Fire perimeter

The fire happened in the center of LA County. That area is comparatively north of the large cities, and there is no large population around. The fire seemingly spread at the direction of north and east, the final fire area at 2^nd Sept. is over 600 km^2.  This fire is really serious because it was not controlled as fast as we can and the fire spread really quickly.

Influence of the highway and city area (“Los Angeles County Cities”, “Los Angeles County Highways”)

This map shows the fire influenced by the highway and city area. As I noticed that the fire spread from the south to the north, this phenomenon may cause by the wind when I first thought. However, as I look carefully at the fire area of each time, I found that the wind has no actual direction.  Then I found something about the highway. The highway is an artificial block of the fire at first. The northwest border of the 8.29-02:48 fire area is the same shape of the highway in nearby. It shows that the highway had somehow blocked the fire for a while and slowed it down at this direction. The same condition appeared at the 8.29-14:55 area and 9.07-00:58 area. The next factor influences the spread of the fire is the city area. The 3 citied which were just near the source of ignition slightly were influenced by the fire. This is because those cities are areas of comparatively large populations. There are more constructions which made fewer woods. So, fire was unable to spread there.

Influence of the water(“Los Angeles County Rivers and Streams”)

This map actually shows another factor, water. As LA County has no such big lakes or rivers, fires cannot be controlled safely by those small lakes. At the border of the 8.30-00:25 fire area, there are a bunch of small lakes or wetlands. Although the lakes didn’t actually stop the fire, for, the next 2 day after, the fire spread over the lakes, lakes, to some extend delay the fire. The 8.30-00:25 clearly shows that, fire spread just to the north and east, but it did not appeared between these 2 direction which made it strange. The fire cannot simply be put out by the water or sand because some of the fire is made of arson and fuel can spread very quickly. In the same reason, the water body cannot influence the overall condition but can stop the fire from some direction.

The threat

The North West part of the fire source is forest.  In that area, fire is easy to spread. And because those places have no water body, it is really hard to bring water to put out the fire. If the fire go all through the forest, there must be a great lose. And by the way, the highway is cut through by the fire, which means that some parts were broken by the fire.

In conclusion, the wildfire is spread really fast that only in 4 days can it cover area more than 600 square kilometers. Water bodies, highways and city areas had influenced to some extent. Although they can hardly stop the wildfire, they slow it down and block its spread to limit its direction which, in the same way, help firefighters to control the fire.

Reference

Fire perimeter.Greninger, Mark. “All Station Fire Perimeters (as of September 2, 07:02) Complete set.” Los Angeles County Enterprise GIS. 2 Sept. 2009. Web. 29 Nov. 2011.

Los Angeles County Highways. Mapshare: UCLA's Spatial Data Repository. UCLA GIS.  2 Sept. 2009. Web. 29 Nov. 2011.

Los Angeles County Cities. Mapshare: UCLA's Spatial Data Repository. UCLA GIS. 1 Sept. 2009. Web. 29 Nov. 2011.

Los Angeles County Rivers and Streams. Mapshare: UCLA's Spatial Data Repository. UCLA GIS. 1 Sept. 2009. Web. 29 Nov. 2011.

Los Angeles County. Mapshare: UCLA's Spatial Data Repository. UCLA GIS. 1 Sept. 2009. Web. 29 Nov. 2011.