Lake Victoria

Largest lake in Africa, Beckensee, transformed natural lake

The Victoria (also Victoria, Victoria Nyanza, formerly Ukerewesee ) is located in East Africa and is part of the States Tanzania, Uganda and Kenya. It is the third largest lake in the world. (After the Caspian Sea and Lake Superior ) and the second largest freshwater lake in the world Lake Victoria is thus the largest lake in Africa, he has a catchment area of ​​193,000 km ². It has an area of ​​68,800 km ², which corresponds approximately to the area of Bavaria or Ireland. On its shores in 2007 lived about 30 million people.

Geography

The lake is located in the East African highlands. The area of ​​the lake sharing the States Tanzania (49% of lake area ), Uganda (45%) and Kenya ( 6%). Its coastline has a length of 3450 km, of which 1750 km on Tanzania, Uganda, and 1150 km to 550 km on Kenya.

While Victoria is fed to the west by the Kagera River Nile, its drain is located in the north - this is the Victoria Nile (hence the lake is considered to be the source, but not as the source of the Nile ). The largest island is 560 km ² Ukerewe before the South Shore. Long stretches of his bank are lined by extensive papyrus swamps.

The region around Lake Victoria is relatively high precipitation and is indicated with an average of 1015 mm per year. 85 % of the lake water receives the Victoria of rainfall, 15 % of inflows (among the rivers Kagera, Nzoia, Sio and Yala ). The evaporation is high and equal to 85 % of the effluent from the lake water.

From natural lake to the reservoir

The reservoir volume is 204.8 cubic kilometers and its total volume of 2760 km ³. His former natural size, however, was artificially enlarged by the construction of the Owen Falls Dam, which was completed in Jinja at the Victoria Nile in 1954, so that the natural lake of the water of the reservoir thereby incurred - was flooded - " Victoria reservoir " called. Since then, the somewhat north of its former northern shore are previously exposed Owen and flooded Ripon Falls. Various claims to the lake whose water surface is at full back in 1134 meters height is a maximum of 81 meters or 85 feet deep and 45 feet deep on average.

Once in 2002, Uganda had taken a second hydropower plant in this area in operation, the water level of the lake reached a record low, as measured for the last time 80 years ago in 2006.

Lake Victoria is geologically a very young lake, its age is estimated to be less than a million years. 14,700 years ago, he is the last time completely dried up. He has to exhibit an amazing diversity of species. Among the tributaries include the Pindibo and Adabo River ( from Burundi ).

The Victoria was rediscovered in 1858 by British explorer John Hanning Speke in the Western world, according to the then Queen of Great Britain, Victoria, named. 1875 Sir Henry Morton Stanley visited the lake with a boat, where he once completely circled him.

Flora and Fauna

In addition to the hippo there in Lake Victoria about 550 different fish species in twelve families and 28 genera. In contrast, live in Europe just over 200 species of freshwater fish. A large proportion of species richness concerned the tilapia ( cichlid ), the terms of the relatively short time since the last desiccation had an extraordinarily high species richness. This was therefore also a popular object of research in evolutionary biology. For 1970 it was estimated that the cichlid to about 500 until 1995, more than 400 cichlid species have been described in Lake Victoria. Many species were not yet described or had only received provisional name.

Ecological disaster

In the 1960s, the Nile perch (Lates niloticus ) was settled as allochthonous species targeted in Lake Victoria, to grow a commercially exploitable good food fish. While on his rapid multiplication followed the expected recovery of export-oriented fishing industry, but it ended in an unexpected disaster, because the Nile perch for the extinction of most of the cichlid species was responsible and the local dry fish industry ruined. Today, the Nile perch is available as " tilapia " in international fish trade. The background of this development theme of the film Darwin 's Nightmare. However, the Nile perch was decimated by the consistent consumption, what other types of fish fed back is more habitat.

Another problem is also not naturally occurring water hyacinth in Lake Victoria, now overgrown wide areas. 1995 90 % of the Ugandan coastline was covered with this plant. Again, would contribute to a consistent use of ecological relief.

Due to the dense population on its banks of the lake is struggling today with massive environmental problems such as pollution and lack of oxygen. These crises led the Global Nature Fund to declare the Lake Victoria to the " endangered Lake of the Year 2005."

Islands in Lake Victoria

• Migingo
• Pyramid Iceland
• Ukara
• Ukerewe

Literature and Film

• Tijs Goldschmidt: Darwin's Dream Lake. News from my research trip to Africa. C. H. Beck, Munich 1997, ISBN 3-406-42881-9
• Movie: Darwin 's Nightmare, directed by Hubert Sauper, 2005 ( also available on DVD ). The award-winning film documents the environmental and economic disaster at the Victoria in East Africa by exposure of the Nile perch.