The Wageningen University & Research (WUR) RAdar for Detecting Deforestation (RADD) alert app is helping to stop illegal logging in African rainforests.
Although it looks like Google Maps, WUR’s RADD isn’t. It’s an alerting system for deforestation. It uses publicly available radar images gathered every six to twelve days by the European Space Agency’s Sentinel-1 satellite. If areas of rainforest disappear, a ‘deforestation alert’ is triggered and it is marked in red. This enables local enforcement agencies to intervene much more quickly and precisely to stop illegal logging.
WUR’s RADD alerting system covers the entire African rainforest, most of which lies within the Congo Basin. This includes the area along the Congo River, which meanders through countries such as the Democratic Republic of the Congo, Gabon, Cameroon and the Central African Republic. The Congo Basin is the second-largest tropical rainforest in the world, after the Amazon. And it is home to countless plant and animal species, some of whom are endangered. But every year at least 800,000 hectares of forest disappear, equivalent to one-fifth of the Netherlands.
“Our alerting system is being used by the Global Forest Watch”, says Johannes Reiche, associate professor of Radar remote sensing. “They’ve been monitoring global deforestation for years and also have excellent partnerships with the governments of tropical countries, as well as with other organisations fighting against deforestation. These include NGOs such as Greenpeace and WWF, but also local stakeholders such as the rangers who protect national parks. The Global Forest Watch app will soon give those rangers access to the RADD alerts too: they’ll be able to see on their mobile phone where areas are in the process of being logged, so they can intervene”.
According to Reiche, existing alerting systems rely mostly on optical images: regular satellite photos of the Earth. “You often wouldn’t see anything on these for months, because there would be thick cloud cover above the African rainforest, particularly during the rainy season. Countries like the Congo and Gabon have some of the heaviest cloud coverage in the world.” This meant that illegal logging used to go unnoticed for months, by which time it was too late to intervene.
“The high-resolution radar images produced by Sentinel-1 allow us to look straight through the clouds, 365 days a year,” explains Reiche. Last year he trialled the RADD system in a smaller region: Indonesia, where rainforest is being cleared for palm oil plantations. Thanks to a collaboration with Global Forest Watch – the international forestry watchdog – and Google (which stores the vast amount of radar satellite data analysed by the alerting system), Reiche’s team at WUR has now been able to scale up to cover the entire African rainforest.
The environmental conservation organisation WWF is delighted with WUR’s RADD alerting system, says its adviser Jorn Dallinga, who is also a WUR alumnus. “We now have a much better idea of where trees are being logged and we can act on that. When all we had was the optical satellite imagery it was often too late to intervene. Now we can swing into action more promptly, and we must do so because deforestation is occurring at a rapid pace in the Congo Basin. The African tropical rainforest is rich in biodiversity and is home to endangered animal species such as the forest elephant and the mountain gorilla. Its peat soils also provide a natural way of capturing CO₂, and releasing it will lead to even greater acceleration in climate change.”
Hence, WWF has moved into making deforestation predictions. The environmental NGO has collaborated with consultancies and technical experts to develop an Early Warning System which is due to be piloted in Gabon in the spring of 2021.
It’s based on the RADD deforestation alerts, combined with around 30 other variables such as the road network (accessibility) and population density. Dallinga says: “By predicting where trees are likely to be logged within the next six months, you can better protect vulnerable areas such as national parks or carbon-rich peatlands from illegal deforestation”.
WWF hopes the pilot in Gabon will optimise the predictive model. Dallinga: “We can already predict 50 per cent of tree felling over the next six months. There’s an 80 per cent certainty that deforestation will occur in those locations.” Eventually, WWF hopes to make the model available to other countries in Africa, such as Congo and Cameroon.
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