Wildfires

Characteristics


A wildfire is an uncontrolled burning of grasslands, brush, or woodlands.

Hot, dry summers and dry vegetation increase susceptibility to fire in the fall, a particularly dangerous time of year for wildfire. Wildfires are part of the natural management of forest ecosystems, but may also be caused by human factors.
Wildfire

Occurrence


Nationally, over 75,000 wildfires occur each year. Around 90% of forest fires are started by negligent human behavior such as smoking in wooded areas or improperly extinguishing campfires. The second most common cause for wildfire is lightning. 

Fire season in the southeastern United States runs from March through May.

Fire Spread


There are three general patterns of fire spread:
  • Crown Fires - which burn through the top layer of foliage on a tree, known as the canopy or crown fires. Crown fires, the most intense type of fire and often the most difficult to contain, need strong winds, steep slopes and a heavy fuel load to continue burning.
  • Ground Fires - which burn organic matter in the soil beneath surface litter and are sustained by glowing combustion
  • Surface Fires - which spread with a flaming front and burn leaf litter, fallen branches and other fuels located at ground level

Development Risks


The potential for a major fire hazard depends on:
  • Characteristics of the fuel
  • Climate (local weather conditions)
  • Debris burning and construction
  • Degree of public cooperation with fire prevention measures
  • Outdoor activities

Fuel Characteristics


Understanding the fuel characteristic is important because a fuel's composition, including moisture level, chemical makeup and density, determines its degree of flammability. 

Moisture level is the most important consideration. Live trees usually contain a great deal of moisture while dead logs contain very little. The moisture content and distribution of these fuels define how quickly a fire can spread and how intense or hot a fire may become. High moisture content will slow the burning process since heat from the fire must first eliminate moisture.

In addition to moisture, a fuel's chemical makeup determines how readily it will burn. Some plants, shrubs and trees contain oils or resins that promote combustion, causing them to burn more easily, quickly or intensely than those without such oils.

Soil types also must be considered because fire affects the environment above and below the surface. Soil moisture content, the amount of organic matter present and the duration of the fire determine to what extent soil will be affected by fire.

Weather Conditions


Weather conditions such as wind, temperature and humidity also contribute to fire behavior. 

Wind is one of the most important factors because it can bring a fresh supply of oxygen to the fire as well as push the fire toward a new fuel source.

Temperature of fuels is determined by the ambient temperature since fuels attain their heat by absorbing surrounding solar radiation.

Humidity, the amount of water vapor in the air, affects the moisture level of a fuel. At low humidity levels, fuels become dry and, therefore, catch fire more easily and burn more quickly than when humidity levels are high.

Damages & Dangers


Wildfires can result in economic losses as well. Wildfires can cause disruptions to:
  • Business in or near the fire areas
  • Logging and paper product companies
  • Outdoor recreational business
  • Tourism based companies 
These impacts, if persistent, can result in economic losses that result in lost jobs. State and local governments can impose fire safety regulations on home sites, new developments, and industry to help with wildfire hazards.

Communities can also adopt Firewise principles to help mitigate and reduce their risk. Hazard reduction can include land treatment measures such as:
  • Buffers
  • Fire access roads
  • Firebreaks
  • Fuel breaks
  • Fuel management
  • Safety zones
  • Water storage
Fuel management, along with prescribed burning programs and cooperative land management planning can all be utilized to help reduce fire hazards.

Wildland Urban Interface



The Wildland Urban Interface (WUI) is the area where structures and other human development meet or intermingle with undeveloped wildland, forest or vegetative fuels. 


North Carolina has more WUI acres than any other state in the country and our growth increases this acreage every year. The interface creates great challenges for fire managers as nearly every fire or its associated smoke may impact homes, roads, farms or other development.

Further, the increasing demand for outdoor recreation places more people in wildlands during holidays, weekends and vacation periods. Unfortunately, wildland residents and visitors are rarely educated or prepared for wildfire events that can sweep through the brush and timber and destroy property within minutes.

Wildfire Safety

  1. Basic Safety
  2. Prepare Your Home
  3. After a Fire

Basic Safety Tips:


  • If you see a wildfire and haven't received evacuation orders yet, call 9-1-1. Don't assume that someone else has already called.
  • If ordered to evacuate during a wildfire, do it immediately- make sure and tell someone where you are going and when you have arrived.
  • Many communities have text or email alerting systems for emergency notifications.To find out what alerts are available in your area, search the Internet with your town, city, or county name and the word “alerts.”
  • If you or someone you are with has been burned, call 9-1-1 or seek help immediately; cool and cover burns to reduce chance of further injury or infection.

Additional Resources



Want to learn more about wildfires and how to prepare yourself? Visit these sites for more information: