Thousands of wildfires ignite in the United States every year, and each one requires firefighters to make quick decisions, often in difficult conditions such as high winds and lightning strikes.
Crews and managers need to decide when to bring planes in, the best time of day to fight the flames, whether to evacuate residents, and whether to put out certain fires at all.
In the west, where many of the country’s largest fires are recorded, they are doing all of this against a backdrop of ongoing drought and other climate change-induced conditions that have made forest fires even more devastating. Other challenges include a century of knee-jerk forest fire fighting and overgrown forests, experts say, and communities that have crept into fire-prone areas.
Russ Lane, Washington State Department of Natural Resources Fire Department chief, explains how some key fire fighting decisions are made.
Why do firefighters keep some forest fires burning?
Sometimes fires fit a useful land management goal, such as if they burn in a wilderness area or a national park.
Fires are part of the natural forest cycle, and “sometimes that’s the right approach,” said Lane, who is in his 35th season as a firefighter and spent much of it in western Oregon. He joined the Washington Natural Resources Agency in 2019.
Also, forest fires sometimes burn in areas where it is unsafe to place firefighters.
When are fire fighting aircraft used?
Airplanes or helicopters are deployed when wildfire is too intense to send ground forces or when airplanes are the best way to provide water or inhibitors, Lane said.
“You want to start a fire quickly so it stays small,” Lane said.
The aim is to prevent them from breaking out into mega fires. Cal Fire, the California Fire Department, keeps an average of 95% of fires on 4 acres or less.
But Lane said planes alone are usually not enough to put out a fire. “It takes boots on the floor.”
Aircraft can also experience numerous visual impairments when attempting to create water droplets in wildfire.
How has technology helped firefighters?
One innovation in early detection is replacing human-occupied fire towers in remote areas with cameras, many of them in high definition and equipped with artificial intelligence to detect a plume of smoke from the morning mist. There are 800 such cameras scattered across California, Nevada, and Oregon.
Fire department managers also routinely summon military drones to fly over fires at night and use thermal imaging to map their boundaries and hot spots. With the help of satellite images, they can show the course of smoke and ash.
Is there a time of day that is best to fight a fire?
In general, the heat of a summer day is not the best time to fight forest fires.
“We’re pretty successful in the morning, late at night, or overnight,” Lane said.
Are some landscapes more difficult for firefighters?
Dry flashes of lightning bring dozens of fires to the landscape, Lane said, and weather is a major factor in their spread.
Forest fires in grassland tend to grow faster and are more prone to spreading in high winds, Lane said. Fires in forest areas do not grow as quickly, but they are more difficult to extinguish.
“With grass, a little rain and it goes out,” Lane said.
How are houses saved when fire is near?
Lane said the building materials used on a home and the nearby vegetation are important factors in determining whether a home can be saved if a fire approaches.
Houses with wooden roofs and lots of combustible vegetation are the hardest to save. Typically, a fire team sprays water around a house to protect it.
Sometimes they burn out the vegetation around a house to starve out an approaching wildfire. If the homeowner holds the brush far from a house before a fire, it will be of great help, Lane said.
How are fires named?
Usually a fire is reported by the first firefighter unit at the scene. Most often, the name reflects a nearby geographic feature, e.g. B. a stream or a valley.
California’s giant Dixie Fire, for example, was named after the street it began on July 14th.
Why do firefighters spend time digging pipes?
“Every fire must be surrounded by a dirt road,” Lane said. “That’s to separate the fuel from the fire.”
Firefighters can also get help if the flames are burning toward a river, rocky area, or road. “Separating the fuel from the fire is what stops them,” he said.
Who runs the fire brigade?
Forest fires receive one of five ratings, with type 5 being the least dangerous and type 1 being the most dangerous. More than 95% of all fires are smaller type 4 or 5 wildfires and are quickly put out by local firefighters.
Larger fires, like those the Washington State Department of Natural Resources is responding to, will be assigned to an incident commander, said agency spokeswoman Janet Pearce.
The commander creates a series of objectives that guide the command and general staff. An operational area manager then works out the strategy for operational fire fighting.
When will immediate evacuations be ordered?
Emergency managers consider fire behavior, forecast weather, and the time it will take to evacuate when making the decision to order people to leave, Lane said.
They also take into account the availability of shelter and the potential for damage or loss of life.
Occasionally the order is given to make “lodging on the spot”. This usually happens when either there is no time to escape an oncoming fire or it would be more dangerous to evacuate than stay in place, he said.