Chu (river)

The Chu is formed by the confluence of the rivers Joon Aryk and Kochkor, ==History==

The area of this river was originally home to the Iranian Sughds who spoke Soghdian, an Eastern Iranian language. During the Middle Ages, the area was strategically important. It was the setting of Suyab, the capital of the Western Turkic Khaganate and Balasagun, the capital of the Qara Khitai (Western Liao dynasty). The Chu River posed a risk of flooding for settlements located in the Chu Valley. In the winter of 1878, an ice gorge formed on the Chu River upstream from Tokmok, the administrative centre of Semirechye Province. This was followed by severe flooding that damaged the town and the province's capital was moved to Pishpek (Bishkek). ==Dams==

The river flow is regulated by the dam at Orto-Tokoy Reservoir in Kyrgyzstan built in 1957 and the dam at Tasotkel Reservoir in Kazakhstan built in 1974. ==Ecology and environment==

Environmental monitoring The Kyrgyz State Agency for Hydrometeorology and the Kazakhstan Hydrometeorological Service (Kazhydromet) operate a number of water quality monitoring stations on the Chu River and its tributaries. Water quality According to the Kyrgyz State Agency for Hydrometeorology, in 2004–08 the water pollution index of the Chu River in the Chu Valley ranged from 0.25 to 0.7 units, which is interpreted as Class II ("Clean water"). The only exception was a monitoring point downstream of Vasilyevka village where the water pollution index ranged from 0.4 to 1.2 units and water quality was assessed as Class II(Clean)/Class III ("Moderately polluted"). ==Major tributaries==

In Kyrgyzstan, 4892 rivers and canals flow into Chu River. The main tributaries are, from source to mouth: • Kochkor (left) • Joon Aryk (right) • Chong-Kemin (right) • Kichi-Kemin (right) • Kara-Konguz (right) • Shamshy (left) • Ysyk-Ata (left) • Alamüdün (left) • Ala-Archa (left) • Jylamysh (left) • Kakpatas (right) • Ak-Suu (left) • Kuragaty (left) ==Gallery==

Image:E8145-Chu-River.jpg|In the Boom Gorge Image:balbal.jpg|A medieval balbal near Burana Tower in the Chüy Valley Image:E8046-Chuy-Valley-Milyanfan-east.jpg|In the Chüy Valley near Milyanfan Image:E7858-Korday-Chu.jpg|Near Korday border crossing Image:E7840-Shu-city-river-crossing.jpg|Near Shu, Kazakhstan ==See also==