By Carsten Brinkschulte, CEO and Co-Founder, Dryad Networks
With wildfires becoming more common, more intense and more deadly, it is more important than ever to invest in wildfire detection. Quick detection is key to protecting lives and property, but how do we spot fires, and how can we improve?
Watchtowers
By setting up multiple watchtowers, it becomes possible to triangulate and dispatch firefighters to the exact location of a fire. We have used this approach for a long time and it has proven pretty reliable. Modern technology is now taking over this role, utilising cameras mounted on the towers, often equipped with Artificial Intelligence (AI) to detect smoke and automatically signal the fire service.
Advantages
Watchtowers, whether manned by humans, cameras or AI, have the advantage of being able to overlook a large area, so relatively few of them are needed to keep watch over a large forested area.
Disadvantages
The main problem with using watchtowers for wildfire detection is that the smoke has to rise above the tree canopy to become visible, which means the fire is already quite large. Tree canopies act like a blanket, holding down the smoke. It’s only when the fire is large enough that it creates an updraft strong enough to push the smoke above the tree canopy.
Satellites
Observational satellites can have geostationary orbits, where the satellite is in a fixed location relative to Earth, or Low Earth Orbits (LEO), where the satellite moves relative to the Earth.
Each type of satellite uses camera technology to keep a lookout for wildfires. Geostationary satellites will keep watch over one area of forest while a LEO satellite will work as part of a network to provide global coverage.
Advantages
A single geostationary satellite can provide coverage of around a quarter of the entire surface of the Earth. Given their wide field of view, satellites are fantastic at tracking the progression of wildfires.
Disadvantages
Geostationary satellites orbit the Earth at distances of around 35,888km. At this distance, a single pixel is the equivalent of 500x500m. This means that the fire already needs to be very large before the satellite can detect it.
LEO satellites are much closer to the ground ─ around 600km above the Earth’s surface ─ so can provide substantially better resolution. Unfortunately, since they are constantly on the move relative to the Earth’s surface, they only pass each area once every six hours. In six hours, a fire could have progressed from the smouldering stage to become very large and, potentially, unstoppable. As such, satellites are not ideal when it comes to early detection of wildfires.
Gas Sensors
Gas sensors are a relatively new technological approach to wildfire detection, functioning like digital noses that can ‘smell’ a fire. They are positioned in forests below the tree canopy and use AI to accurately detect smoke from fires.
These gas sensors are typically solar-powered, allowing them to be positioned anywhere and run for more than 10 years without the need for an external power supply or battery swap.
Advantages
The main advantage of gas sensors is that they can detect wildfires as early as the smouldering stage; they can be extinguished much more easily and effectively before they spread and cause real damage.
The other advantage of gas sensors is their cost. At less than $100 per sensor, they are the cheapest of the three detection methods, in particular for detecting human-induced wildfires in the wildland urban interface.
Disadvantages
The disadvantage of gas sensors is their limited range in comparison to, say, satellites. One sensor is needed for each five hectares of woodland (more in high-risk areas)
Gas sensors are, therefore, best suited to cover high-risk, high-value areas in the WUI ─ places where people hike, camp or drive, power lines and railroad tracks, as well as anywhere else where fires have proven more common.
Combination is key
There is no silver bullet that will solve the growing wildfire crisis on its own, but by combining multiple solutions, it is possible to create an optimal system. The advantages of one approach can be used to cancel out the disadvantages of another.
By combining all three approaches, we could effectively manage the majority of wildfires before they become too large and unmanageable. Not only would this save forests but it would also save homes, livelihoods and lives, both of the public and of firefighters tackling the blaze.
Website: https://www.dryad.net/
https://www.facebook.com/dryadnetworks/
https://twitter.com/DryadNetworks
https://www.linkedin.com/company/dryadnetworks/
Sources:
https://wfca.com/articles/how-fast-do-wildfires-spread
https://www.iii.org/fact-statistic/facts-statistics-wildfires
https://hrcak.srce.hr/file/353960
https://www.dryad.net/wildfiresensor
https://svs.gsfc.nasa.gov/11107
https://www.fao.org/documents/card/en/c/ca8985en
