Wildfires
Wildfires are a growing natural
hazard in most regions of the United States, posing a threat to life and
property, particularly where native ecosystems meet developed areas.
However, because fire is a
natural (and often beneficial) process, fire suppression can lead to more severe
fires due to the buildup of vegetation, which creates more fuel.
In addition, the secondary
effects of wildfires, including erosion, landslides, introduction of invasive
species, and changes in water quality, are often more disastrous than the fire
itself.
The USGS, in conjunction with the
U.S. Forest Service and other partners, provides tools and information by
identifying wildfire risks and ways to reduce wildfire hazards, providing
real-time firefighting support, and assessing the aftermath of wildfires. The
goal is to build more resilient communities and ecosystems.
The Basic Elements of Fire
The word "fire" refers
to the natural phenomenon that occurs whenever a combustible fuel comes into
contact with oxygen at an extremely high temperature. Fire is the byproduct of a
chemical reaction in which fuel stored in a combustible fuel is converted to a
gas. A fire's flame refers to the visual indication of light that occurs once
the gas is heated, and is evidence that a fire has taken place.
The Fire Triangle
The Fire Triangle was developed
by natural scientists as a simple way of understanding the factors of fire. Each
side of the triangle represents one of the three ingredients of fire oxygen,
heat, and fuel demonstrating the interdependence of these ingredients in
creating and sustaining fire. Remove any of these three factors from the
triangle, and a fire will die.
The interaction of the three
equal sides of the fire triangle: heat, fuel and oxygen, are required for the
creation and maintenance of any fire. When there is not enough heat generated to
sustain the process, when the fuel is exhausted, removed, or isolated, or when
oxygen supply is limited, then a side of the triangle is broken and the fire is
suppressed.
Fire is Nature's Housekeeper
Since the dawn of time, fires have burned regularly, consuming vegetation,
accumulations of insects and diseases, and triggering a rebirth of forests.
Without periodic fire, plants and animals requiring nutrients and vegetation
from other parts of the cycle disappear. Fire, in places where it is a crucial
part of the ecosystem, promotes vegetative and wildlife diversity, helps
maintain wilderness and wildland areas, and eliminates the heavy fuel
accumulations which can ultimately lead to catastrophic wildfire. Many plants
have evolved adaptations that protect them as a species against the effects of
wildland fire, and some are even strengthened by it. Nearly every ecosystem in
the country has some kind of fire dependent plant or tree.
Fires in Southern California
Fueled by the powerful Santa Ana
winds that whip from the high-altitude deserts of the Great Basin toward the
Pacific Ocean, 12 large wildfires raged in California on October 23, 2007. The
fires clouded the air over the Pacific with dense plumes of smoke that stretched
across hundreds of kilometers. The immensity of the event is illustrated in the
top photo-like image, captured by the Moderate Resolution Imaging
Spectroradiometer (MODIS) on NASAs Terra satellite on October 23. The lower
image shows a close-up view of the Witch Fire, burning between Los Angeles and
San Diego. At the time the image was taken, the fire had burned 145,000 acres,
destroying hundreds of homes and commercial buildings, and threatening thousands
more, said the National Interagency Fire Center. Areas where MODIS detected a
fire are outlined in red, though the dense smoke may have masked some of the
flames from the sensors view.
As the top image shows, the Witch
Fire was not the only destructive fire burning in southern California. As of
October 23, fires stretched from the Mexican border to north of Los Angeles,
burning more than 1,300 homes and forcing more than half a million people from
their homes, reported CNN. Windy weather pushed the flames through brush and
grass dried from drought.
Although the chemical
reaction known as fire is inherently neither good nor bad, the
circumstances surrounding its ignition, its burn rate, its location, and
its intensity are.
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Prescribed
Fires are Good Fires
As one of the most
important natural agents of change, fire plays a vital role in maintaining
healthy ecosystems. Prescribed fire reintroduces the beneficial effects of
fire into an ecosystem, producing the kinds of vegetation and landscapes
we want, and reducing the hazard of catastrophic wildfire caused by
excessive fuel buildup.
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Wildfires
are Bad Fires
They
destroy wilderness, property, and lives. As more homes are built in and
around forested areas, and as more people take to our country's wildland
areas, wildfires are also on the rise. Through discarded smoking products,
sparks from equipment in operation, arced powerlines, campfires, arson,
debris burning and other careless means, wildfires are often ignited, and
its fires such as these unplanned, uncontrolled and unnecessary
that could be most easily prevented.
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Safety Tips
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Don't
park your vehicle on dry grass. |
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If
off-road vehicle use is allowed, internal combustion equipment requires a
spark arrester. |
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Know
your county's outdoor burning regulations. Unlawful trash burning is a
punishable offense. |
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At
the first sign of a wildfire, leave area immediately by established trails
or roads. Contact a Ranger as soon as possible. If escape route is
blocked, go to the nearest lake or stream. |
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Leave
campsite as natural as possible, traveling on trails and other durable
surfaces. |
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Inspect
your site upon leaving. |
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Never
take burning sticks out of a fire. |
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Never
take any type of fireworks on public lands. |
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Keep
stoves, lanterns and heaters away from combustibles. |
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Store
flammable liquid containers in a safe place. |
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Never
use stoves, lanterns and heaters inside a tent |
ONLY
YOU CAN PREVENT WILDFIRES
Credit: USGS, CDC, Smokey Bear, US Forest
Service,NASA
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