On August 26, 2009, at 3:30 p.m. authorities believe a transient began a small fire at the foot of an oak tree, near the southern fringe of Angeles National Forest. Fueled by the shrub and grassland ecosystems nearby (parched after a 100-plus degree heat wave), and stoked by the Santa Ana winds, the fire grew and spread to eventually engulf the entire Angeles National Forest. Over the ensuing three weeks what came to be known as the Station Fire tore through the mountainous region east of Los Angeles, consuming over 160,000 acres and displacing thousands of residents.
Angeles National Forest hosts a variety of habitats, including deciduous and evergreen forests, grasslands, shrub and scrubland. During a fire event, these vegetation types certainly play a role spreading, or containing of the fire. In the Station Fire, fire engineers observed that trees such as Junipers and pines have “a propensity for carrying fire.” Embers from the tops of trees are carried much further than those in generated in the low-lying Chaparral. In the dense Chaparral ecosystems containing shrubs and scrubs up to 6 feet tall, observers reported flames reaching as high as 75 to 100 feet into the air. Forested areas also tend to retain heat more so than Chaparral, which burns more intensely at a faster rate.
In the first four days of the blaze, the Station Fire exhibited the most expansion. By day five, the fire had occupied most of the area it would spread to by the time it burnt out several weeks later. So, fire expansion analyses can best be performed on data pertaining to the behavior of the fire over these first four days. The fire originated in a habitat with evergreen, deciduous, shrub and scrub habitat (phase I). Then, over a period of 12 hours, it moved northwest and southeast, following areas populated with evergreen and deciduous forest (phase II). During this time the fire neglected areas populated with shrub and scrub habitats. That is until sunset, when it quickly spread north through a valley with mixed shrub, scrub and grassland habitats (phase III). Moving northward past the valley, the fire encountered mixed deciduous and evergreen forests as well as an increase in slope/elevation (phase IV). At this point, the fire expanded west and east indiscriminately through both forests and chaparral, and high and low elevations.
These “patterns” should be taken with a grain of salt. Other variables such as diurnal wind direction, firefighting efforts, and slope surely played significant roles, and most likely diluted vegetation’s effects on fire progression; however, there are specific instances in the progression of the fire where vegetation type can be isolated as the most likely vehicle for fire expansion. During phase II, the fire spread across a valley and an elevated region, more or less omitting slope as a strong factor controlling the direction of the fire’s progression. Also, in phase II, the fire traveled in a direction that was not associated with wind direction. In other words, the fire traveled in an east-west direction, while winds traveled in a north-south direction. During phase II, the one consistency that seemed to appear was that the fire traveled along a line of trees (see Land Cover [NCLD 2001]). This pattern would lead one to believe that at times, land cover can play a role in fire spreading.
Eventually, through backfires, fuel breaks, liberal dumping of flame retardants and (most significantly) a moderate rainfall, the station fire was fully contained on October 16, 2009. In total the fire caused the deaths of two firefighters and injured 22 others. The Station Fire was the 10th largest in California since 1933.
Sources for maps:
U.S. Department of the Interior, 2010. National Resource Information Portal. National Park Service, 22 November; http://nrinfo.nps.gov/Map.mvc/GeospatialSearch.
U.S. Environmental Protection Agency (EPA), 2010. NCLD 2001 Land Cover Class Definitions. Multi-Resolution Land Characteristics Consortium (MRLC), 20 November; http://www.epa.gov/mrlc/definitions.html#2001.
Sources for report:
Associated Press (AP), 2009. Station Fire ‘goes where it wants, when it wants.’ The Los Angeles Independent, 01 September; http://www.laindependent.com/news/56493872.html.
CNN, 2009. Firefighters close to containing half of Station fire. CNN, 02 September; http://articles.cnn.com/2009-09-02/us/california.wildfire_1_angeles-national-forest-massive-fire-fire-officials?_s=PM:US.
KPCC Wire Services (KPCC), 2009. Station Fire still burns in Angeles National Forest. KPCC, 05 September; http://www.scpr.org/news/2009/09/05/station-fire-still-burns-angeles-national-forest/.
Molly Peterson, 2010. A year after Station Fire, botanist, volunteers protect changing forest ecology. KPCV Southern California Public Radio, 25 August; http://www.laindependent.com/news/56493872.html.