Northern Aral Sea
| Northern Aral Sea | ||
|---|---|---|
| Sunrise over the northern Aral Sea | ||
| Geographical location | Kazakhstan | |
| Tributaries | Syr Darya | |
| Drain | Syr Darya through Kokaral Dam | |
| Location close to the shore | Aral | |
| Data | ||
| Coordinates | 46 ° 30 ′ 0 ″ N , 60 ° 42 ′ 0 ″ E | |
|
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| Altitude above sea level |
30 (2003) 42 (2008) |
|
| surface | 2,550 km² (2003) 3,105 km² (2007) 3,300 km² (2008) |
|
| volume | approx. 27 km³ (2007) | |
| Maximum depth | 18 m (2007) | |
| Middle deep | 8.7 m (2007) | |
The Northern Aral Sea ( Kazakh Солтүстік Арал теңізі , Soltüstik Aral teñizi; Russian Северное Аральское море ), and Small Aral (russ. Малое Аральское море ), the part of the former Aral Sea in Kazakhstan , the flow through the Syrdarja is fed. Its outflow is regulated by the Kokaral Dam .
Emergence
To save at least the northern part of the Aral Sea, a dike was built by Kazakhstan in the 1990s to hold back the water. During its existence, the water level rose, the climate improved and more fish could be caught again. However, due to the inadequate construction, this dam broke after a short time. As a result, construction of the Kokaral Dam began in 2003 . Since the World Bank also provided funds for this, this time concrete could be used as a building material. In addition to the construction of this dam, measures have also been taken to improve the irrigation systems of the Syr Darya, which flows into the lake. Sewers were repaired and in some cases also concreted out. This should lead additional water into the lake. In 2005 the Kokaral Dam was completed.
development
By 2006 the lake level rose by 3 meters, the area increased by 900 km², the volume increased by 11 km³ and the salinity fell significantly. In 2008 the water level reached 42 meters and the area reached 3300 km². In some places, the coastline has shifted more than 75 kilometers. The Kazakh government hopes that the lake will largely recover through further improvements to the irrigation systems. Since the lake has a drain, the concentration of toxins also decreased. As a result, fishery yields increased and dust pollution decreased significantly. The fish population, in 2005 only 3,500 tons, had recovered to 18,000 tons by 2012. With a sustainable fisheries policy, the aim is to increase the fish stocks in the northern Aral Sea to up to 40,000 tons.
planning
Within the SYNAS-II (SyrDarya Control and Northern Aral Sea Project Phase II) project , the aim is to damming the Saryschiganak Bay in the northeastern part of the lake to a height of up to 53 m using a second dam and an additional supply channel to the north of the Syrdarja enlarge it further with a second level and extend the lake back to Aralsk .
This would also require the construction of a canal that carries the waters of the Syr Darya into this northern part. This would also flow through the entire lake and promote the exchange with the less salty water of the Syrdarya.
Variants see two main options here: on the one hand, the creation of a 10-kilometer canal from Lake Kamystybas, located in the Syr Darya delta, to the natural depression east of Aralsk, and a forwarding along the natural slope via Aralsk to the northern Aral Sea through which this depression would flow through again for the first time since the Schalkartengis dried up in the 16th century. The other possibility would be the creation of a somewhat longer canal, also largely along the natural gradient, starting from Äiteke Bi ( Novokasalinsk until 1996, 90 km downstream from Baikonur ), whereby a large part of the water evaporating in the Syr Darya inland delta "saved" for the Aral Sea could be.
Web links
- The Kazakh Miracle: Recovery of the North Aral Sea . Environment News Service (ENS), August 1, 2008.
- The rehabilitation of the ecosystem and bioproductivity of the Aral Sea under conditions of water scarcity . International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), August 2007.
Individual evidence
- ↑ a b c Northern Aral Sea recovering: Kazakhstan plans second phase of project . Nature , April 12, 2007.
- ↑ Return of the fish. In: NZZ
- ↑ Scientific investigation of the gravimetric separation of fresh water and salt water in salt lakes. University of Karlsruhe, Institute for Water and Water Development, January 31, 2010, accessed on July 3, 2018 .