(Note: The numbers that appear throughout the written response that are directly adjacent to a word correlate with the annotated bibliography that is posted below. All sources in the written response have been cited using this format).
The Station Fire broke out in the Angeles National Forest in Los Angeles County on August 26, 20091 and was presumably caused by arson. As illustrated on the attached map entitled “Spreading of the 2009 Station Fire and Surrounding Metropolitan Areas,” the fire broke out less than two miles northeast from La Crescenta-Montrose and Pasadena near the Pasadena subdivision of Los Angeles County. The fire broke out within the dark red zone on the map, and then spread in a northern direction, with a lesser distance traveled to the east. The fire was not completely contained until October 16, 20091. By this time, the fire has engulfed 160,577 acres of land, leaving those acres significantly barren with minimal potential for immediate regrowth1.
For this report, I focused on the spreading of the fire from August 29th, 2009 at 2:48AM (which is three days after the initiation of the fire) to September 2nd, 2009 at 7:02AM. Initially looking at the spreading of the fire, it is apparent that the fire did not spread to the southwest, instead growing toward the north and the east. This reason for this is exemplified by the presence of urban regions on the map. In order to protect the urban regions, the firefighters established a front against the fire along the border of La Crescenta-Monrose, Pasadena, La Canada Flintride, and Altadena, all within the Pasadena subdivision of Los Angeles County. On September 2nd, 2009, the Los Angeles County Fire Marshall ordered the evacuation of these urban regions, which included the evacuation of 12,000 structures that were potentially threatened by the spreading of the fire1. The map entitled “Spreading of the 2009 Station Fire and Surrounding Metropolitan Areas” shows that the fire spread toward non-urbanized regions that were boasting natural terrain.
Both elevation and slope can affect the spread of fire. An increase in elevation typically yields a decrease in the spread of fire, as higher levels of elevation yield reduced temperature levels and amounts of fuel availability while moisture and precipitation tend to increase2. On this map, elevation is symbolized by a transparent overlay, reaching its highest elevation (3302.72 ft) when the shading is the darkest, and it’s lowest elevation (-0.785875 ft) when shading is the lightest. The shading of elevation on the map entitled “The Impacts of Elevation, Rivers, and Roads after the 2009 Station Fire” reveals two things. Firstly, when the shading is the darkest at highest elevations, this represents a mountain ridge or a peak, from which point elevations decrease on all other sides. This is important as that means that on all sides of these regions, fuel availability and temperature increase while moisture and precipitation decrease, yielding more opportune fire conditions on all sides. Secondly, the closer the lightest shaded regions are to the darkest shaded regions, the greater the slope is in the area. With reference to the map entitled “The Impacts of Elevation, Rivers, and Roads after the Station Fire,” we can clearly see some moderate signs that suggest that elevation and slope impacted the route the fire spread from August 29th, 2009 to September 2nd, 2009. For example, the spreading of the fire from August 29th, 2009 at 2:48AM to August 30th, 2009 at 12:25AM seems to exhibit a pronounced movement along a ridge that extends northwest from the fire’s initial location. This movement is likely pronounced along this ridge and into surrounding regions given that the surrounding regions all have lower elevations than the ridge and all possess conditions that are increasingly ideal for the spreading of the fire. Elevation may have also played a role in the spreading of the fire between August 30th, 2009 at 9:14PM and September 1st, 2009 at 12:58AM, as the two eastern points of the fire on August 30th, 2009 at 9:14AM contain mountain ridges and peaks. Notably, the peak to the east of the initial fire range appears to have a substantial slope, as the transition from lighter to darker shading occurs over a small distance. Due to the rapid increase in elevation at this juncture, the fire may have slowed down due to a quick decrease in factors like fuel availability and temperature. The fact that these points lie along this time border in the fire’s spreading implies that the spreading of the fire may have temporarily slowed as it tried to pass over these regions. While elevation is certainly not the sole factor impacting the spreading of the fire, the path the fire spread in relation to the peaks of elevation and slope seem to have played at least a partial role in affecting the spread of the fire.
When a forest fire occurs, the spreading and the immediate devastation from the event are important to note; however, residual impacts that occur over time after the initial devastation are also important to acknowledge. The USGS, since the termination of the Station Fire, has been collecting data from three monitoring sites: one referred to as Arroyo Seco, Pasadena, California, a second called Dunsmore Canyon Site 1, Glendale California, and a third called Dunsmore Canyon Site 2, Glendale California3. Surveyed data from November 27th, 2009 to December 3rd, 20093 (about six weeks after the conclusion of the fire) shows an average loss of water concentration of .05m3/m3. After a fire, the drying of soil can loosen soil particles, which can then be lost through wind or other forms of erosion. Due to the increased likeliness of erosion following the termination of a forest fire, it is important to note locations of rivers and roads as they serve as channels for massive erosion events, eroding debris, and flash flooding4. Because of this, it is important to note not necessarily their location as much as the direction where they head. The direction that rivers travel can be determined by comparing the elevation of two points along a river or a road. However, given the shortage of roads in the region that was impacted by the Station Fire from August 29th to September 2nd, I will focus this brief analysis instead on solely the rivers. Looking at the map entitled “The Impacts of Elevation, Rivers, and Roads after the 2009 Station Fire” in correlation with the map entitled “Spreading of the 2009 Station Fire and Surrounding Metropolitan Area,” we can tell that the majority of the rivers in the area impacted by the Station Fire from August 29th, 2009 to September 2nd, 2009 traveled downhill toward the non-urbanized regions north of the incident’s location as well as downhill toward the center of the damaged site. Based on this, we can reason that despite the 2009 Station Fire’s close proximity to dense urban regions in northeastern Los Angeles County, that these urban regions were likely impacted minimally by the effects of erosion or flooding; however, the non-urbanized regions north and at the site of the incident, due to the paths of the rivers, probably received the bulk of the pollution in the months that followed.
By simply looking at a basic map of the 2009 Station Fire, such as the one titled “Spreading of the 2009 Station Fire and Surrounding Metropolitan Areas,” we can interpret basic information, such as the movement of a fire across land, it’s distance from infrastructure like roads and highways, which regions surrounding the fire are more urbanized than others, and the location of natural features in relation to the movement of a fire. In this case, we can tell that despite the Station Fire’s close proximity to highly urbanized regions in northeastern Los Angeles County that the fire spread into the non-urbanized regions of the Angeles National Forest. Then, when examining a map, such as the one titled “The Impacts of Elevation, Rivers, and Roads after the 2009 Station Fire” which shows a physical change across a geographic area, we can then assess how the physical alterations impacted a certain incident, in this case, the spreading of the 2009 Station Fire. For the 2009 Station Fire incident, we were able to see how elevation affected both the spread of the fire and the paths that carried erosion that occurred after the fire due to a loss of moisture in the soil. The map seems to show that elevation had an impact as the fire appeared to spread more readily toward areas without rapid increases in elevation. While the map does not blatantly show the paths that erosion will take after the conclusion of the 2009 Station Fire, the map can be used as a tool in this instance to draw conclusions. For example, by showing the specific locations of rivers and the changes in elevation across the area of the fire, one can infer the direction that erosion and flooding will travel after the termination of the fire.
(Note: The numbers that appear throughout the written response that are directly adjacent to a word correlate with the annotated bibliography that is posted below. All sources in the written response have been cited using this format).
References for Written Response:
1. "Station Fire." Inciweb - Incident Information Web. U.S. Forest Service. Web. 2 Dec. 2011.
2. Long, A., and D. Kennard. "Effects of Topography on Fire Intensity and Rate of Spread." Forest Encyclopedia Network, Knowledge & Application. Web. 3 Dec. 2011.
3. "Soil Moisture." Landslide Hazards Program. United States Geological Survey. Web. 02 Dec. 2011.
4. "Station Fire Fact Sheet." United States Forest Service. United States Forest Service. Web. 03 Dec. 2011.
References for Shapefiles Acquired for Mapping:
Greninger, Mark. Los Angeles County Enterprise GIS (file: station_fire_perimeters) .
“All Station Fire Perimeteres (as of September 2, 07:02). [ERSI Shapefile]
http://egis3.lacounty.gov/eGIS/index.php/category/gis-data/fire/
MAPSHARE – GIS at UCLA. Maphshare: UCLA’s Spatial Data (file: LACounty_highways). [ERSI Shapefile] http://gis.ats.ucla.edu//Mapshare/Default.cfm#
MAPSHARE – GIS at UCLA. Maphshare: UCLA’s Spatial Data (file: LACounty_rivers). [ERSI Shapefile] http://gis.ats.ucla.edu//Mapshare/Default.cfm#
MAPSHARE – GIS at UCLA. Maphshare: UCLA’s Spatial Data (file: LACounty_streets). [ERSI Shapefile] http://gis.ats.ucla.edu//Mapshare/Default.cfm#
MAPSHARE – GIS at UCLA. Maphshare: UCLA’s Spatial Data (file: LACounty_airports). [ERSI Shapefile] http://gis.ats.ucla.edu//Mapshare/Default.cfm#
MAPSHARE – GIS at UCLA. Maphshare: UCLA’s Spatial Data (file: mjrrds). [ERSI Shapefile] http://gis.ats.ucla.edu//Mapshare/Default.cfm#
United States Geological Survey. USGS – Seamless Data Warehouse (file:NED_14409799). [ERSI Shapefile] http://seamless.usgs.gov/website/seamless/viewer.htm
US Census Bureau – Geography Division. Tiger/Line Shapefiles for: Los Angeles County, California (file: tl_2009_06place). [ERSI Shapefile] http://www2.census.gov/cgi-bin/shapefiles2009/county-files?county=06037
US Census Bureau – Geography Division. Tiger/Line Shapefiles for: Los Angeles County, California (file: tl_2009_06037cousub). [ERSI Shapefile] http://www2.census.gov/cgi-bin/shapefiles2009/county-files?county=06037
