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Africa’s Sahel region stretches between the sands of the Sahara Desert and the rich tropical grasslands of the savanna. Rainfall dominates life in the semi-arid Sahel. The long, hot dry season brings browning grasses and thirst. Between July and September, the rains come to green the land and fill the riverbanks. A good rainy season waters the land deeply enough to allow crops to grow abundantly and it fills lakes and rivers deeply enough to store water for livestock and people to use through the depth of the coming dry season. Sometimes—often—the rains become unending and destructive, dumping so much water that widespread flooding damages homes, fields, and even injures people. For some parts of the West African Sahel, such as the Inner Niger Delta region of Mali, 2020 was a year of exceptional rain and floods.
According to a situation report from the United Nations Office for the Coordination of Humanitarian Affairs (UN OCHA) published on December 2, the rainy season was favorable across most of West Africa, especially the Sahel region. In most areas strongly above average vegetation emerged during September and October. However, exceptionally heavy rainfall during August and September brought severe flooding in many areas, including Mali. The report states that the floods “resulted in fatalities, material damage, destruction of livelihood, population displacements, and deteriorated access. The impact in 2020 is particularly severe, and the number of people affected is almost double from last year” across the flooded areas. The flooding in Mali began in July and by August 6 more than 13,200 people were affected by floods and a total of 1,160 homes had been destroyed. Rains continued through mid-October this year.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired a true-color image of the Inland Niger Delta on December 4, 2020. A spectrum of green shades, ranging from deep emerald to pale Kelly green, mark the river channels, lakes, swamps, and floodplains which have been recently blessed with water. Deep blue marks marks rivers and areas of open water. The burst of color contrasts sharply with the arid tan of the surrounding landscape.
While this image shows an impressive snapshot of the green flood plains of the Inner Niger Delta after the floods, thanks to the NASA Worldview App it is possible to compare the image acquired after the floods with the region prior to the rains. To view a roll-over comparison between two Terra MODIS images of this region, the first acquired on June 1 and the second on December 4, click here.
Image Facts
Satellite:
Terra
Date Acquired: 12/4/2020
Resolutions:
1km (51.2 KB), 500m (172.2 KB), 250m (477.7 KB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC