Biology:Firebreak

A firebreak or double track (also called a fire line, fuel break, fireroad and firetrail in Australia) is a nonflammable gap in vegetation or other combustible material that acts as a barrier to slow or stop the progress of a bushfire or wildfire. A firebreak may occur naturally where there is an absence of vegetation or "fuel", such as a river, lake or canyon. Firebreaks may also be man-made, and many of these also serve as roads, such as logging roads, four-wheel drive trails, secondary roads, or highways.

Overview

A poster promoting plowing to create a fire break

File:Video explaining contingency lines during the North Complex Fire.ogv

Prevalence

Forested areas often contain vast networks of firebreaks. Some communities are also using firebreaks as part of their city planning strategy. An example is the city of Revelstoke, British Columbia, which includes firebreaks in their Community Wildfire Protection Plan.

Effectiveness

By comparing the burnt (right) and unburnt (left) sides of a dirt road in South Africa after a major veldfire (grassland fire) the effectiveness of the road in acting as a firebreak can be seen.

Depending on the environmental conditions, and the relative effectiveness of a given firebreak, firebreaks often have to be backed up with other firefighting efforts. Even then, it is still sometimes possible for fire to spread across a seemingly impenetrable divide. For example, during the Cedar Fire of 2003, strong Santa Ana winds had blown enough burning embers across a 10-lane section of Interstate 15 to ignite the vegetation on the other side. During the 1988 fires in Yellowstone National Park, hot embers managed to cross the Lewis Canyon, a natural canyon up to a mile wide and 600 feet (180 m) deep. In Australia, firebreaks are less effective against eucalyptus forest fires, since intense fires in tinder-dry eucalyptus forest spread through flying embers, which can be carried by the winds to trigger new blazes several kilometres away. In 2019, goats deployed to graze the nearby flammable vegetation and create a firebreak helped save the Ronald Reagan Presidential Library and Museum and Getty Museum from California wildfires.

Green firebreak

Green firebreaks are lines of low flammability vegetation, planted to retard fire. Among their advantages are lower cost, biodiversity and reduced erosion.

History

Due to a lack of a standardized firefighting force at the time, the Great Fire of London in 1666 instead saw the Tower of London garrison using gunpowder and fire hooks in a widespread, ad-hoc firebreaking campaign across Central London. Historians believe this to have been one of the major contributing factors to the eventual defeat of the inferno.

The world's most expensive firebreak was created when part of Van Ness Avenue in San Francisco was dynamited to stop the spread of fire resulting from the 1906 San Francisco earthquake. Firefighting after an earthquake can be especially challenging, because an earthquake can cause water mains to rupture, resulting in a complete loss of water pressure.

Firebreak in the Brendan T. Byrne State Forest in New Jersey's Pine Barrens ecoregion

See also

• Fire trail
• Controlled burn
• Defensible space (fire control)
• Fire ecology
• Firefighting
• Firewall (construction)
• Fuel ladder
• Glossary of wildfire terms
• Wildfire suppression