Lake Balkhash is one of the largest
lakes in Asia and 15th largest in the world. It is in the east of Central Asia
in southeastern Kazakhstan and sits in an endorheic (closed) basin. The basin
drains seven rivers, the primary of which is the Ili, bringing most of the
riparian inflow; others, such as the Karatal, bring surface and subsurface
flow. The Ili is fed by precipitation, largely vernal snowmelt, from the
mountains of China's Xinjiang region.
The lake currently covers about
16,400 km2 (6,300 sq mi). However, like the Aral Sea, it is shrinking due to
diversion and extraction of water from its feeders. The lake has a narrow,
quite central, strait. The lake's western part is fresh water. The lake's
eastern half is saline. The east is on average 1.7 times deeper than the west.
The largest shore city is named Balkhash and has about 66,000 inhabitants. Main
local economic activities include mining, ore processing and fishing.
There is concern about the lake's
shallowing due to desertification of microclimates and water extraction for
multiplied industrial output. The present name of the lake originates from the
word "balkas" of Tatar, Kazakh and Southern Altai languages which
means "tussocks in a swamp".
The lake covers about 16,400 km2
(2000), making it the largest lake wholly in Kazakhstan. Its surface is about
340 m above sea level. It has a gentle curve (sickle) shape yet with jagged
shorelines. Its length is about 600 km and the width varies from 9–19 km in the
eastern part to 74 km in the western part. Saryesik Peninsula, near the middle
of the lake, hydrographically divides it into two very different parts. The
western part, which covers 58%, but 46% of the volume. It is thus relatively
shallow, quiet and is filled with freshwater. The eastern part is much deeper
and saltier. These parts are connected by the Uzynaral Strait 3.5 km wide and
about 6 metres deep.
The lake includes several small
basins. In the western part, are two depressions 7–11 meters deep. One extends
from the western coast (near Tasaral Island) to Cape Korzhyntubek, whereas the
second lies south from the Gulf Bertys, which is the deepest part of the "half".
The average depth of the eastern basin is 16 m and has the maximum depth (of 26
m).
The average depth of the lake is 5.8
metres, and the total volume of water is about 112 km3. The western and
northern shores of the lake are high (20–30 m) and rocky; they are composed of
such Paleozoic rocks as porphyry, tuff, granite, schist and limestone and keep
traces of ancient terraces. The southern shores near the Gulf Karashagan and
Ili River are low (1–2 m) and sandy. They are often flooded and therefore contain
numerous water pools. Occasional hills are present with the height of 5–10 m.
The coastline is very curvy and dissected by numerous bays and coves. The large
bays of the western part are: Saryshagan, Kashkanteniz, Karakamys, Shempek (the
southern pole of the lake), and Balakashkan Ahmetsu, and those in the eastern
part are: Guzkol, Balyktykol, Kukuna, Karashigan. The eastern part also
includes peninsulas Baygabyl, Balay, Shaukar, Kentubek and Korzhintobe.
The lake contains 43 islands with a
total area of 66 km2; however, new islands are being formed due to the lowering
of water level, and the area of the existing ones is increasing. The islands of
the western part include Tasaral and Basaral (the largest), as well as
Ortaaral, Ayakaral and Olzhabekaral. The eastern islands include Ozynaral,
Ultarakty, Korzhyn and Algazy.
Sources :
https://en.wikipedia.org/wiki/Lake_Balkhash
https://earthobservatory.nasa.gov/images/91230/lake-balkhash
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