Torrential rains caused severe flooding in Sri Lanka in late May 2017. After more than 48 hours of nonstop rain, water levels rose rapidly in the country’s south, spurring emergency evacuations in multiple districts.

On May 28, 2017, the MultiSpectral Instrument (MSI) on the European Space Agency’s Sentinel-2 satellite captured a false-color image of the flood. An earlier image taken on January 29, 2017, by the Operational Land Imager (OLI) on Landsat 8 shows the same area before the waters rose. Both images were made with visible and infrared light (OLI bands 6-5-3 and MSI bands 11-8-3) to distinguish the presence of water on the ground.

Matara was among the hardest hit towns. Low-lying areas around the Nilwala Ganga River (in blue) also have been submerged.

In many areas, flooding has contaminated wells and tainted water supplies. Sri Lankan Foreign Minister Ravi Karunanayake said his country has received medicine and relief supplies from at least a dozen countries, according to reporting by Al Jazeera . Sri Lanka’s Disaster Management Center reported more than half a million people have been affected by the flooding. Search and rescue operations are underway.

NASA Earth Observatory images by Joshua Stevens, using Landsat data from the U.S. Geological Survey and modified Copernicus Sentinel data (2017) processed by the European Space Agency. Story by Pola Lem.