Many parts of the United States, especially the western part, have been hit by devastating wildfires this year.
At press conferences and warnings to residents, firefighters tout figures of thousands of acres burned, “red flag conditions” encouraging “extreme fire behavior” and increasing percentage of “complexes” You may talk about what is holding you back from your efforts. It means “to contain”.
Here’s a guide to help you understand some of the terms officials use when discussing wildfires.
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If fire officials report a fire 30% contained, that means 30% of the flame’s boundary is surrounded by a barrier, such as a river, stream, interstate, or already charred area, and the fire is not likely to start. There is no more vegetation left. These containment lines are also 10- to 12-foot wide trenches that crews dig (sometimes with bulldozers) along the edge of the fire to prevent the fire from spreading.
Just because authorities say a fire is 100% contained doesn’t mean it’s extinguished. This just means that the firefighters are completely surrounded. It may still burn for weeks or months. Once the fire is declared “controlled,” that’s it.
fire alarm
A red flag warning is the highest warning issued by the National Weather Service for conditions that could lead to extreme fires in the next 24 hours. Weather forecasters issue such warnings when high temperatures (above 75 degrees), very low humidity (less than 25%), and high winds (at least 15 miles per hour) combine to increase the risk of fire.
If you live in an area with red flag warnings, you should ensure that:
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Remove dead weeds and vegetation around your home.
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Empty the roof and gutters and remove dead leaves and other debris.
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Move flammable household items outside, such as brooms and lawn furniture cushions.
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Do not use the mower on dry land.
extreme fire behavior
Extensive fire behavior generally includes some or all of the following:
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high diffusivity
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Flames that grow from tree branches, leaves, and shrubs without the help of fire on the ground.
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A vortex of heat and gas generated from a fire on the ground, the presence of a fire vortex that carries debris, flames, and smoke into the air. They range in diameter from less than 1 foot to over 500 feet. The largest resembles the strength of a small tornado.
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The presence of convective columns that extend vertically rather than horizontally, sending gases, smoke, fly ash, particulates, and other debris produced by a fire directly into the air
compound fire
When two or more wildfires burn close together in the same area, they are often called a “complex” and are attacked by firefighters under a unified command.
In the summer of 2020, air raid sieges set off about 40 fires in three national forests in northwest California. all of them combined August Complex fire. In total he burned more than a million acres, hence the new term “Gigafire”.
burnt acres
When you hear about the 100,000 acre fire, it describes the total area burned, not what was actively burning at the time.
But as Ernesto Alvarado, a professor of wildfire sciences at the University of Washington, explained, “There is no way to map 100,000 acres of land with people.”
Instead, authorities are turning to aircraft with thermal imaging cameras and weather satellites that can take images of the fire zone every five minutes. Firefighters can create real-time maps from these data. This map is complemented by ground information to map large fires.
fuel
In a wildfire, fuel is anything that burns. It can be trees, shrubs, grass, fallen branches, leaves, pine needles, almost anything in the entire landscape. All of these vegetation act as flashpoints that increase the risk of hotter, bigger, longer and faster wildfires.
flashback or burnout
Both flashbacks and burnouts are fires set along the ground to combat wildfires. They share the goal of clearing out all vegetation, starving wildfires, and creating a fuel-free barrier.
Backfire is an indirect method of attack. Fire along a ribbon of land near a wildfire to remove all fuel and attempt to slow or change the spread of the wildfire.
Burnout is more direct because it builds near the edge of the fire and consumes unburned fuel. Burnout operations are often used when firefighters need to direct wildfires around sensitive areas such as towns, power lines and even hills.
prescribed combustion
A prescribed burn is an intentional fire. Authorities are able to set their own fires very carefully under relatively safe weather conditions that are likely to help keep planned fires under control. A given burn must meet certain criteria, such as limiting fuel in raging wildfires or making an area less susceptible to future fires.
A written plan must consider economic, environmental, geographic, legal, public health and safety factors. National Environmental Policy ActIt also requires Environmental Protection Agency approval. This method may be chosen if the benefits outweigh the risk of unplanned and uncontrolled wildfires.
Wildfire types and levels
There are ground fires, crown fires, and ground fires. Surface fires start in plant roots and other organic matter just below the soil surface. These fires can develop into surface fires, burning dead or dry vegetation on or above the ground. Crown fires burn the tops of trees and, fanned by the wind, can be much more dangerous and move faster than surface fires.
The National Fire Hazard Rating System have 5 levels Danger: Low, Medium, High, Very High, Extreme. These are based on fuel, weather forecast, terrain, and how well prepared authorities are for potential fire problems in a particular area that day or the next.