Usually floods of this magnitude occur in southern Bangladesh and are caused by storms washing seawater over coastal regions. This year, however, unrelenting torrential rains across the entire eastern sub-continent gave rise to the deluge. The massive amounts of rainwater that fell on Nepal and Assam drained into an already waterlogged eastern Bangladesh. Normally, the Brahmaputra River and its tributaries would resemble a tangle of thin lines, and the large black patches in Bangladesh would be tan.
In this false-color image, land is tan, and clouds are pink and white. Water comes across as black or dark brown.