Week 4 Lab: Fire Analysis

Following the 2009 wildlife in La Canada Flintridge, California fire (also considered the “Station Fire”), authorities and local governments in Los Angeles County assessed the factors that led to such a hazardous and destructive fire. This assessment revealed that some of the major factors which attributed to the Station Fire were 1) the area’s increased or high slope in comparison to other less sloped areas and 2) the area’s types of land cover. Beginning my process of assessing slope and land cover for the Station Fire, I downloaded data from the California Department of Forestry and Fire Protection. I included data such as the widest extent of the station fire (perimeter), a digital elevation model (DEM) of Los Angeles County, and data featuring land cover types for Los Angeles.

From the Los Angeles County DEM, I projected the raster to obtain the slope values in percent rise to reveal that this portion of the Angeles National Forest had the most sloped area compared to other areas of Los Angeles County. When reclassifying the land cover data types, I assigned shrubs to have the highest fire risk and water having the least. Displaying the land cover types in Los Angeles County showed that nearly all of the land within the Station Fire perimeter was covered in shrub or hardwoods, which were the vegetation types with highest risk of burning. After preparing the slope and land cover maps, I combined the data and overlaid them to calculate the combined risk attributed by slope and land cover. As shown in the inset of LA County, the area of Angeles National Forest had the greatest combined fire risk, and the Station Fire perimeter is located entirely within this high risk area.

During the preparation of this fire assessment, some of the challenges I faced were largely based on software. For instance, I had to calculate slope/vegetation combined risk multiple times because ArcGIS wouldn’t allow the file name to be saved because it included too many characters. The raster calculator had a pop-up to indicate the software wouldn’t save the file, but the message it displayed didn’t make sense. Aside from such issues, there weren’t too many other challenges, and the data I analyzed revealed that these risk factors very obviously led to such a high risk for the Station Fire to occur. Studying fire ecology typically shows that over time, it is natural for areas of forest and shrub to have small fires in order to maintain the ecosystems of these areas. Some hardwoods require fire to open and release their seeds and continue growth within an area, thus allowing for a cycle of burn and regrowth. Suppressing forest fires will tend to lead to large fires that will burn long, such as the case with the 2009 Station Fire.