Riya – Year 10 Student
Editor’s Note: Year 10 student Riya writes here for the GSAL Science Magazine, looking at a remarkable breakthrough in wildfire fighting technology. As global warming increases the number, scale and intensity of wildfires, researchers at Stanford University have developed a gel which could be used to help prevent wildfires in the future. CPD
[Featured image: 2013 photo of the Alder Fire in Yellowstone National Park. (Flickr: Public Domain)]
Presently, global warming is causing a rapid increase in the number of wildfires. Wildfires can have devastating effects not only on the soil and wildlife, but also the residents of the region. The recent California wildfires have already burnt land across 250,349 acres, leaving large areas without any power for days. Some people have been injured and many homes have had to be evacuated. To combat this, researchers at Stanford have developed a gel which could be used to help prevent wildfires in the future.
This gel-like fluid is environmentally benign[1] and uses only non-toxic material. It also has the capacity to decrease the number of fires and the severity of them. At the moment, fire retardants are easily washed away by rain or blown away so they don’t last long enough for them to be used as prevention, but this gel has been designed in a way that it stays on the vegetation for the entire wildfire season, even if it is exposed to rain or wind.
The gel is mainly made of cellulose-based polymers[2] and colloidal silica particles[3]. The cellulose is from plants and the silica is essentially just sand so the components of the gel are non-toxic. “What happens is the polymers cross-link between the particles—I often refer to it as sort of a molecular Velcro,” says Eric Appel, the professor at Stanford who led the research. The polymers make links between the particles, creating a gelatinous structure. This allows the fluid to be applied with standard agricultural spraying equipment or by aircraft. The material will stick to the vegetation and last the entire fire season. Then it will eventually degrade.
Appel didn’t originally set out to stop wildfires, but actually was trying to prevent people from getting disease. He was working on gels that could carry drugs into a patient’s body to prevent them from disease when his brother-in-law, a fire prevention forester, asked if it was possible to load these gels with fire retardants. Appel thought it was a good idea and pursued it, developing the gel over three years.
The gel was tested on grass and chamise[4], two types of vegetation that catch fire frequently. They found that the treatment provided full protection against the fire even after half an inch of rain. Typical fire retardants would provide little protection under the same conditions so this gel definitely has the capacity to reduce the number of fires that start.
Currently, the only way to fight wildfires is reactively. We wait for the fire to start and then try to put it out by dropping fire retardants from planes. The problem with this is that it still causes severe damage and is extremely costly. This gel, along with the strategy of treating the high risk areas, could provide us with a method of preventing the fire before it even starts. By treating the fire prone areas, we would be treating only a small amount of land but preventing most fires from happening. For example, roadsides are a high risk area because people throw cigarettes out of their window and heavy vehicles sometimes set fire to the vegetation with their undercarriage. The fire then spreads further from where it started at the road so, by preventing fires by the roadside, many fires are prevented.
This gel has the potential to save the property, lives and livelihoods of many people. It is a less expensive and more effective alternative to any existing fire retardant. It will allow us to proactively prevent wildfires instead of just reacting to them. As Alan Peters[5] says, “We don’t have a tool that’s comparable to this.”
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[1] It is not harmful to the environment.
[2] Polymers are substances which have a structure mainly made of a big number of similar units bonded together.
[3] A colloidal silica is a suspension of fine silica particles in a liquid phase.
[4] A shrub common in California that burns easily.
[5] Alan Peters is a California Department of Forestry and Fire Protection (CalFire) division chief who monitored some of the testing using the gel.
References
https://en.wikipedia.org/wiki/2019_California_wildfires
https://www.smithsonianmag.com/innovation/gel-could-prevent-wildfires-180973278/
https://www.wired.com/story/wildfire-gel/
https://www.conserve-energy-future.com/causes-effects-and-solutions-of-wildfires.php
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