00:00Forest fires spread due to a combination of wind, vegetation and hilly terrain. Wind fans
00:15the flames, affects the direction of the fire and transports embers and burning particles
00:21which allow the flames to jump over roads or fire breaks. Vegetation fuels fire. The
00:27drier the forest, the faster the fire spreads, travelling at up to 5km an hour. The more
00:33bushy the forest, the faster the fire spreads, particularly if the undergrowth isn't regularly
00:38cleared. A carpet of dry leaves is perfect fuel. In hilly areas, upward slopes tend to
00:45accelerate the fire, while it decelerates downhill. In high risk areas, aerial spotters
00:51carry out surveillance all day long. As soon as a fire is detected, trackers discharge
00:58water mixed with a flame retardant, a fireproof salt which helps prevent vegetation from burning.
01:05If the fire develops, Canadair planes carrying greater volumes of water go back and forth
01:10over the zone, dousing the flames with their 6,000 litre cargo. On the ground, firefighters
01:17are dispatched, coordinated by a command post to ensure they're not injured by the
01:21tonnes of water being dropped from the air. Two strategies are possible. Offensive, whereby
01:26firefighters get as close as possible to the blaze surrounding it from all sides. Or there
01:32is the defensive strategy, fire crews wait for the fire to reach them, while protecting
01:37vulnerable areas by establishing a line of vehicles to intervene by dousing the flames.
01:43In certain cases in uninhabited areas of forest, forest rangers can light tactical
01:49fires under the supervision of the fire brigade, creating scrubbery zones which act as fire
01:53breaks and can stop the fire in its tracks. This technique tends to be used in Canada
01:58and the United States.
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