Betsiboka River

Betsiboka River
River
Rapids in the Betsiboka River
Country	Madagascar
Region	Boeny
Tributaries
- left	Ikopa River
- right	Kamoro River
City	Mahajanga, Ambato-Boeny
Source confluence
- elevation	1,755 m (5,758 ft)
Mouth
- location	Bombetoka Bay, Mozambique Channel
- coordinates	15°48′55″S 46°16′13″E / 15.81528°S 46.27028°E / -15.81528; 46.27028
Length	525 km (326 mi)
Volume	74.3 - 678 m3 (-23,869 cu ft)
Basin	11,800 km2 (4,556 sq mi)
Map of Malagasy rivers (Betsiboka flows from the center to the northwestern coast).

Betsiboka River is a 525-kilometre (326 mi) long river in central-north Madagascar. It flows northwestward and empties to Bombetoka Bay, forming a large delta. It originates to the east of Antananarivo. The river is surrounded in mangroves.^[1] 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.^[2] 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. Several fish species are endemic to the river basin, including the three cichlids Paretroplus petiti, P. tsimoly and P. maculatus.

The Betsiboka's largest tributary, the Ikopa River, drains the capital city of Antananarivo.

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  Betsiboka River estuary seen from space

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  The Betsiboka River in normal conditions

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  The Betsiboka River when flooded

References

• Floods in Madagascar at NASA Earth Observatory
• Sediment Laden Drainages at Lunar and Planetary Institute, USRA
• NASA: Earth from Space