A new tool from Google Earth Engine and the nonprofit World Resources Institute pulls from satellite data to build detailed maps in near real time. Called Dynamic World, it zooms in on the planet in 10-by-10-meter squares from satellite images collected every two to five days. The program uses artificial intelligence to classify each pixel based on nine categories that range from bare ground to trees, crops, and buildings.
Researchers, nonprofits, and other users can “explore and track and monitor changes in these terrestrial ecosystems over time,” says Tanya Birch, senior program manager for Google Earth Outreach. As the tool was being built last year, Birch used it in the days after the Caldor Fire, a wildfire that burned more than 200,000 acres in California. The pixels in satellite images quickly changed from being classified as “trees” to “shrub and scrub.”
Scientists used to rely on statistical tables that were sometimes released only every five years, says Fred Stolle, deputy director of the World Resources Institute’s Forests Program. “That’s clearly not good enough anymore,” he says. “We’re changing so fast, and the impact is so fast, that satellites are now the way to go.”
Researchers and planners already use satellite data in some applications—the World Resources Institute, for example, previously worked with Google to build Global Forest Watch, a tool that can track deforestation using satellite images. But the new data is much more detailed; now it’s sometimes possible to see if one or two trees are cut down in a tropical forest, even when a larger area is intact, Stolle says.
In cities, planners could use the data to easily see which neighborhoods don’t have enough green space. Researchers studying smallholder farms in Africa could use it to see the impacts of drought and when crops are being harvested. Because the data is continuously updated, it’s also possible to watch the seasons change throughout the year across the entire planet. The data goes back five years, and using the new tool, anyone can enter date ranges to see how a location has changed over time.
“I encourage people to dive into it and explore,” Birch says. “There’s a lot of depth and a lot of richness in Dynamic World. . . . I feel like this is really pushing the frontier of mapmaking powered by AI in an incredibly novel way.”