Oti
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Oti Pendjari |
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 The Oti in the Volta catchment area (center, right) |
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| Data | ||
| location |
 Benin Burkina Faso Togo Ghana  
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| River system | Volta | |
| Drain over | Volta → Gulf of Guinea | |
| Headwaters | in the Atakora Mountains in Benin 10 ° 39 ′ 23 " N , 1 ° 28 ′ 39" E |
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| Source height | 640 m | |
| muzzle | south of the village Damanko in the Volta reservoir Coordinates: 8 ° 22 ′ 25 ″ N , 0 ° 7 ′ 15 ″ E 8 ° 22 ′ 25 ″ N , 0 ° 7 ′ 15 ″ E
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| length | 937 km | |
| Catchment area | 72,778 km² | |
| Discharge at the Sabari A Eo gauge: 57,698 km² |
NNQ MNQ 1959–1974 MQ 1959–1974 Mq 1959–1974 MHQ 1959–1974 HHQ (max. Month Ø) |
0 l / s 3.6 m³ / s 298 m³ / s 5.2 l / (s km²) 1894 m³ / s 3040 m³ / s |
| Discharge A Eo : 72,778 km² at the mouth |
MQ Mq |
500 m³ / s 6.9 l / (s km²) |
| Left tributaries | Kumaga ( called Kerang in the upper section ); Toubili , Kara , Mô | |
| Right tributaries | Kourtiagou, Oualé (Koul Podiéga), Doubodo, Singou , Arli | |
| Medium-sized cities | Sansanne mango , mandouri | |
| Small towns | Koumongou, Porga | |
 The Pendjari (or Oti) in the north of Pendjari National Park during the dry season; left bank Benin, right bank Burkina Faso |
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The Oti (or Pendjari ) is a West African river in Benin , Burkina Faso , Togo and Ghana .
geography
The river has its source as Pendjari in the Atakora Mountains in Benin. It initially flows north, but then makes a U-turn to the south-west. The border between Benin and Burkina Faso runs along its course between the 1 ° 52 'W meridian and the border triangle Benin-Togo-Burkina Faso. The river then flows through north Togo between Mandouri and Sansanné-Mango in a south-westerly direction and flows into Ghanaian territory for the first time at 10 ° 16 '18 " N , 0 ° 22' 43" E. It then runs in an almost southerly direction along the Ghanaian-Togolese border, sometimes on Ghanaian, but mostly on Togolese territory. At 9 ° 26 '8 ″ N , 0 ° 14 ′ 38.6 ″ E , it finally changes to Ghanaian territory until it flows into the Volta reservoir south of the village of Damanko, into which it flows at an average of 500 m³ / s pours.
Catchment area
The catchment area of the river extends to four similarly large parts over the neighboring states.
| States | Catchment area of the state in [km²] | Percent of the area of the catchment area | Percent of the country's area |
|---|---|---|---|
| Ghana | 16.801 | 22.4 | 7.0 |
| Togo | 21,572 | 28.7 | 38.0 |
| Burkina Faso | 21,352 | 28.4 | 8.0 |
| Benin | 15,385 | 20.5 | 13.7 |
| total | 72,778 | 100 |
Hydrometry
The flow rate of the river was measured in Sabari at about 2/3 of the catchment area in m³ / s
Water quality
The pH value of the Oti water at its mouth varies between 6.4 and 6.7. The ion content in the water was (1950s): Na + : 3.2 mg / l; K + : 0.22 mg / l; Ca 2+ : 300 mg / l; Mg 2+ : 11.6 mg / l; CO 2 (dissolved): 39 mg / l; Cl - : 23.4 mg / l; SO 4 2− : 96 g / l; SiO 2 : 132 mg / l.
Economical meaning
Importance as a traffic route
The Oti is hardly navigable with boats. When the water is in high water, boat traffic is hindered by a fast current, and numerous rapids are added as traffic obstacles. When the tide is low, sandbanks make it possible to cross the river bed in numerous places, and sometimes it should even be possible to cross the river with dry feet.
Importance for ecotourism
South of the northern Togolese district capital Sansanné-Mango extends from its left bank to the Kéran National Park ( Parc National de la Keran ). In the northeast of the Republic of Togo the Oti flows through the Oti Wildlife Reserve ( La réserve de faune Oti-Mandouri ), which merges into the Pendjari National Park on the Beninese side and into the Arli-W-Singou Complex on the Burkinabe side ( Arly National Park , Réserve partial de l'Arli, Réserve partial de Pama , National Park W , Réserve totale du Singou ).
history
archeology
In the northern Togolese Oti Valley between the district capitals Sansanné-Mango and Mandouri, an archaeological inventory was carried out in 1999/2000 under the direction of the American anthropologist Philip de Barros. One hoped here u. a. also to find sites of the Kintampo culture after some Kintampo finds had been found in the Bassar region further south-east . The existence of such sites in the Oti Valley would have proven that the bearers of the Ghanaian Kintampo culture, coming from the Sahara, would have come through the easily accessible Oti Valley, especially along the White Volta, into which the Oti actually pours, numerous Kintampo sites are known (e.g. at Ntereso, 8 ° 47 ' N , 2 ° 34' W ). However, the result of the investigation was negative with regard to Kintampo. Not a single Kintampo square was found and any finds from earlier times were also unknown to the local farmers. This suggests that if the bearers of the Kintampo culture really came to Ghana from the Sahara, they did not move through the Oti Valley.
Extreme flood
After excessive rainfall in October 1998, extreme floods occurred in early 1999 both in the northern Togolese Oti valley (prefectures Oti and Kpendjal) and in the hinterland of the coast (prefecture Lacs), which left many residents homeless near the river. An assessment committee of the International Red Cross then set the number of people in need at 15,785 people in 18 municipalities in Lacs prefecture, 6530 people in 7 municipalities in Oti prefecture and 8090 people in 27 municipalities in Kpendjal prefecture. In the period 17. – 21. February 1999 on the coast and between February 21 and March 4, 1999 in Oti and Kpendjal, aid goods worth CHF 170,000 (purchase price) were distributed to those in need.
Individual evidence
- ↑ a b c Water Resources Assessment of the Volta River Basin IWMI Working Paper
- ↑ a b GRDC - Sabari gauge
- ↑ The values for calcium and sulfate appear too high.
swell
- J.-P. Vanden Bossche, GM Bernacsek: Source book for the inland fishery resources of Africa: 2.
- CIFA Technical Paper. No. 18.2, Rome, FAO, 1990, pp. 411ff. (on-line)
- Report of the International Red Cross on the Togo flood in 1999 (English; PDF; 10 kB)