Project no. Fp6-018505 Project Acronym fire paradox

4.3.2Fire detection systems

Fire observation towers are facilities that differ as regards their construction, permitting a direct or indirect observation of the forests and give the alarm when detecting a fire. From time to time, other substitute facilities are used for observation, such as triangulation towers, water towers or church towers.

All fire observation posts should be located in places that would ensure optimum capability of observation of an area as large as possible; the observed area is determined by so-called observation (visibility) radius. It is assumed that in a flat area, it amounts from 10 to 15 km; it is a very important factor, which must be taken into account during the design of the tower network. In industrial areas, air transparency should be taken into account and observation radius should be decreased. This also applies to areas with varied relief.

Figure 12 - lookout tower with tv camera

Observation posts should be higher than treetops by a few meters and located, if possible, on natural hills or ridges. The height of observation posts can vary between 20 and 30 meters with a maximum of 50 m. At the design phase of a ground observation network (determination of the number of observation posts), the following criteria are taken into account:

• 
  in forest divisions and national parks of the first fire hazard category, each forest stand should be observed from 2 observation posts,
  
• 
  in forest divisions and national parks of the second fire hazard category, each forest stand should be observed from at least 1 observation post,
  
• 
  in forest divisions and national parks of the third fire hazard category, the forest may be observed as necessary,
  
• 
  minimum size of the protected complex or area, for which permanent observation posts should be designed, for the first fire hazard category amounts to 1000 ha, whereas for the second fire hazard category it is 2000 ha.
  

Observation posts are equipped with:

• 
  equipment permitting fire detection and identification of the place and time of fire,
  
• 
  communications equipment,
  
• 
  report book about detected fires and their notification,
  
• 
  procedure for observers, describing what to do if a fire is detected and describing obligations during observation.
  

In Figure 13, the location of observation posts in the Polish territory is depicted. Table 5 presents the number of observation posts in individual regional directorates of the State Forests per 10,000 ha of forests. The highest number of observation posts is in the RDSF in Zielona Góra (67), Katowice (65) and Szczecin (56), classified to the highest, first forest fire hazard category and the lowest number is in the RDSF in Kraków (5) and Krosno (14), consisting, in a significant part, of upland areas and highlands, which are classified as the lowest, third fire hazard category.

Figure 13 - Distribution of fire observations points in Poland

The average density of the number of observation posts per 10,000 ha of forest area in Poland is 0.9. The highest density of observation posts is in the RDSF in Warszawa (2.1), Zielona Góra (1.59), Radom (1.39) and Toruń (1.24). OP density coefficient is significantly below the national average in the RDSFs in Kraków (0.30), Krosno (0.35), Olsztyn (0.52) and Białystok (0.65).

The observation system consisting of fire observation posts and air patrols is supplemented by ground patrols equipped with means of transport. Patrolling should be organised by forest divisions and national parks. They decide when to act, routes and areas to patrol. It particularly applies to areas of high fire hazard, where tourist traffic is concentrated, along busy transport routes and in places where no other types of observation are provided. Ground patrols are introduced at the third forest fire hazard degree. The patrols should include, if possible, uniformed forest and park guards. Each team should be equipped with:

• 
  portable fire-fighting equipment,
  
• 
  report book,
  
• 
  communications equipment,
  
• 
  alerting system specification,
  
• 
  map of the patrolled area.
  

Figure 14 - patrolling motor-cycle from 1965

Patrol’s responsibility includes careful watching over fire safety, especially:

• 
  controlling the condition of all firefighting equipment, information boards, etc.,
  
• 
  paying attention to adherence to fire-protection regulations by visitors in the forest,
  
• 
  control of observance of fire safety rules in all cases involving the use of fire,
  
• 
  suppressing detected forest fires,
  
• 
  Immediate information about forest fires, report all observations connected with fire protection.
  

Figure 15 - patrolling vehicle with extinguish set

If a fire is detected, the fire patrol is obliged to start suppressing it immediately. If they are not able to suppress the fire, the patrol must notify the alarm post.

People visiting the forest know that it is controlled by its administrator, which results in higher discipline and necessity to adhere to regulations governing use of forests.

Table 6 presents the number of patrols conducted in the territory of the State Forests in the period 2002-2006. In total, the forests were patrolled 14,049 times in that period. The forest areas patrolled more often were the RDSF in Gdańsk (2812), Lublin (2441) and Olsztyn (2199). Poznań was the area where the patrol was least often (57 times).

Table 6 - Number of ground patrols by RDSF in the period 2002-2006

c) Aerial patrolling and detection

In Poland, patrolling of forests by planes to detect fires dates back to the seventies, but practical use of this method for the economic scale was employed by the end of the eighties. However, for this effectiveness to be ensured, route patrolling time should not exceed 45 minutes. In such situations, it is possible for the plane, even if its location is very unfavorable, to double back and detect fire in the initial phase of its propagation.

The number of aircraft used for patrolling in the State Forests in the period 2002-2006 is described in Table 7 and location of forest air bases is depicted in Figure 16.

Figure 16 - Distribution of forest airplane bases in Poland

Ten planes (12 at most) carried out the aerial patrol. There are 31 permanent routes; the average route patrolling time was 2.5 hours. There was no aerial observation in five RDSFs (Gdańsk, Kraków, Lublin, Łódź and Szczecinek).

Figure 17 - Field forest air base

Due to the high cost for aerial observation, only light aircrafts are used, but in spite of that, aerial patrolling has been used less and less often during the last few years. The use of this detection method occurs only when fire hazard is high and over areas where other types of observation are not used. Aerial patrolling should be treated as a supplement of the ground observation system.