Wild fires-yellowstone national park - Sample Essay
There are three components needed for ignition and combustion to occur. A fire requires fuel to burn, air to supply oxygen, and a heat source to bring the fuel up to ignition temperature. Heat, oxygen and fuel form the fire triangle. These are prerequisite conditions for any fire. A spark or even the sun’s heat alone sets off an inferno. The wildfire quickly spreads, consuming the thick vegetation and almost everything else in its path. What was once a forest becomes a virtual powder keg of untapped fuel.
Wildfire overtakes thousands of acres of surrounding land, threatening the homes and lives of many in the vicinity. For instance, the October 2003 fires in South California burned approximately 742000 acres and destroyed about 3,361 homes and about 26 lives were lost. Most of the Native Americans history is told and thought to be one that was characterized with fires, which used to burn down forests. These stories illustrate the threat posed by wildfires. 1. 2 Causes of wildfires There are various causes of the wild fires; while some of the causes are natural others could be considered artificial.
Artificial in the sense that they are triggered by human activity. 1. 2. 1. Natural causes The existence of fire within a landscape has been at least one of the greatest evolutionary factors influencing the composition of flora and fauna. More often than not, the natural fire causes include: lightening, sparks of fire originating from rocks, volcanic activity as well as the spontaneous combustion of organic substances and plant materials. Of these, lightening is considered the most effective factor in almost all the fires that have hit Southern California and anywhere else in the world.
This is so because the rate at which lightning strikes the earth is about 100 times a second averaging to about over 3 billion strikes per annum (Barbour, Burk, & Pitts 1980). It is said that there has been a dangerous mix of drought and wind, which has constantly hit for instance, the Southern California region for ages. According to a study carried out in 2006, researchers established that western federal forests had been burned about seven times more in 1987-2003 than in the proceeding 17 years. 1. 2. 2. Artificial Causes
Investigators agree that human activities, not lightning, are responsible for nine out of 10 wildfires… About three-quarters of the human-caused fires result from carelessness. ” (Inland Valley Daily Bulletin, 1 November 2003). Therefore human activities have played a role in triggering the fires. While there have been arguments linking other human activities, which have led to global warming, some scientists disagree with this school of thought. 1. 3 Report Aim The aim of this paper is to shed light on the possible causes of wild fires, their short term and long time effects.
It is important that people know the causes of these fires their effect on global warming, and how we can help avoid them or make slim their chances of occurrence 2. Fire Process and Behavior Wild land fires spread in two phases. First, convected heat causes the fire to spread from low vegetation such as grasses, underbrush and leaf litter (ground fuels) to higher vegetation (aerial fuels) such as tree branches, often via the mid-sized vegetation. In this phase, the fire grows vertically (see Fig. 1).
As the fire increases in intensity and size, involving fuels at all levels, radiant heat becomes the primary method of spread at both the aerial and ground fuel levels, and the fire grows laterally. Wind plays a major role in fire spread and can change over the life of the fire. Wind can: determine or influence the direction of fire spread, accelerate the flame onto new fuels, accelerate evaporation of moisture and dry out fuels in advance of the fire, carry embers and flaming material high up and deposit them in unburned areas, possibly igniting other fires.