Between November 2015 and April 2016, over 36,000 hectare of forest was burnt in the Republic of Congo. The main commercial activity in the area is the extraction of round wood from areas leased from the national authorities by private companies. These cover an extensive part of forest in the north of the country including the Marantaceae forests, which were affected by the fires.
While it is usually too humid for forests to burn in the area, a very strong El Niño caused a high number of fires to spread at the beginning of 2016. During peak times, the fires were spreading as fast as 1,600 hectares a day, making it especially dangerous to track through conventional ways.
The Congolese forests are not only the primary habitat for many large mammals, such as gorillas and forest elephants, but they are also an important carbon storage for the world.
In order to determine the source of the fires and help monitor the spread to better allocate resources to combat and prevention, a consortium, led by the Joint Research Centre used satellite data from both Sentinel-1 and Sentinel-2 — each satellite's sensor compensating for the difficulty of the other (cloud perturbations for Sentinel-2 and sensitivity to ground moisture for Sentinel-1).
"Burnt areas mapped by Sentinel-1's synthetic aperture radar and Sentinel-2's multispectral imagery highlighted that the origin of the fires correlates with accessibility to the forest, suggesting they were caused by human activity.
With a temporal resolution of 10 days and a spatial resolution of 10 m, Sentinel-2A images allow the timing and extent of fire events to be mapped precisely. This is an improvement on the temporal resolution of 16 days and spatial resolution of 30 m that Landsat-8 provides."
Source: Verhegghen et al, 2016