of patrol aircraft and helicopters can be reduced. Early detection of forest fires by means of television, supported by active fire suppression from the air will increase the efficiency of forest fire control. Aerial fire suppression still is not yet being used widely in the north-west of Russia. However, advanced technologies exist and have been tested, such as helicopter equipment for pressurized discharge of liquid fire suppressants (up to 15 m3) using a foam generator, as well as infrared sighting device which considerably reduces the number of misses of the spot and at the same time provides automatic discharge of fire suppressants from airtankers. Since the fire season in the north-western part of Russia lasts for 4-5 months per year there seems to be a possibility for transferring forest fire video systems together with collapsible and mobile masts to the southern parts of Russia or even to the Southern hemisphere where fire seasons occur during Russias winter time. Setting up of several dozens of such lookout points in a short period of time is much more lucrative compared to the construction of stationary towers and will let to use already available forest fire video systems in a best way.
St. Petersburg Forestry Research Institute
Forest Fire Protection Department
St. Petersburg, Institutsky pr., 21
Chief Manager, Fire TV and Communication Service
Forestry Committee of Leningrad Region
St. Petersburg, Institutsky pr.,21-E
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