Betsiboka River

Betsiboka River is a 525 km long river in central-north Madagascar. It flows northwestward and empties to Bombetoka Bay, forming a large delta. The river is distinct for its red-coloured water, which is caused by river sediments. The river carries an enormous amount of reddish-orange silt to the sea. Much of this silt is deposited at the mouth of the river or in the bay.

It is dramatic evidence of the catastrophic erosion of northwestern Madagascar. Removal of the native forest for cultivation and pastureland during the past 50 years has led to massive annual soil losses approaching 250 metric tonnes per hectare (112 tons per acre) in some regions of the island, the largest amount recorded anywhere in the world.

References

* [http://earthobservatory.nasa.gov/NaturalHazards/shownh.php3?img_id=14135 Floods in Madagascar] at NASA Earth Observatory
* [http://www.lpi.usra.edu/publications/slidesets/geology/sgeo/slide_23.html Sediment Laden Drainages] at Lunar and Planetary Institute, USRA
* [http://eol.jsc.nasa.gov/sseop/EFS/photoinfo.pl?PHOTO=STS007-3-58 NASA: Earth from Space]