Lake Balkhash

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Lake Balkhash
Lake Balkhash - From space, April 1991
From space, April 1991
Location Kazakhstan
Coordinates 45°4′N 76°2′ECoordinates: 45°4′N 76°2′E
Lake type Endorheic
Saline
Primary sources Ili River
Karatal River
Aksu River
Lepsi River
Byan River
Kapal River
Koksu River
Primary outflows evaporation
Catchment area 413,000 km²
Basin countries Kazakhstan 85%
China 15%
Max length 605 km
Max width East 74 km
West 19 km
Surface area 16,996 km²
Average depth 5.8 m
Max depth 25.6 m
Water volume 106 km³
Shore length1 2,385 km
Surface elevation 341.4 m
1 Shore length is an imprecise measure which may not be standardized for this article.

Lake Balkhash (Kazakh: Balqash Köli) is a lake in southeastern Kazakhstan, the second largest in Central Asia after the Aral Sea. It is a closed basin that is part of the endorheic basin that includes the Caspian and Aral seas.

Contents

[edit] History

From as early as 103 BC up until the 8th century, the Balkhash polity was known to the Chinese as Pu-Ku/Bu-Ku. From the 8th century the land to the south of the lake, between it and the Tian Shan mountains, was known as "Seven Rivers" (Jetisu in Turkic, Semirechye in Russian). It was a land where the nomadic Turks and Mongols of the steppe mingled cultures with the settled peoples of Central Asia.[1] During China's Qing Dynasty (1644 - 1911), the lake formed the northwestern-most boundary of the Empire. However, in 1864, the lake and its neighbouring area was ceded to Imperial Russia through what Chinese histories call an unequal treaty, the Sino-Russian Treaty on the Northwestern Boundary. With the dissolution of the Soviet Union in 1991, the lake became part of Kazakhstan.

[edit] Characteristics

Lake Balkhash: NASA image, taken 18 April 2000 by SeaWiFS
Lake Balkhash: NASA image, taken 18 April 2000 by SeaWiFS

The lake currently covers 16,996 km² (6,562 sq mi), but, like the Aral Sea, it is shrinking because of the diversion of water from the rivers that feed it.[2] The lake has a mean depth of 5.8 m, and a maximum of 25.6 m. The western half of the lake is fresh water, while the eastern half is saline.[3] The mean depth of the eastern part is 1.7 times that of the western. Approximately 1600 km to the northeast lies Lake Baikal, the largest lake on Earth by volume.

The Balkhash inland basin drains into Lake Balkhash via seven rivers; chief among these is the Ili River, which brings the majority of the riparian inflow, others such as the Karatal provide both surface and subsurface flow. The Ili is fed from precipitation (largely vernal snowmelt) from the mountains of China's Xinjiang region. The Balkhash basin is itself endorheic – there is no outflow – and Balkhash suffers from the same problems as other endorheic lakes.

[edit] Economic development

The waters of the Ili River and of Lake Balkhash are of vital economic importance to Kazakhstan. The Ili is dammed for hydroelectric power at Kaptchagayskoye, and the river waters are heavily diverted for agricultural irrigation and for industrial purposes. Balkhash itself serves as a vital fishery.

[edit] Environmental and political problems

As the population and degree of industrialisation in western China increase, and with traditionally poor political relations between Kazakhstan and the People's Republic, it is likely that conflict over the fate of the limited waters of the Ili will intensify. Similar international disputes over water use in the arid region led to the desiccation of the Aral Sea, and Balkhash appears to be following a similar path.[4]

The water pollution of Balkhash is intensified as urbanisation and industrialisation in the area grow rapidly. Extinctions of species in the lake due to its decreasing area, as well as overfishing activities, are cause for alarm among conservationist organisations worldwide.[5]

[edit] External links

[edit] References

  1. ^ Soucek, Svat (2000) A History of Inner Asia, Princeton: Cambridge University Press, p. 22.
  2. ^ http://www.ilec.or.jp/database/asi/asi-54.html
  3. ^ Kawabata, Yoshiko et al. (March 1997) "The phytoplankton of some saline lakes in Central Asia" International Journal of Salt Lake Research 6(1): pp. 5-16;
  4. ^ http://news.bbc.co.uk/1/hi/world/asia-pacific/3397077.stm
  5. ^ http://www.iucn.org/themes/wani/eatlas/html/as4.html