September 21, 2009
Sinking deltas threaten millions of lives
deltas are sinking, increasing the flood risk faced by hundreds of millions of people, scientists report.
Damming and diverting rivers means that much less sediment now reaches many delta areas, while extraction of gas and groundwater also lowers the land.
Rivers affected include the Colorado, Nile, Pearl, Rhone and Yangtze.
About half a billion people live in these regions, the researchers note in the journal Nature Geoscience.
They calculate that 85% of major deltas have seen severe flooding in recent years, and that the area of land vulnerable to flooding will increase by about 50% in the next 40 years as land sinks and climate change causes sea levels to rise.
Lena river delta (NASA)
Most of the world’s major river deltas are sinking, increasing the flood risk faced by hundreds of millions of people, scientists report.
Damming and diverting rivers means that much less sediment now reaches many delta areas, while extraction of gas and groundwater also lowers the land.
Rivers affected include the Colorado, Nile, Pearl, Rhone and Yangtze.
About half a billion people live in these regions, the researchers note in the journal Nature Geoscience.
They calculate that 85% of major deltas have seen severe flooding in recent years, and that the area of land vulnerable to flooding will increase by about 50% in the next 40 years as land sinks and climate change causes sea levels to rise.
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