a: San diego canyon ~
b: Blast Furnace
What: There have been many serious wild fires in Southern California over the years. San Diego has had its share. Why are these fires so destructive? There are a variety of factors. They are the canyon's shape, wind and fuel. The canyons in this region are long confined half tubes. When the Santa Ana winds start to blow, the canyons geometry channels and confines the air. The narrowing shape actually increases the wind speed and the amount of oxygen pushed through the canyon as any given time. The fuel is another factor. These canyons are often lined with Scrub Oak, which can become very thick after several years of heavy winter rain. But after years of drought, the plants survive by displacing their internal water with oil. They have been described as "gasoline soaked logs". With all these factors combined, hot dry winds channel down canyons filled with dry trees soaked in flammable oil. This is why the flames are so large and the temperatures can get so high. You couldn't design a better natural blast furnace.
Useful?
Writer: Lucretia
LCC: G
Where: Reference Link Has Evaporated
Date: Jul 6 2013 9:55 AM
# 3340 Critique Analogy