Casamance (river)
Casamance | ||
The Casamance at Ziguinchor |
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Data | ||
location |
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River system | Casamance | |
Headwaters | west of Oaba Mamadou and north of Saré Boido Mali 13 ° 9 ′ 35 ″ N , 14 ° 19 ′ 25 ″ W |
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Source height | approx. 45 m | |
muzzle |
Atlantic Ocean Coordinates: 12 ° 33 '22 " N , 16 ° 45' 44" W 12 ° 33 '22 " N , 16 ° 45' 44" W. |
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Mouth height | 0 m | |
Height difference | approx. 45 m | |
Bottom slope | approx. 0.13 ‰ | |
length | 350 km | |
Catchment area | 20,150 km² | |
Navigable | 160 km |
The Casamance is a river in the African state of Senegal . The southern Senegalese area between the states of Gambia and Guinea-Bissau is traditionally referred to as the Casamance , as the Casamance River is the largest and most important body of water in this region.
geography
The headwaters of the river can be found east of Kolda on the northwestern edge of the Vélingara crater and begins as an intermittent body of water , the bed of which only fills with water in the rainy season . It flows in a general westward direction with a valley path of 350 kilometers to the Atlantic Ocean . The river touches the cities of Kolda, Sédhiou and Ziguinchor , the largest city in Casamance.
In the lower reaches, east of Sédhiou to the mouth, the tidal current is noticeable due to the slight gradient over a length of 200 kilometers . Here the river bed has been washed out to a width of 4000 meters. The shore zone is accompanied by a mangrove system that branches out further and further towards the estuary, some bolongs sometimes extend 20 or 30 kilometers into the interior, such as the Kamobeul Bôlon or the Marigot de Diouloulou .
The most important tributary is the Soungrougrou , which joins from the right and north 27 kilometers east of Ziguinchor.
traffic
The Casamane is navigable from Sédhiou. The city of Ziguinchor, 60 kilometers from the sea, has a seaport . Downstream from Kolda to Ziguinchor, the river can only be crossed by ferry, with the exception of a 1250 meter long bridge dam at Diana Malari in the Sédhiou region . The 650-meter-long pont Émile Badiane has spanned the river near Ziguinchor since the 1970s and connects the city on the south bank with Bignona and the greater part of the Ziguinchor region and with Gambia.
Salinity
Since the Casamance receives practically no water from the catchment area outside of the rainy season, the strong evaporation during the dry season leads to negative runoff. The water evaporating in the middle and lower reaches is replenished from the Atlantic. As a result, salt water is sometimes kept in the river bed for years and concentrated to over 100 g / l. There are times when areas of the river are almost inanimate due to the high salinity.
Individual evidence
- ↑ OpenTopoMap
- ^ Service Régional de la Statistique et de la Démographie de Ziguinchor: Situation economique et sociale regional 2013 Length and catchment area according to page 11 of the PDF file 3.63 MB
- ↑ Measure distances with google maps
- ↑ Kamobeul Bôlon at Geonames
- ^ Marigot de Diouloulou at Geonames
- ↑ Eiffage Sénégal: Réhabilitation du pont à Émile Badiane Ziguinchor
- ↑ Ecological zonation of the hyperhaline estuary of the Casamance River (Senegal): Foraminifera, zooplankton and abiotic variables article in Hydrobiologia of April 1989