It’s 42 degrees Celsius, it hasn’t rained for weeks and the risk of forest fire is serious. In this dusty corner of southeastern Spain in August, the grass has turned yellow and the cereal fields are dying in the heat after months without rain. Walking down the road, it feels like your skin is burning with the heat.
But on the outskirts of Ribarroja, a small town near Valencia, there is an unusual line of defense against a possible fire. Above the trees near the edge of town are a series of huge green towers that look like streetlights. They act as mammoth water sprinklers, dousing the trees and bamboo plants below with recycled water to reduce the chance of fire. They are supplied with recycled water from houses near Ribarroja and neighboring Paterna.
It is the largest forest fire defense system in Europe, made up of 40 towers that surround the towns, the largest being 24 meters high. Known as the Guardian Project, it protects urban areas surrounded by trees or other vegetation from the devastating effects of a wildfire by hydrating the plant life and creating a natural barrier. With climate change increasing the threat of wildfires across the continent, Guardian-style defenses could become a fixture in Europe’s high-risk areas in the future.
Watering vegetation can delay the spread of a fire because plants that contain greater amounts of moisture require more energy from a wildfire. Other factors affect the spread of a wildfire (wind speed is crucial, for example), but generally the drier the vegetation, the faster a fire will consume the landscape.
“Water consumes part of the energy of a fire,” says Ferrán Dalmau, managing director of forest fire consultancy Medi XXI GSA, which developed the Guardian system. “If a plant is better hydrated, it will slow down the fire.” But Dalmau warns that the system will not put out the fire. Guardian can slow down and help control a fire, but it does not replace the need for firefighters to intervene.
In fact, hidden among the undergrowth is Guardian’s second line of defense: an array of sensors. These relay information to local fire authorities in real time, 24/7, about plant moisture levels and the resulting fire risk. Based on this information, firefighters are put on a higher alert level if the risk increases. Citizens can also receive fire risk updates through the Telegram messaging service.
After showing me the Guardian system on site, Dalmau takes me to his office and shows me how, thanks to these sensors, the system can indicate areas that could be affected by a fire, as well as simulate how it might evolve the fire. Dalmau shows me a computer graphic of the area we just walked. The irrigated area is brown, which means it is safer, but the rest around it is bright red, which means it would be at maximum risk of fire. An algorithm calculates fire risks.
After a prolonged drought and scorching temperatures, 2022 has been the worst year for forest fires in Spain. So far this year, 275,000 hectares have burned, roughly four times the area of New York City, which is more than four times the country’s annual average, according to the European Forest Fire Information System. Tens of thousands of people have been forced to evacuate their homes because of the flames.