One Kazakh lake is fresh on one side, salty on the other
Lake Balkhash covers about 16,400 square kilometres in southeastern Kazakhstan—Asia’s great sickle-shaped endorheic basin and the world’s fifteenth-largest lake. A narrow strait splits a fresher west from a saltier east while rivers enter and none leave.
Sitting near 340 metres elevation in the Balkhash-Alakol depression, the lake stretches roughly 600 kilometres yet averages only 5.8 metres deep, holding about 112 cubic kilometres of water. Forty-three islands total 66 square kilometres and keep growing as levels fall. Tasaral and Basaral are the biggest of them, both in the western half. The Ili River supplies 73–80 percent of inflow; Aksu and Karatal add glacier-fed volumes from the Tian Shan and beyond. The Tokrau descends from the north but vanishes into sand before it ever reaches the shore. In 1910 the surface neared 23,464 square kilometres before shrinking toward 15,730 by 1946.
The Saryesik peninsula, whose Kazakh name means Yellow Door, pinches the lake in two, leaving only the Uzynaral strait to join the halves. Long ago Alakol, Sasykkol and other nearby lakes were part of a far larger Balkhash, and earlier still a sea reached as far as the Dzungarian Alatau. The whole Balkhash-Alakol basin spans about 512,000 square kilometres and yields some 27.76 cubic kilometres of runoff a year, of which 11.5 flows in from China.
The name traces to Turkic balkas—“tussocks in a swamp.” Chinese records knew Yibohai for centuries; after 1759 the shore marked Qing’s northwestern limit until the 1864 transfer to Russia. From as early as 103 BCE the Chinese called the polity around the lake Bugu or Busu, and from the eighth century the land between the lake and the Tian Shan was known in Turkic as Jetisu, Seven Rivers, where steppe nomads mingled with settled peoples. Kapshagay Reservoir’s filling pushed a modern low of 340.65 metres in 1987 before rains lifted levels to 342.5 metres by January 2005.
Desertification, upstream diversion, and climate stress now echo Aral Sea warnings. The west and north are walled by cliffs 20 to 30 metres high of porphyry, tuff, granite and limestone, while the southern margin near the Ili and Karashagan Gulf rises only a metre or two.
Source: Lake Balkhash
