DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 9-10/1999 str. 58 <-- 58 --> PDF |
T. Dimitrov: ŠUMSKI POŽARI U HRVATSKOJ POVOD ZA RAZMIŠLJANJE Šumarski list br. 9-10, CXXIII(1999), 461-468 Na slikama su prikazana dva praktična primjera upociju o jačini čelne vatrene fronte od 1 685 kW/m, a u rabe FBP sustava kod eksperimentalnih šumskih požara drugom (slika 3) o jačini čelne fronte od 17 777 kW/m. najednom lokalitetu s istim tipom goriva (crna smreka-Za uspjelo suzbijanje tih požara potpuno su različite lišaj), ali s različitim ulaznim meteorološkim elementi potrebe u ljudstvu i materijalno-tehničkim sredstvima. ma. U prvom slučaju (slika 2) FBP sustav daje informa Experimental Fire: L4 Dale: July 6 Photo: G.P. Delisle Fire Weather Observations F HI System Fuel Moisture Codes Description of Fire Behavior: Dry-bulb temperature 21.5°C Fine Fuel Moisture Code (FFMC) 90.1 Fire spread more or less continuous Relative humidity 36% Duff Moisture Code (DMC) 55 across the plot area. Sporadic torching 10-m open wind 14.5 km/ h Drought Code (DC) 247 experienced at favorable locations. Days since rain 3 Smouldering black spruce needles and bark flakes were carried up to FWI System Fire Behavior Indexes Fire Behavior Characteristics 15 m ahead of the flaming trees. Downed-dead woody fuels served to Initial Spread Index (ISI) 9.1 | lead fire rate of spread 3.7 m/min reinforce the spread rate. Buildup Index (BUI) 71 Fuel consumption 1.53 kg/nv Fire Weather Index (FWI) 25 FrontalTire intensity 1685 kW/ m Type of the Fire: Intermittent crown fire Slika 2: Eksperimentalni požar L4, s jačinom čelne vatrene fronte od 1 685 kW/m. Experimental Fire: L5 Date: July 7 Photo: B.D. Lavvson Fire Weather Observations FWI System Fnet Moisture Codes Description of Fire Behavior: Dry-bulb temperature 27.5°C Fine Fuel Moisture Code (FFMC) 92.0 Initially, intense radiant heat experiRelative humidity 3 I % Duff Moisture Code (DMC) 59 enced up to 30 m downwind of tor10- m open wind 28.0 km/h Drought Code (DC) 256 ching black spruce clumps. Spot fires Days since rain 4 developed a further 20 m away. As a result, fire accelerated very quickly, involving many trees together, with FWI System Fire Behavior Indexes Fire Behavior Characteristics flames about 15-20 m high. Initial Spread Index (ISI) 23.5 Head fire rate of spread 33.3 m/min Buildup Index (BUI) 75 Fuel consumption 1.81 kg/m2 Fire Weather Index (FWI) 48 Frontal Are intensity 17 777 kW/m Type of Fire: Fully developed crown fire Slika 3: Eksperimentalni požar L5, s jačinom čelne vatrene fronte od 17 777 kW/m. |