Haze from the forest fires blanket most parts of the landscape. Aulia Erlangga/ CIFOR

LIMA, Peru—Sending small unmanned drones to fly over tropical forests has great potential for enhancing community-based forest monitoring—and in measuring carbon for climate change mitigation efforts, experts said at an event on the sidelines of the recent UN climate conference.

“They can monitor and measure many things, including carbon; they are fast; they’re cheap; they’re immediate—and they will save an enormous amount of drudgery and labor,” said Michael McCall, a senior researcher at the Universidad Nacional Autónoma de Mexico (UNAM) and one of the authors of a new paper on the subject.

The word “drone” has a certain amount of baggage—from its association with U.S. military operations—but these researchers believe their peaceful application can reap dividends for forest conservation and forest communities.

Monitoring changes in forest cover is also an essential part of REDD+, a results-based scheme that would reward communities for reducing carbon emissions from deforestation and forest degradation.

It has often been argued that getting local people to do that monitoring themselves can be as accurate—and much cheaper—than having scientists do it.

And drones have several key advantages to monitoring from the ground or a satellite, McCall said.

Fixing a small camera to a model-airplane-sized drone and flying it at a height of 50 to 300 meters can yield extremely high-spatial-resolution imagery, the study found. At this resolution, specific trees and canopy gaps can be identified and easily monitored.

Watch:

Communities should use drones to monitor forests

The low cost and ease of operating a drone means forests could be measured far more frequently, too, than with conventional—more costly—remote-sensing technologies.

And because they fly beneath the clouds, assessments can be carried out all year, even in the rainy season, enabling year-round monitoring of tropical forests.

In medium to large-sized territories—hundreds to several thousand hectares—the ability to survey all the community territory in just a few flights would make combining drones and ground surveys more cost-effective than ground surveys alone, the study found.

The set-up costs are relatively low, too—within reach of groups of communities or local organizations.

“The price is dropping very rapidly,” McCall said. “You can build your own for under US$2,000; you can even use a 3D printer to print a drone!”

“The camera equipment is still expensive, but some people are working on just using a regular digital camera, taking many, many photos—with the right [open-source] software you can put them together and build up a sufficient image from that,” he said.

NOT ALL ROSY

But there are disadvantages to drones, too, as the study points out.

Small drones are constrained in the amount of equipment they can carry. This limits the quality of the imaging sensors that can be attached, as well as the size of the batteries on board, which tends to reduce flight time to under an hour.

They also are susceptible to being buffeted by the weather, which can introduce distortions in the measurements—meaning they may not be suitable for scientific measurements that require high accuracy. But the study points out the technical capabilities are rapidly improving.

Security issues are a concern, especially in countries like Mexico, where the study’s authors are based.

Operating the drones in forests where illegal logging, poaching, illegal drug production, or military activities are taking place may pose threats to the drone operators, other community members, or partner organizations, the study found.

“In Mexico, a particular issue is with the narco-gangs who certainly will not like these things flying over them,” McCall said.

“The first thing Mexicans say when we say we’re thinking of doing this is, ‘Someone will shoot it down,’ ” he said. “But they’re also likely to shoot somebody walking in to measure a forest—and at least it’s only a drone.”

Key to community monitoring?

New technologies

That means security and safety issues must be prioritized by NGOs seeking to use this technology.

“There will have be very clear protocols which are understood by the community, made by the community, and imposed by the community to say what the drones can do, what they can’t do—and who owns the information,” McCall said.

The paper also highlights ethical issues with introducing drones into forest communities—most importantly, concerns about privacy. Drones could spark conflict and accusations of privacy violations and spying, the study says.

And there is a risk that their introduction could create tension between and within communities—so the potential advantages and disadvantages should be assessed on a case-by-case basis, McCall said.

“We would never pretend all communities and all forests would be the right place to do this. But it will be useful particularly in communities which have a small population, and a large area,” he said.

WHAT’S IN IT FOR THE VILLAGE?

Why would communities want to take on something like this?

“They’re probably not interested in measuring carbon, directly, but they are interested in the state of their forest,” McCall said.

McCall says even if drones are introduced for carbon-monitoring purposes, communities would need to be allowed to use them for their own purposes, as well—and there are plenty of potential applications.

“The drone will give them an eye in the sky to see what’s going on,” he said.

They could monitor invasions of their territory more safely; check for tree diseases and pests; and more quickly tackle fires.

Watch:

Survey highlights REDD+ controversies

“We work in some communities in Northern Mexico which are very extensive—up to 20 or 30 kilometers across,” McCall said.

“From fire towers, they can see a wildfire in the distance, and if they jump in a truck, they can get there in an hour. With a drone, they could be there in five minutes, take pictures showing which direction the fire is going, how fast it’s growing—and send the information back immediately.”

What’s most important, he said, is that those who are interested get started now, rather than later.

“The technology is ready for it, communities are ready for it; what is going to change very soon is the legislation,” he said.

“In 10 years’ time, drones will be ubiquitous, and probably be seen as a pest around the world—they’re a little bit noisy, and there could be accidents, they could crash or be misused by people.”

Before long, drones are likely to be banned in many places, and the window of opportunity for their responsible use in community forest monitoring could close, McCall said.

“I believe if we start now and show that drones can have some social benefits for groups of society who are relatively worse off, then this could be an argument for legislation to make some exceptions,” he said.