A small wildfire near the town of Vestby broke out on the 13 June 2023. While it was very quickly extinguished on 14 June 2023, its impact could still be seen from space. Using this fire as a simple example, the figure below illustrates how we can determine the area that has been burned by a fire. Using 20 m resolution multispectral images from the Sentinel-2 satellite before and after the fire, a metric called “difference in normalized burn ratio (dNBR)” is derived, which is subsequently used for determining the total area that was burned in the fire. In the case of the Vestby fire this was estimated to be approximately 0.1 km2, a negligibly small area compared to the large wildfire complexes that are typically burning in the fire season in Siberia or Canada.
Determining burned area from Sentinel-2/MSI data. False-color image before the fire (top left), false color image after the fire (top center), difference in normalized burn ratio (top right and bottom left), binary mask of the burned area determined from the difference in normalized burn ratio (bottom center), and vectorized polygon of the burned area derived from the binary mask (bottom right).
