File:Uttarakhand disaster, India.jpg

English: A devastating flash flood that happened on 7 February 2021 in India's northern state of Uttarakhand caused the deaths of at least 32 people, while several hundred workers of the two hydropower plants construction sites that were destroyed on the rivers Rishi Ganga and Dhauli Ganga are reported missing. The Chamoli district has suffered the brunt of the flood, with massive infrastructural damage, loss of life and widespread environmental damage in the ecologically fragile area of Uttarakhand that lies on the southern slope of the Himalaya range. Relief efforts are still underway, with emergency crews attempting to rescue workers trapped in underground service tunnels and the inhabitants of nearby villages whose houses were washed away by the flood. The exact cause of the devastating flood is yet to be ascertained, but early assessments indicate that the event could have started by a landslide that caused a large avalanche of ice and rock between two remote glacier peaks, Raunthi and Mrigthuni, both at above 5,500 metres of elevation. The role of climate change and climate-related factors has not yet been confirmed, but what is clear is that this was not the first recorded avalanche in this region, as a similar but smaller event was recorded in 2016. This image, which has been acquired by one of the two satellites of the Copernicus Sentinel-2 mission, shows a wide three-dimensional view of the zone most affected by the massive flood. The red arrow on the left shows the possible point of origin of the landslide, and the insert on the right is a magnified view of the sites of the two hydropower plants in construction that were destroyed, the Tapovan Vishnugad Hydropower Project (TVHPP) and the Rishiganga Hydroelectric Project (RGHEP). The Copernicus Sentinel-2 mission is composed of two twin satellites (Sentinel-2A and Sentinel-2B) that provide multispectral data at a maximum spatial resolution of ten metres. Its high-resolution open data allow us to develop an accurate understanding of the extent of the flood and contribute to damage assessment in the affected areas.