Wildfire

Nature's Hottest Fury

GE 404 Class Project

Class Instructor, Dr. William Rose



Hello and welcome to Wildfire, a research project I worked on in conjunction with Dr. William Rose for GE 404, Natural Hazards Mitigation. The purpose of this page is to create an awareness toward wildfires; their origins and efforts to control or prevent them within the United States, and what agencies are doing to aid homeowners that build in fire prone areas.

My hope is that not only homeowners, but firefighters and agencies alike will find this page useful and informitive. Each year, wildfires consume 5% of the Earth's surface. It is essential that homeowners and fire agencies be aware of the latest technologies and improvements in wildfire suppression and mitigation.


Shortcut to topics



What is wildfire?

In a strict sense, the term 'wildfire' can be broken into two words. The meaning of wild is "something that is not easily restrained; uncontrollable" while fire is "a destructive burning". With this, the term wildfire then can mean "a highly destructive, uncontrollable fire". During a firestorm, a wildfire produces the same amount of energy in 10 minutes as a nuclear bomb!

In a chemists sense, a fire is the rapid combination of oxygen, carbon, hydrogen and other organic material to produce flame, heat and light. In effect, a fire is nothing more than the photosynthesis process backwards; the fire equation is identical to photosynthesis except it runs in the opposite direction. The solar energy stored in plants during their growth is returned to the atmosphere during a fire.

However, firefighters describe wildfires as the devil himself; a snarling, breathing monster capable of destroying anything in its path. In either case, wildfires are one of natures most costly natural hazards and can be as unpredictable as tomorrows weather.


History

Wildfires are not new, they have been with us since the beginning of time. Tree ring data has shown that huge areas of Yellowstone National Park have burned in the past. On October 8th, 1871, wildfires incinerated farms in 7 states and destroyed the cities of Peshtigo, Wisconsin and Chicago, Illinois. In 1910, fires scared over 5 million acres of the West. Undoubtably the last large meteor impact on Earth caused a worldwide fire event. Even today, wildfires like the 1988 Yellowstone, the 1994 Storm King Mountain or the 1991 Oakland/Berkeley Hills event clearly etch in our mind the fact that wildfires are here to stay.


Causes

When it comes to why wildfires occur it comes down to two main causes, natural or man-made. Weather plays an important role in the events leading to the fire as well as during the fire. A hot dry weather pattern for prolonged periods dry out the grasses and leaves needed to fuel a wildfire. Combine this factor with a dry thunderstorm producing lightning and you have the formula for a major fire. Strong winds not only from weather related causes but from the fire itself can push a fire out of control and beyond the capabilities of the firefighter.

Lightning strikes the Earth over 100,000 times a day. Of these, 10-20% cause a fire. It's no wonder that lightning is the biggest cause of naturally occurring wildfires. In the United States, lightning starts a wildfire around 8% of the time. Even though this sounds like a small number, consider the amount of thunderstorms that occur in the U.S. in a single summer. Most fires are concentrated in the Western states, especially during an El-nino year. Fire agencies across the West are already planning for this years anticipated increase in fires. Another cause of wildfires, though very rare, is the buildup of grass, leaves and twigs in a pile. This accumulation of dead matter can create heat, enough in some instances to spontaniously combust and ignite the surrounding area and combined with the right weather situation can cause problems.

The second cause is one that can be prevented in most cases but can never be predicted. Man-made causes such as arson or plain carelessness by individuals is the biggest cause of wildfires in the U.S. Just a simple, peaceful campfire in a campground, not properly tended to, can lead to a major wildfire especially in fire prone areas. Arson, whether intentional or accidental, is a major problem in the Western states, especially California. The fires that broke out on October 27, 1993 in southern California were, however, started when strong Santa Ana winds downed powerlines which created sparks and led to an uncontrollable wildfire that burned for 9 days.


Types

When dealing with the different kinds of wildfire that occurs, firefighters refer to them as a code or types of fire. Surface fires are just that; fires that burn in grass, shrubs and plant matter such as leaves and fallen bark. These travel at high but are easy to control, mainly because there are no convection currents to deal with. Crown fires come in two types. A dependant crown fire happens when heat and embers from surface fires ignite the tops of adjacent trees. These tend to occur when winds are low and trees are spaced far apart. Running crown fires are a firefighters worst nightmare. They burn extremely hot, travel rapidly and can change direction quickly. Perhaps the most dangerous aspect of a running crown fire are the convection currents, producing massive firestorms and tornados that can send embers well ahead of the main fire front, creating spot fires that in turn can start new fires in another direction. The last kind is the ground fire. They burn unnoticibly underground in bogs and forests. Luckly, their spread is slow, but they may pop out of the ground anywhere and cause damage in unlikely areas. Knowing the different kinds of wildfire helps in not only suppression, but also mitigation and planning for the next fire that will happen. It is important to fully understand the nature of the fire before one can properly mitigate it.





Suppression

A major part of wildfire mitigation today is suppression. There is a growing coalition of firefighters and agencies that believe fire can be a good thing. For years, children and adults alike were bombarded with the message, "Only you can prevent forest fires", from everyone's favorite naturalist Smokey the Bear. This is still great advice for the general public, but for fire agencies, a new slogin is appearing, 'Smokey is dead'. Two methods being experimented with is control burns and backfires, or backburns.

Control burns are not new; they have been used by man for hunting purposes since man discovered fire. The Aboriginal people of Australia have used used control burns to clear brushy areas of the outback for hunting and transportation. Fire agencies in the U.S. started using control burns in the 1960's with little success, mainly because they still hadn't fully understood wildfire patterns and behavior and also many burns were not kept under control and caused more damage than good. These days, control burns have become a useful tool in preventing wildfire in certain areas.

For most of this century, people have been trying to stamp out forest fires. And we've done a pretty god job. The result has been a long buildup of dead and live wood in the forests that, when ignited, burn with a fury. What a control burn essentially does is strip a forest of dead leaves, grass and brush; the fuel of a wildfire. Without these fuels a wildfire has no chance of burning. Unfortunitly, the best time to initiate a control burn is during a hot, dry spell; the same time as peak wildfire conditions, and although control burns do sometimes slip their leashes, fire agencies agree the pros outweigh the cons.

Another method of suppression is the backfire or backburn. Backfires are a relatively new process where during a wildfire, smaller fires are set ahead of the main fire to clear the area of all dead matter. The process is similar to a control burn; get rid of all usable fuel for the wildfire to feed upon. Backfires were first seen a skeptical method of bringing a raging wildfire under control. However, the success of backburns at Yellowstone National Park in 1988, which burned over 1/3 of the park, proved that this new idea in wildfire suppression is here to stay.


How homeowners can help

Homeowners that build in fire prone areas can greatly reduce the risk of losing their home and other buildings in a wildfire by taking simple, preventive measures. Removing dense underbrush by trimming small trees, clearing brush and other dense fuels that burn rapidly. Cutting tall grass near any structures will ensure that the most rapidly burning fine fuels will not be a problem. Eliminate the accumulation of leaves and twigs by raking them away early in the spring. Remove branches of large trees to a height of 6-10 feet above the ground. This will prevent surface fires from spreading to the tops of these trees. Lastly, remove all cut grass and underbrush, pruned branches, leaves, twigs and other refuse in a reccommended manner.

Perhaps the best prevention of losing your house in a wildfire is to not build in a prone area. Many people when building their dream home or retirement home never think of the possibly dangerous situation that could arrise if a fire was to sweep through that area. This was so evident in the Stephan Bridge Road fire. The residents that lost their homes never thought it could happen to them. Combine this with the fact that these same people never cleared the area around their house of dead grass and brush, which in turn fed the fire. The residents that read the publicationsput out by local fire agencies and followed them, in most cases, saved their homes from the fire. One of these publications, Wildfire, are you prepared for its deadly force?, put out by the Michigan Interagency Wildfire Prevention Group, provides a checklist for residents to use to answer this all-important question. Another publication is titled, Wildfire: Are you prepared?. This publication, put out by the Red Cross, also describes ways to prevent your home from being destroyed by fire. It also covers what to do if you are required to evacuate your house and what to include in a disaster supplies kit.


The future of wildfires

Fire is a natural force that has been used for thousands of years for purposes both good and bad. It is important to note that even though fire has a reputation for being a destructive force, it can also be used, in a controlled manner, to benefit man. However, most research on wildfires are centered around ways to suppress and mitigate them. There are many ways to this. One is to use control and backburns to eliminate buildups of potential fuels such as dead grass, leaves and brush. Fires threats are the greatest where there is a huge contrast in seasons. A wet season leads to prolific plant growth while dry conditions kill and dehydrate the plants making them suceptable to ignition. Add in some stong winds and a dry thunderstorm and you have the ingrediants for a major wildfire.

Buildings can be made to withstand fire, or at least be fire resistant. Older structures can be made safer by clearing vegetation and moving woodpiles away from them. Avoiding wood siding, wood shingles, overhanging decks and balconies made of wood can gretaly reduce the risk of a structure catching fire. Double-pane glass windows and doors as well as spark arresters on chimneys can also help. Of course, the best advice one can have before building a dream home is to check and see if the area your building in is a fire prone area, or has had a history of wildfires. If it has, don't build there!

Fires cannot be prevented, only deffered. We pay a high price for wildfire suppression; insurance costs, human lives, rebuilding and firefighters safety all contribute to this high price. Allowing natural fires to burn helps prevent buildups of extensive debris that can fuel a firestorm during heavy winds. Even with todays technology and advancements in wildfire research, large firestorms like the ones that burnt in Yellowstone and Berkeley Hills, California are essentially unstoppable. The choice is up to firefighters, fire agencies and the public; lots of little fires or a few monstrous firestorms.


Some links to related sites

Here is a link to a wildfire that happened on May 8, 1990 east of Grayling Michigan.
There are some really interesting pictures of wildfires in this page, showing their strange habits and burn patterns.
Line of fire is a page with lots of information and an interactive wildfire simulation.
Firewise is a great place to learn about wildfire supression for homeowners.
United States Fire Administration
USFA Kids Homepage is a page devoted to fire safety for kids.
USDA Forest Service
National Fire Protection Association
United States Fire Forcast map
Woods on fire provides a look at the advantages/disadvantages of fire suppression.


GE 404 Natural Hazards Mitigation homepage


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Last updated ======> February 16, 1998


References found here.