Earth from Space: Ganges' dazzling delta
This Envisat image highlights the Ganges Delta, the world’s largest delta, in the south Asia area of Bangladesh (visible) and India. The delta plain, about 350-km wide along the Bay of Bengal, is formed by the confluence of the rivers Ganges, the Brahmaputra and Meghna.
The world’s largest mangrove forest, the Sundarbans, is located where the land meets the water. The Sundarbans forest spans Bangladesh and India, with each country’s forest listed as a UNESCO World Heritage site. The Sundarbans, which translates as 'beautiful forest' in Bengali, provide critical habitat for numerous species, including the Bengal tiger and the estuarine crocodile.
Pollution, human encroachment, soil erosion and rising sea levels threaten to submerge large parts of the forest into the sea. In the past two decades, four mangrove islands have sunk and more are threatened.
Southern Bangladesh is hit every year by cyclones and floods. In May this year, cyclone Aila formed in the Bay of Bengal and thrashed Bangladesh’s southwestern coast, with the Sundarbans withstanding the worst. In November 2007, cyclone Sidr hit the country's southwestern coast, leaving more than 4000 people dead or missing.
The annual delta flooding leaves behind rich alluvial deposits, which are used to grow jute, the country’s main cash crop.
As radar images represent surface backscatter rather than reflected light, there is no colour in a standard radar image. This image was created by combining three Envisat Advanced Synthetic Aperture Radar acquisitions (20 January 2009, 24 February 2009 and 31 March 2009) taken over the same area. The colours in the image result from variations in the surface that occurred between acquisitions.