As the massive Dixie Fire raged through the woods and mountains of northern California last August, firefighters sent a small drone down into a difficult-to-access gully. The aircraft carried thermal imaging sensors, letting the firefighters get a better sense of what the fire was really up to — and what to do in response.
“The perimeter of the fire itself — where is the fire now? We don’t necessarily know. Can this aircraft maybe go out and tell us where it is right now?” said Joey Mercer, a research psychologist at NASA’s Ames Research Center in California, who spent part of 2021 joining fire crews at some of the season’s most devastating wildfires — Dixie, McCash, Caldor and Windy, which collectively burned an area bigger than Rhode Island.
Mercer heads up a NASA project aimed partially at incorporating drones into fighting wildfires, a trend that appears to be picking up steam. There are now various agencies and companies testing or using drones in virtually the entire life cycle of a wildfire, from early detection and prevention through fighting active blazes to cleanup and reforestation. The idea is that these uncrewed aircraft can streamline many aspects of fire management in a world where climate change is supercharging traditional fire patterns. Quicker, smarter, safer, cheaper — all crucial upgrades on a burning planet.
Between 1983 and 1999, wildfires burned just under 3 million acres of American land every year, according to data from the National Interagency Fire Center. From 2000 through 2021, that average jumped to more than 7 million acres. This means increased danger to people and the places we live, but also to firefighters themselves; between 2010 and 2019, there were more than 400 wildland firefighter deaths and an ever-increasing exposure to dangerous smoke inhalation. Drones might offer ways to reduce those risks while improving management of fires from start to finish.
The blazing new normal
As the climate has warmed, longer and deeper droughts have combined with higher temperatures and more heat waves to prime many parts of the world for wildfire. Growing seasons are longer than they used to be, offering up more burnable material. And climate change-fueled pest outbreaks like that of the mountain pine beetle kill off millions of trees and leave them standing there, hundred-foot-tall tinder-dry matchsticks just waiting for a spark.
Along with the obviously increased danger associated with these altered landscapes, this also means rapidly growing costs. The average annual federal costs of wildfire suppression are now more than $2 billion — and that doesn’t include state agency costs. The Forest Service’s 2023 budget request includes $2.7 billion for “wildland fire management,” an increase of $751 million from the previous year, and specifically notes that climate change is “increasing the severity and frequency of wildfires.” Anything that can help firefighters work smarter rather than harder might help bring down those costs.
The cheapest way to fight a wildfire is to prevent it. Drones “give you a possibility for more frequent monitoring, and also detecting smaller fires,” said Eija Honkavaara, a professor of remote sensing and photogrammetry at the National Land Survey of Finland. She is among the leaders of the FireMan consortium, a multi-institute project investigating how to use drones primarily for the early detection and prevention of large wildfires. This is of particular relevance in a country where almost three-quarters of the land is forest.
Wildfires in remote areas are often detected by satellite or crewed aircraft — both of which provide limited coverage. “Satellites, they are maybe covering the area once or twice per day,” Honkavaara told Grid. “We can detect [the fires] earlier.”
The FireMan project is bringing together a variety of experts at several Finnish universities and institutes to design a system where a swarm of small drones — ranging from around five or 10 to potentially more than 100, Honkavaara said — could autonomously patrol an area deemed to be at risk of wildfire, using thermal imaging and other sensors to find hot spots. Early detection of fires could allow firefighter teams to rush to an area and suppress the blaze before it balloons into something much less manageable and much more dangerous.
The FireMan team will incorporate artificial intelligence tools that will help predict the movement of a fire once it starts, helping guide the response, as well as novel communications systems between the drones and the responders on the ground that are capable of functioning well beyond the reach of cell towers or Wi-Fi. The team will test the system this year in a series of prescribed burns — purposely set fires. Honkavaara hopes that within a few years, it will be operational in the field.
When a large wildfire is already underway, the response can often involve multiple crewed aircraft — large tankers to drop water or fire retardant, helicopters bringing fire crews to relevant areas, and so on. NASA’s Mercer said coordinating these aircraft involves a “trust but verify” system, where the pilots are both talking to each other and visually confirming each plane or helicopter’s location. Drones are too small for such visual confirmation, so new systems need to be developed to make sure every aircraft is aware of the others, crewed or not.
NASA’s STEReO project, or Scalable Traffic Management for Emergency Operations, is working on just such systems. The drones deployed in wildfires can streamline or improve a number of important roles, from mapping the details of the fire to dropping Ping-Pong ball-sized containers of fuel to start small prescribed burns that help slow or prevent larger fires. And importantly, they can turn a stop-and-start process into a continuous effort.
Crewed aircraft require visibility, which can restrict their use. “Because of that they’re only limited to four to six hours a day, during clear visibility conditions,” Parimal Kopardekar, director of the NASA Aeronautics Research Institute, told Grid. “The fire continues 24/7, obviously. We want to change the paradigm to fight the fires on a continuous basis.”
This could eventually see larger drones carrying water or retardant to drop on fires at night, a sort of “second shift” of firefighting to carry on when the crewed aircraft are grounded. And when day breaks and the big planes are back in the sky, they will work in concert with smaller drones, where before the two could not coexist.
The goal, Mercer said, is a sort of digital equivalent to “trust but verify.” “You can’t see me out your window, but you could see me on some other type of electronic device,” he said.
In remote areas where communications are difficult and line-of-sight to global positioning satellites may be compromised, larger drones could eventually be used at high altitudes to create a sort of ad hoc communications network, Kopardekar said, allowing the other aircraft below to talk to one another and position themselves appropriately.
There are still challenges ahead. Researchers are still designing these communications systems and learning exactly how firefighters might most benefit from drones in the field. The STEReO team has partnered with a number of organizations to work through some of those issues, including the Forest Service, Cal Fire and others. Other government agencies are also in on the act: The National Advanced Fire and Resource Institute now hosts the National Interagency UAS [unmanned aerial system] Training Program, which includes drone flight school, an aerial ignition class and more.
“This is one area where aviation actually can help fight the emergency,” Kopardekar said. In other disasters, such as floods or earthquakes, aircraft can help with search and rescue — but their use more or less stops there. “In this case, we not only can do search and rescue at the wildland-urban interface, but we can actually use aviation assets to suppress the fire. And that’s why it’s so exciting for us — particularly if we use drones, you can actually suppress the fire.”
After the fire
Even if drones do end up helping firefighters contain and suppress large wildfires, the world’s forests are still going to burn as the climate warms. It is after a fire is out that drones may have one more role to play: reforestation. Trees are among the best tools available for pulling carbon dioxide out of the air, so putting them back after a fire is a no-brainer climate solution. But planting trees after a wildfire is a process often hampered by varied and difficult-to-access terrain; drones can skip right past that problem.
“They can navigate that terrain quickly,” said Grant Canary, the CEO of a company called DroneSeed. “They can go up and down slopes quickly. They don’t disturb soils. They don’t get bogged down by water. That’s where drones have a very significant impact.”
DroneSeed has worked with large timber companies, tribal nations, state and federal agencies, and even owners of small “family forests” to rapidly replant native trees in the wake of wildfire. Other companies can turn to them to purchase carbon offsets, paying to plant trees that ideally will spend the next century pulling CO2 out of the sky — DroneSeed recently announced a 50,000-tonne carbon-offset deal with internet commerce company Shopify, which will focus on planting in a spot in Oregon damaged by the 2020 Beachie Creek Fire.
The technology to make this happen is not trivial. DroneSeed has a Federal Aviation Administration permit to use heavy-lift drones capable of carrying 57 pounds of payload into hard-to-reach areas — the only such permit to date, according to Canary.
“These are not something you can buy at Best Buy,” he said. “They’re about 8 feet in diameter — so they’re taller than me, stood up on end.”
The company first sends smaller drones equipped with lidar sensors, which use pulsed lasers to map the terrain below to avoid dropping seedlings on rocks, rivers or other undesirable spots. The larger drones then head out and drop seedlings encased in what Canary said resembles a hockey puck. This protects the seedling from predation from birds or rodents and allows it to take root. They plan to monitor their plantings for years afterward, to ensure the trees are actually growing.
Other companies have similar goals. For example, in Canada, Flash Forest hopes to plant more than 1 billion trees via drone by 2028. In Spain, where wildfires are also an increasing problem, a company called CO2 Revolution says its drones can replant up to 100,000 trees in a single day.
As the climate continues to warm, experts expect further increases in the number of fires and acres burned, so the opportunities to incorporate drone technology will continue to expand. “It’s about making [firefighters’] efforts more effective,” Kopardekar said. “The community does a tremendous job. They put in huge effort day in and day out. And we owe them good technologies and tools to continue to fight. That’s the goal.”
Thanks to Lillian Barkley for copy editing this article.