Irtysh


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Irtysh

(ĭrtĭsh`), river, c.2,650 mi (4,260 km) long, W Siberian Russia and Kazakhstan. It is the chief tributary of the Ob and one of the two major rivers of W Siberia. As the Ertix, it rises in Xinjiang, China, in the Mongolian Altai Mts., flows NW through Lake Zaysan in Kazakhstan (where it is known as the Ertis), and enters W Siberia. There it receives the Ishim and Tobol rivers, its chief tributaries. The Irtysh flows past Semey in Kazakhstan and Omsk and Tobolsk in Russia and joins the Ob near Khanty-Mansiysk. Major hydroelectric stations are at Öskemen and Zhana Buktyrma, Kazakstan. The river banks were occupied by Chinese, Kalmyks, and Mongols until the Russians arrived in the late 16th cent. The Russian conquest of the basin was completed by the early 19th cent.

Irtysh

 

a river in the Kazakh SSR (Vostochnyi Kazakhstan, Semipalatinsk, and Pavlodar oblasts) and the RSFSR (Omsk and Tiumen’ oblasts); left-bank tributary of the Ob’. Length, 4,248 km. Basin area, 1,643,000 sq km.

The Irtysh rises in China in the Mongolian Altai Mountains and bears the name Chernyi Irtysh until it discharges into Lake Zaisan. In its upper course, as far as the city of Semipalatinsk, it has the features of a plain-and-mountain river. Owing to the construction of the Ust’-Kamenogorsk and the Bukhtarma hydroelectric power plants, the Irtysh has been transformed into large reservoirs up to the city of Ust’-Kamenogorsk; Lake Zaisan has become part of the Bukhtarma Reservoir. Below Ust’-Kamenogorsk the valley of the Irtysh widens. In this section the Kal’dzhir, Kurchum, Narym, Bukhtarma, Ul’ba, and Uba rivers empty into the Irtysh and its reservoirs from the right, and the Kyzylsu and Char enter from the left. Below Semipalatinsk the Irtysh emerges onto the West Siberian Plain and flows northwest amid dry steppes, without receiving any significant affluents as far as Omsk. Undrained land and areas of internal drainage are located here. The channel is unstable: one moment it is very tortuous, the next it divides into branches; it has numerous sandy shoals. Below Omsk the Irtysh forms large meanders. The valley is wide, up to 20 km across and as much as 35 km near the mouth. At the mouth of the Tobol the Irtysh veers sharply north and flows through the most marsh-ridden part of the West Siberian Plain, the channel becoming even more winding. The tributaries here are the Om’ on the right and the Ishim and Tobol on the left.

The Irtysh is fed by various sources: in its upper course by snow and glaciers, and, to a lesser degree, by rain, and in its lower course by snow, rain, and groundwater. The character of its stream-flow regime also changes considerably. In the upper course the high-water period begins in April, the peak water level extends from April to June, and the lowering of the water level lasts until October; the river’s flow is regulated. In the lower course high water lasts from the end of May until September, attaining its maximum level in June. Fifty percent of the annual discharge runs through in the spring; in the upper course the proportion of the discharge in summer and fall is 20 percent in each of these seasons and 10 percent in winter; at Tobol’sk the figures are 27, 19, and 7 percent, respectively. The average discharge (in cu m per sec) is 628 at Ust’-Kamenogorsk, about 960 at Semipalatinsk, 917 at Omsk, and 2,150 at Tobol’sk; at the mouth the annual discharge is approximately 95 cu km. The range of water-level fluctuation above Lake Zaisan is 4.4 m, at Omsk it is 7m, and at Ust’-Ishim it is 12.7 m; the range diminishes toward the mouth. Before becoming icebound the Irtysh has a period of floating ice lasting 20 days in the upper course and six to ten days in the lower course. The Irtysh freezes over in late November in its upper course and in early November in its lower course; ice breaks up in April.

The river is rich in fish—nelma, pike, perch, sturgeon, sterlet, burbot, ide, and bream. The waters of the Irtysh are used to feed the Irtysh-Karaganda Canal (intake of Irtysh water into the canal averaging 75 cu m per second), as a water supply, and for irrigation. There is regular navigation on the Irtysh from the tail water of the Ust’-Kamenogorsk Hydroelectric Power Plant to the mouth. The principal landings are Ust’-Kamenogorsk, Semipalatinsk, Pavlodar, Omsk, Tara, Tobol’sk, and Khanty-Mansiisk.

K. G. TIKHOTSKU

Irtysh

, Irtish
a river in central Asia, rising in China in the Altai Mountains and flowing west through Kazakhstan, then northwest into Russia to join the Ob River as its chief tributary. Length: 4444 km (2760 miles)
References in periodicals archive ?
Other imminent threats could possibly follow: harm to fisheries; contamination of both surface and ground water; disruption of the water balance and natural equilibrium-as the Irtysh feeds Lake Zaisan and the Ili feeds Lake Balkhash both lakes will likely decline; increasing land salinity and degradation of pastures; environmental degradation; deterioration of the epidemiological situation; and last but not least, water shortage.
Floodplain of the Irtysh River in the area of Semey town was chosen as the territory of the research.
Jagiellonia are around evens for victory on their long trip east and given the trouble they had breaking down the Irtysh defence on their own patch that price looks skinny.
A number of environmental problems in the basins of major cross-border rivers such as Irtysh and Ili have accumulated in recent decades.
He argued that a political solution to the Irtysh River dispute was not feasible, since the Chinese did not wish to negotiate (64).
LeDonne describes the 1714 expeditions of Bukhgolts and Cherkassi to Irtysh and Khiva, the 1716 expedition to Copenhagen, and the 1722-23 operations in the Transcaucasus as examples of these deep strategic penetrations.
The largest parasite-endemic area is in western Siberia, namely the Ob and Irtysh River valleys and their tributaries (9-12).
As reported in New Scientist, their plan--a revived Soviet scheme to divert water from the Ob and Irtysh rivers to the Aral region via a 2,500-kilometer canal--would channel the water to cotton plantations in arid Kazakhstan, Turkmenistan, and Uzbekistan.
A truck carrying the beer sank when trying to cross the frozen Irtysh river, and a rescue team of six divers, 10 workers and a modified T-72 tank worked to save the load.
FIRST QUALIFYING ROUND: 1 FC Pyunik (Arm) v KR Reykjavik (Ice); 2 FC Sheriff (Mol) v FC Flora (Est); 3 HB Torshavn (Far) v FBK Kaunas (Lit); 4 FC BATE Borisov (Bls) v Bohemian (Irl); 5 FK Vardar (Mac) v Barry Town (Wal); 6 CS Grevenmacher (Lux) v FK Leotar (Bsh); 7 HJK Helsinki (Fin) v Glentoran (NIrl); 8 Sliema Wanderers (Mlt) v FC Skonto (Lat); 9 Omonia AC (Cyp) v FC Irtysh Pavlodar (Kaz); 10 FC Dinamo Tbilisi (Geo) v KF Tirana (Alb)
This is the amount of water that Soviet planners intended to divert from the Irtysh river in Siberia to Central Asia to save the Aral Sea.
And to round out the bleak picture, he notes China's refusal to cooperate with the downstream states, Kazakhstan and Russia, on the Ili and Irtysh Rivers.