Satellite images have revealed the devastating impact of recent flooding in Bangladesh, with two thirds of country submerged in water. Pictures taken by the NASA satellite Aqua on 22 July show water-covering areas of Bangladesh and eastern India.
Three weeks worth of torrential rain have resulted in the worst flooding that the impoverished nation has seen for 15 years. So far, 400 people have been killed by drowning, collapsing buildings and disease resulting from the floods.
The Aqua satellite images were captured using the spacecraft’s Moderate Resolution Imaging Spectroradiometer (MODIS). The instrument provides high resolution images in 36 spectral bands across a range of wavelengths.
In one image produced by MODIS – coloured to show different spectral signatures – vast regions of flooding are shown across Bangladesh. The flooding is shaded as both dark blue and white. Blue represents the spectral signature of water while white represents light from the Sun reflected by ground water.
Bangladesh normally experiences heavy flooding during the monsoon season, and around 20 per cent of the low-lying country is submerged annually.
The Asian monsoon season is generated by an annual weather change in southern Asia that heats large areas of land mass. Because ocean regions remain much cooler, the temperature difference forces cool, moist air to rush inland, bringing with it torrential rains. However, the distribution of these rains is always different.
Across Bangladesh about 20 million people have reportedly been displaced by the flooding. Agriculture officials say crops worth $380 million have also been ruined.
Throughout southern Asia at least 1000 people are believed to have died as a result of the flooding. This includes 400 people in India’s eastern state of Bihar and 170 people in East Indian state of Assam.