00:00 Forest fires spread due to a combination of wind, vegetation and hilly terrain.
00:14 Wind fans the flames, affects the direction of the fire and transports embers and burning
00:20 particles which allow the flames to jump over roads or fire breaks.
00:25 Vegetation fuels fire, the drier the forest the faster the fire spreads, travelling at
00:31 up to 5km/h. The more bushy the forest the faster the fire spreads, particularly if the
00:37 undergrowth isn't regularly cleared. A carpet of dry leaves is perfect fuel.
00:42 In hilly areas, upward slopes tend to accelerate the fire while it decelerates downhill.
00:48 In high risk areas, aerial spotters carry out surveillance all day long.
00:54 As soon as a fire is detected, trackers discharge water mixed with a flame retardant, a fireproof
01:01 salt which helps prevent vegetation from burning.
01:05 If the fire develops, Canadair planes carrying greater volumes of water go back and forth
01:10 over the zone, dousing the flames with their 6,000 litre cargo.
01:15 On the ground, firefighters are dispatched, coordinated by a command post to ensure they're
01:20 not injured by the tonnes of water being dropped from the air.
01:24 Two strategies are possible, offensive whereby firefighters get as close as possible to the
01:29 blaze surrounding it from all sides. Or there is the defensive strategy, fire crews wait
01:35 for the fire to reach them, while protecting vulnerable areas by establishing a line of
01:39 vehicles to intervene by dousing the flames.
01:43 In certain cases in uninhabited areas of forest, forest rangers can light tactical fires under
01:49 the supervision of the fire brigade, creating scrub-free zones which act as fire breaks
01:54 and can stop the fire in its tracks.
01:56 This technique tends to be used in Canada and the United States.
02:00 [no dialogue]
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