1. What are the main causes of wildfires?
Human carelessness causes the majority of forest fires. They are also known as wildfires and may be defined as any fire that burns uncontrolled in vegetative or associated flammable material. Wildfire causes are classified according to the ignition source or to the general human related activity which started the fire.
Causes include: lightning (the only non-human related cause), campfires, smoking, debris burning, incendiary/arson (legal definition of arson differs by jurisdiction), equipment use, railroad, children (12 and under) and miscellaneous (a wildfire with a definite cause that cannot be properly classified under other general causes such as fireworks or blasting fires, spontaneous combustion, power lines ...).
For more information visit http://www.nwcg.gov/pms/pubs/nfes1874/nfes1874.pdf
2. Why is lightning so dangerous?
Lightning fires are particularly dangerous due to the fact that they are not caused by humans, and thus not preventable. They can often smolder and burn undetected in remote areas for days and even weeks before becoming an active wildfire. Lightning-caused fires can destroy timber, forest products, equipment and structures.
Lightning usually occurs with rainfall and higher levels of relative humidity (amount of moisture in the air at a given temperature) thus lowering its chances of igniting fires. However, when dry lightning does occur, it is a strong ignition source. Dry lightning does occur in the Northeast, but it is quite frequent in the western states and provinces.
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3. How big do forest fires get?
A forest fire can be as small as a few feet by a few feet, that is it can be contained to a few trees, or it can be as large as hundreds of thousands of acres. How big a forest fire can get depends on many factors, including weather, topography, ignition source and type of combustible. We must keep in mind that Canada uses hectares to measure how much forest was burned, whereas the United States uses acres. A hectare is 100 metres by 100 metres, the equivalent of two football fields. A hectare is approximately equivalent to 2 acres.
4. Is it possible to predict what the next fire season will be like?
Forest fires depend greatly on meteorological conditions, and since it is nearly impossible to predict the weather more than a week in advance, the same goes for forest fires. Long-term trends in the weather such as many weeks of rain, huge amounts of snow fall or droughts can be indicators. However, weather conditions rapidly evolve thus impacting the forest fire threat.
5. How fast do fires burn?
Wildfires can either have very little forward progression, and remain contained to a single tree or they can spread very quickly. Rates of spread can reach several miles or kilometres per hour. Variables such as wind speed, topography, the weather, the type of fuel in which the fire is burning and even the time of day will impact the fire's rate of spread.
For example, coniferous trees burn 5 to 10 times faster than deciduous trees. Their resin and needles are more vulnerable than the green leaves of a deciduous tree.
For more information visit http://www.forestencyclopedia.net/p/p4/p140/p354/p448
6. How much heat comes off a fire?
The rate of heat released by a wildfire is usually calculated in KW/m. Fires can either release very little heat if they are burning deep within the ground or they can release in excess of 10 000 KW/m. Fuel type, weather and topography are factors that impact a forest fire's intensity.
For more information visit http://www.forestencyclopedia.net/p/p486
7. What about all the smoke?
The smoke from forest fires can inconvenience nearby people and even cause health problems particularly for children and the elderly. Weather conditions greatly affect the density of smoke and the distance it can travel. When winds are calm, smoke may be very dense in surrounding areas. However, if the winds are heavy, the smoke can be carried great distances. For example, in 2010, the smoke from forest fires in Quebec reached the North-eastern United States
8. When is the wildfire season in the Northeast?
As wildfires are closely related to weather, they can occur at all times of the year. If temperatures are right, fuels can dry and even burn with snow still on the ground. Generally fires can occur in the months ranging from March to November. How quickly the snow melts in the spring or how quickly it arrives in the fall will impact the length of the fire season.
Spring and fall are busy seasons for surface fires, due to the fact that there is little leaf coverage in the trees. All the dead leaves on the ground provide an efficient fuel for surface fires. The summer months are usually more conducive to lightning caused fires which can become quite large.
9. What is a "prescribed burn?"
A prescribed burn is a planned and controlled fire set by an agency. Usually, agencies use prescribed burning to reduce the build-up of fuels in forested areas.
10. Why do agencies start their own fires?
In certain cases, an agency may start a fire to combat an existing forest fire. Burning the combustible matter in a controlled way in a certain area will cause the existing fire to slow and lose intensity when it reaches the already burned portion. Prescribed burning is a tool used in wildfire management for the protection of communities. It also has ecological and wildlife benefits.
11. What is an "urban interface fire?"
The urban interface is the "area where homes meet the forest." Wildfires in this area are particularly difficult to suppress due to the flammable vegetation found near homes. This vegetation not only provides fuel for the fire to burn, but also impedes access to the structures the firefighters are trying to protect. Fires in the wildland urban interface require specialized equipment, training and personal protective equipment
12. How can I protect my house or cottage from a wildfire?
The key to protecting structures from wildfire is prevention before a wildfire occurs. In the event of a catastrophic wildfire, there is no time to clear brush and remove excessive vegetation. Only professionally trained firefighters should attempt to fight a wildfire. In general, we recommend a minimum of 30' (9.2 meters) of managed vegetation between your home and the forest. For more information, please visit http://www.firewise.org/
13. How do sprinklers work?
Sprinkler systems can be installed on houses or other valuable structures and items. They are used as a preventive measure in order to protect the house from a fire's radiant heat (heat transfer through air in any direction). The humidity they create can reduce the fire's potential intensity. The water from the sprinklers also changes the moisture level of the materials on the house, making them less likely to ignite.
14. Why should we be especially careful in the spring?
In early spring, when all the snow has melted and the surface fuels (dead leaves, branches, dried grass) are exposed due to the absence of leaf coverage in the trees, wildfires are easily ignitable. It only takes a few hours of sunlight to dry the surface fuels, thus making them very volatile. Generally a dry dead leaf will ignite much faster than a mature green leaf.
For this reason, making clearing fires in the spring, particularly if it is windy, is very risky. Spring fires spread very quickly, it is important to be vigilant and well prepared.
15. What is an open fire?
Specific definitions may differ from one agency to the next, but generally, an open fire is any fire that is not contained by a fireguard. Examples include, campfires, bonfires and clearing fires (allowance differs per agency). Likewise, any item that can easily ignite a fire is also considered an open fire. For example, fireworks or tools used for welding could ignite a forest fire in dry conditions.
Only fires completely contained by a metallic fireguard (holes should be no bigger than 1 cm or 0.5 inches), are not considered open fires. Before proceeding with an open fire, verify the regulations in your jurisdiction.
16. A ban on open fires in or near forested area – what is it?
Many agencies have regulations concerning the types of outdoor fires citizens can make. Some bans on open fires may be in place all year-long or may be implemented during critically dry periods. These regulations aim to protect the forest as well as near-by communities from wildfires. Always check with your local officials what the regulations are before making campfires, clearing fires or using fireworks.
17. Is my campfire safe?
Using an enclosed fireplace with a metallic fireguard is always preferable when making a campfire, but if are allowed to make an open campfire, please remember the following rules. Choose a cleared area, protected from the wind and close to water. Keep a constant and watchful eye on the fire and never leave it unattended. Always put your fire dead out by drowning it with lots of water. Stir the ashes, and drown again. With the back of your hand (cold trailing), check that no heat remains. For more safety tips, visit our Prevention Tips page.
18. Do I have to do anything when planning a backyard burn?
Always check with local officials what the regulations concerning open fires are in your area. Some areas may require a permit, with special instructions such as what time of day is best. When it is permitted to burn debris, always remember to properly prepare the area, choose a time of day when the wind is low, have a water supply and rake on hand, constantly monitor the fire and completely extinguish all embers before leaving the premises.
19. How are wildfires detected?
Forest fires are detected using several methods which may differ by agency. One method however, remains universal and that is the general public. Whether it be a hiker, a fisherman, or a rural homeowner, the collaboration of the public is very important.
Other detection methods include using small aircraft to patrol forests during critical periods, observation from forest fire towers, and patrols through forested areas by local, state or provincial persons. A popular myth is the use of satellites. Where satellites are used to track certain fire activity and smoke patterns, they are not generally used to detect new fire starts.
20. You see a suspicious smoke, what should you do?
It is important to alert the authorities as quickly as possible. If you have access to a telephone call your local fire fighting agency or dial 911 immediately. Even if you do not see flames, but are suspicious of a smoke please inform the authorities. The authorities will investigate further to determine if an intervention is necessary. The sooner a fire is reported the more efficient firefighters can be, perhaps greatly impacting the forest, the wildlife and the surrounding communities. Early detection may also lessen the danger to our firefighters.
21. Does a fire really sleep during the night?
While wildfires don't actually sleep, typically they do exhibit a cycle of higher activity during the day and then "rest", that is, exhibit less intense activity when the sun goes down. This burn cycle is the result of the interaction of several factors that influence fire behaviour, namely, temperature, relative humidity and fuel moisture. We call it the Fire Clock. As morning progresses into mid-day, the temperature normally rises, causing relative humidity to decrease.
In this relatively drier atmosphere, fine flashy fuels, like twigs, pine needles and dead leaves, dry out and ignite more easily. These are the fuels that carry wildfire. By the middle of the afternoon, conditions for burning are typically optimal. As the sun sets and temperatures drop, the relative humidity increases and the fuel moisture content of fine fuels increases as well. These fuels are less prone to burn, so fire intensity decreases during the night – perhaps conjuring an image of a sleeping fire.
For more information on the Fire Clock visit:http://northeastwildfire.org/documents/activities/funfacts/Fun_Fact_10_Fire_Clock.pdf
22. What were some notable recent wildfires?
1988 – The Yellowstone Fire; largest and most expensive fire in US National Park System history, 793,880 acres (3,213 sq. km), no fire fighters killed.
1994 – South Canyon Fire on Storm King Mountain, Colorado; kills 14 fire fighters.
2003 – Okanagan Mountain Park Fire, British Columbia; more than 250 square kilometres, 239 homes destroyed.
2007 – October 2007 Fires, California; a series of fires killed 9 people, burned more than half a million acres (2,000 sq km) and forced the evacuation of more than one million people.
2009 – Black Saturday brushfires, Australia; as many as 400 separate fires, 173 people killed, 2029 homes destroyed.
2013 - Yosemite National Forest/RIM Fire, Tuolomne County, California; as of October 2013, 257 171 acres burned, all but southern section of parc impacted. Videos can be seen at : http://vimeo.com/channels/rimfire
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23. What is the "Incident Command System?"
The Incident Command System (ICS) is an organizational structure used by various levels of government as well as nongovernmental organizations and the private sector. ICS is a standardized management approach that can be used for both incidents and planned events. Certain fire fighting agencies employ this organizational structure to manage wildfires.