Seemingly barren areas, in Western Sahara and the Sahel, have revealed something surprising. Satellite images found that around 1.8 billion trees are growing in the region.
According to the professor of geography at the University of Copenhagen and lead author of the research, Martin Brandt, there are certainly vast areas without trees, but among the sand dunes you can see some trees growing.
The research provides researchers with data that can help guide efforts to combat deforestation.
“For preservation, restoration, climate change and so on, data like this is very important for establishing a baseline,” says Jesse Meyer, a programmer at NASA’s Goddard Space Flight Centre who worked on the research. “In a year, two or ten years, the study can be repeated to see whether efforts to revitalize and reduce deforestation have been effective or not,” he said in a NASA press release.
In more wooded areas they appear more clearly on satellite images, even at low resolution, and are easily distinguishable. But in regions where the green is reduced, satellite images may have difficulties in detecting individual trees or even in small groups.
Even with the availability of high-resolution images, counting individual trees, especially in vast areas of the territory, is an almost impossible task. So, Brandt and his team found a solution. They are using a computer program with Deep Learning to do the job for them.
The research, published in the journal Nature, covered an area of 1.3 million square kilometres and analysed more than 11,000 images.
The technique suggests that in the future it will be possible to map the location and size of each tree worldwide. This would help to determine how much carbon is being stored in these locations. But for now, it is too early to say whether an accurate count of each tree’s life will affect how we understand climate change and its acceleration, according to Brandt. What he wants now is to use the technique elsewhere, to map more trees.