Fires in southern California are a part of the ecosystem. They have been here since there was vegetation to be burned. In the early 1900’s the government made the policy that fires would be suppressed, as they created hazard to people and property, causing direct damage from the fire, but also from landslides afterward (Minnich 599). Now, there are more people than ever in the Southern California area. Because of this, more and more wildland areas are being encroached upon in order to accommodate the growing population. Another reason for wildland encroachment is that the wild areas are often the places with the best views, such as in La Canada or Malibu, and thus these places are very desirable. Although these places are sought after and people depend on the public services such as firefighters to defend their property, fire is an entity without respect for boundaries set by these growing communities. The recent Station fire devestated much of the Angeles National forest, and the subsequent landslides caused millions in damage to homes around the foothills of the San Gabriel Mountains. Now, with GIS technology, we can find that much of the damage roots from a 100 year old policy of complete suppression; meaning that we brought the destruction upon ourselves.
This mix of property and wildland forest fires has become known as the wild land-urban interface, and it has differing definitions, but here are two:
“the Urban Wildland Interface community exists where humans and their development meet or
intermix with wildland fuel. (This definition is found in the Federal Register/Vol. 66, No. 3/Thursday, January 4, 2001/Notices; and “Fire in the West, The Wildland/Urban Interface Fire Problem”, which is the “A Report for the Western States Fire Managers”, September 18, 2000.)” (qtd in http://www.idl.idaho.gov/nat_fire_plan/county_wui_plans/lemhi/_2006/definition_5.pdf).
And: “the line, area, or zone where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuel. (This definition is found in the NWCG Glossary and the 10-Year Comprehensive Strategy Implementation Plan.)”
The Interagency Fire Chiefs Wildland fire Policy Committee has established that the current policy for wildland urban interface is full suppression as stated in their report :
Aggressive action must be taken to keep unwanted wildland fires from spreading to adjacent jurisdictions during initial attack. The need for aggressive action must be revisited cooperatively during extended attack and should be commensurate with values at risk, while looking at consequences and recognition of statutory responsibilities. (IAFC Wildland fire Policy Committee http://www.iafc.org/displaycommon.cfm?an=1&subarticlenbr=151)
This policy is one that most agree with, and is very reasonable, even intuitive, but the long term effects of this policy may be much worse than we intend or even expect. One example is seen in incidents such as the station fire.
In A Paper Called : Fire Behavior In Southern California Chapparal Before Fire Control: The Mount Wilson Burns at the Turn of the Century, Richard A. Minnich explains how fire behavior in Southern California was characterized before it was suppressed by early residents: “Although these burns persisted for two to three months during summer drought, their ultimate sizes were relatively small. Chaparral in southern California watersheds before 1900 was described as having been fragmented by previous burns. Such patchy stand structure can develop from frequent anthropogenic ignitions because the growth of fires is constrained by previous burns; fire size is inversely related to ignition rates.” (Minnich, abstract). The lack of fire suppression allowed the fires to burn in a patchy pattern in which no large fires could wipe out the entire forest. The fires were frequent but small. This regime was at an equilibrium with itself, which created the best circumstances for the ecology of the area. With the frequent small fires, any subsequent landslides caused by the loss of vegetation were minor, as the burn area was relatively small, or did not completely eradicate all vegetation. Minnich says in his paper: “The extinguishing of small fires, smoulders, and secondary ignitions has a major impact upon future ignitions, fire frequency, (fire site interval), fire size, and stand structure.” Only when residents instituted the policy of 100% fire suppression did the equilibrium fall out of balance. When this equilibrium has been put out of balance long enough for heavy vegetation or ‘fuel’ buildup over large continuous areas, incidents like the station fire are the result.
Now the United States Forest Service has identified an area in which they deem to be the Wildland Urban Interface, or the areas in which the most suppression takes place as deemed necessary and put into policy. Other Forest service studies have identified areas which have fallen out of the historic fire equilibrium, or what is known as the regime of the area. With data taken from Forest Service sources we can map the two areas and see that in areas of Wildland Urban Interface, the forest is most distorted from its historic regime. The red areas outline the center of the WUI to the east of the station fire, and even the areas that are not deemed WUI, but are surrounded by it, are adversely affected as seen by the Station fires encroachment into these areas. Putting the station fire boundaries and progression on this map shows us that the station fire is entirely within areas that are moderately outside of the areas historic fire regime. We can also see that at the northeast corner of the station fire the suppression tactics in the wildland urban interface area were successful, which could in fact be just adding to future destruction.
It would in reality take hundreds of years for the historic regime to return to southern California. We also cannot be realistic in the notion to remove all residents out of Wildland Urban Interface areas. One might ask what can be done. One idea is for residents to be more responsible about the fire hazards on their own property. If every resident were to clear 30 feet in every direction around any structure, and keep the area around that 30 feet clear of any low lying vegetation, that would be a good start. If we are not going to let the forest cleanse itself through frequent small burns, we must clean it out ourselves it we do not want repeat incidents of the station fire.
Bibliograpy
Minnich, Richard A. Fire Behavior in Southern California Chaparral before Fire Control: The Mount Wilson Burns at the Turn of the Century. Annals of the Association of American Geographers. Vol. 77, No. 4 (Dec., 1987), pp. 599-618. Taylor & Francis, Ltd. Jstor, Web. 11/22/10.
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