The Spread of Wildfires

California is raging with wildfires today. Before 2021, 7.1 million acres were burned in the United States, and even more have burned in the past two years. A direct result of climate change, these flames have occupied a considerable part of Northern California, and they are even threatening the famous Yosemite National Park. But how do these fires start, and what steps are being taken to contain them?

To understand how to suppress fires, we first need to know how they are formed. Think of a wildfire as a food you like to cook. It needs three key ingredients, and if those ingredients are put together, it creates a blazing fire. This is known as the fire triangle. A wildfire requires heat, oxygen, and fuel. In California, temperatures easily reach 80 degrees Fahrenheit, which is the perfect temperature to start a fire. Oxygen is found in our atmosphere; about 21% of the air we breathe is made up of oxygen. Fuel is not limited to the gasoline we put in our cars; it is any flammable material, living or dead, that emits a vapor and can be ignited. Trees, grasses, and even our houses can sustain or carry flames. These materials combust, or produce heat, from burning. Along with these three requirements, there are many other factors that can contribute to the intensity of forest fires. Among those are wind, humidity, and topography – the shape of the land. A rocky topography can hinder a fire from spreading to nearby areas, and an uphill slope can spread fire much more quickly than a downhill slope.

A fire needs all three parts of the fire triangle to continue blazing, so the best solution to stop a wildfire is elimination of one or more of the sides of the triangle. This will ensure that the fire cannot spread. So how do firefighters do this? One method is by building a firebreak around the fire. A firebreak is a section of land where all the fuel has been eliminated. If there is no fuel, then the fire triangle is incomplete, and the fire cannot spread to neighboring areas. Another tactic is to remove heat. This is done by applying water or fire retardant either on the ground or in the air. You’ve probably seen pictures of airplanes releasing a red substance from the air onto a stretch of forest. That red substance is fire retardant, and its main ingredient is called ammonium phosphate. Wildfires are dangerous forces of nature that seem to have no end, and no matter what method is used, the main goal is to break the fire triangle and suppress the fire’s spread.

Source:

California Department of Forestry and Fire Protection (CAL FIRE). “2022 Incident Archive.” Cal Fire Department of Forestry and Fire Protection,
https://www.fire.ca.gov/incidents/2022/ opens in a new window

Moore, Andrew. “Explainer: How Wildfires Start and Spread.” College of Natural Resources News, 3 Dec. 2021, https://cnr.ncsu.edu/news/2021/12/explainer-how-wildfires-start-and-spread/#:~:text=Heat%20brings%20these%20fuels%20to,releases%20heat%20and%20generates%20combustion opens in a new window

“Suppression.” U.S. Department of the Interior, 20 Apr. 2022, https://www.doi.gov/wildlandfire/suppression#:~:text=Firefighters%20control%20a%20fire’s%20spread,(using%20helicopters%2Fairplanes) opens in a new window

Scientific Peer Review by Alysia Mandato

Aneri Shethji:

Aneri Shethji is a 10th grader at North Allegheny Intermediate High School. She is very passionate about science and writing and enjoys getting involved with the community. In her free time, Aneri spends time with friends and family and loves getting outside. She can’t wait to learn more about all that science has to offer, and help others learn it too!