SPOKANE – Thousands of forest fires ignite in the U.S. 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 in planes, 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 have occurred, it is against a backdrop of ongoing drought and other climate change-induced conditions that have made forest fires even more devastating.
Russ Lane, chief fire officer, Washington State Department of Natural Resources, explains how some key firefighting decisions are made:
- WHY DO FIRE MANAGERS LET SOME WILDFIRES BURN?
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 a firefighter in his 35th season and has 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 DO FIRE MANAGERS USE AIRCRAFT?
Airplanes or helicopters are deployed when wildfire burns 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 quick 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 percent of fires on 10 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 DOES TECHNOLOGY HELP?
An 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 call in 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.
- WHAT TIME OF THE DAY IS THE BEST TIME OF DAY TO ATTACK A BLAZE?
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 WILDFIRES DIFFICULT TO FIGHT IN WOOD OR GRASSLAND?
Dry flashes of lightning bring dozens of fires to the countryside, 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 TO SAVE HOUSES WHEN THE FIRE ARE 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 is approaching.
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.
- WHEN DO YOU ORDER RESIDENTS TO EVACUATE IMMEDIATELY?
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.