The Online Encyclopedia and Dictionary






Yenisei River

The Yenisei (Енисе́й) is the greatest river system flowing to the Arctic Ocean, slightly shorter but with 1.5 times the flow of the Mississippi-Missouri. Rising in Mongolia, it follows a northerly course to the Kara Sea, draining a large part of central Siberia, the longest stream following the Yenisei-Angara-Selenga being about 5500km.

The upper reaches, subject to rapids and flooding, pass through sparsely populated areas. The middle section is controlled by a series of massive hydroelectric dams fuelling significant Russian primary industry. Partly built by gulag labor in Soviet times, industrial contamination remains a serious problem in an area hard to police. Moving on through sparsely-populated taiga, the Yenisei swells with numerous tributaries and finally reaches the Kara Sea in desolate tundra where it is icebound for more than half the year. As with other Siberian rivers, the flow has increased recently, believed to be due to melting permafrost caused by global warming. A concern is that altered salinity in the Arctic may have a global impact on ocean currents.


Upper Yenisei

The Yenisei rises in two major headstreams: the Bolshoi (greater) Yenisei also known as the Bii-Khem (Бии-Хем) rises in the Tuva region on the S flank of the Eastern Sayan Mountains at 97° 30' E and 52° 20' N; the Malyy (lesser) Yenisei also known as the Kaa-Khem (Каа-Хем) rises in the Darhat (rift) valley in Mongolia. Recent reseach has shown that the narrow exit to the Darhat Valley has regularly been blocked by ice producing a lake as large as neighbouring Lake Khuvsgul. When the glaciers retreated (the last time 9300 years BP) as much as 500 km³ of water would have escaped, possibly catastrophically.

These two headstreams flow west converging at Kyzyl, and on meeting the east-flowing Khemchik River head north through a canyon in the Western Sayan mountains. The Yenisei emerges from the mountains onto an area of steppe where its first control is the 30m dam at Mayna. This section is around 700km.

Lake Baikal Headwaters

The 320km (partly navigable) Upper Angara feeds into the northern end of Lake Baikal from the Buryat Republic but the largest inflow is from the Selenga which forms a delta on the south-eastern side. The longest tributaries rise on the eastern slopes of central Mongolia's Hangayn Nuruu mountains. Another tributary, the Tuul passes through the Mongolian capital, Ulaanbaatar while the Egiin drains Lake Khuvsgul.

This satellite image is 800km across. The green area towards the top-left, containing several small lakes and bordered by the snow-capped Eastern Sayan Mountains to the north, is the source of the Bolshoi Yenisei in Tuva. The dry Darhat Valley just west of Lake Khuvsgul in the center of the image is the source of the Malyy Yenisei. These two streams can be followed to their confluence at Kyzyl at the left of the image.

Lake Baikal is at the right of the image and the Angara flowing north from Irkutsk can clearly be made out. It is already widening due to the dam at Bratsk 200km further north. The Selenga, whose headwaters include Lake Khuvsgul, flows into Lake Baikal in a delta at the extreme edge of the image. The Lena River has its source in the top right of the image

Middle Yenisei

Just downstream from Mayna, the 242m Sayano-Shushenskaya dam at Sayansk powers Russia's largest hydroelectric plant completed in 1989 and producing 6400 MW for aluminium production. This is the same height and five times the power of the Hoover Dam. 100km downstream the Yenisei is swollen by the Abakan river and passes Abakan, capital of the Khakassia region, on the west bank and Minusinsk on the east bank. It passes within 10 km of the Chulym, a tributary of the Ob before reaching Krasnoyarsk after 300km. This halt on the Trans-Siberian railway is the Yenisei's largest city, it is free from ice for around 196 days per year here. The 119m Krasnoyarsk hydroelectric dam, finished in 1964, supplies 6000MW. Krasnoyarsk is a major port (shipping being unable to pass the dam).

70km downstream is the closed city of Zheleznogorsk, a secret Soviet nuclear weapons and satellite facility missing from most maps. The exact state of the enormous nuclear waste dump is unclear, but some discharges continue to pollute the Yenisei. A further 200km downstream comes the confluence with the Angara (whose final section is also known as the Upper [Verkhnyaya] Tunguska).

Angara River

The Angara (Ангара́) river drains Lake Baikal and runs 1840km from the regional capital Irkutsk to converge with the Yenisei at Strelka. It is dammed in four places to power local industry. The 44m dam at Irkutsk produces 650MW. 500km downstream lies Bratsk where the 124m dam built in the 1960s produces 4500MW. The resultant reservoir is nicknamed Dragon Lake on account of its outline. The tributary Oka and Iya rivers, which rise on the north slopes of the Eastern Sayan mountains, form the 'jaws' and 400km of the Angara form the 'tail'. There are newer dams almost as large at Ust-Ilimsk 250km downstream (also damming the tributary Ilim river) and Boguchany a further 400km downstream (not operational). Further dams are planned but the environmental consequences of completely taming the Angara are leading to protests which may prevent funding.

50km downstream of Irkutsk lies Angarsk, the center of the expanding Eastern Siberian oil industry and site of a huge Yukos-owned refinery. A major pipeline takes oil west, and a new one is being built to carry oil east for supply to Japan from the Sea of Japan port of Nakhodka. The exact potential of Eastern Siberia is unknown, but two new major fields are the Kovyktinskoye field near Zhigalovo 200km north of Irkutsk and the extremely remote Verkhnechonskoye field 500km north of Irkutsk on the Central Siberian Plateau

Lower Yenisei

300km downstream of the Strelka the Great Kaz joins the Yenisei, noteworthy for its connection to the Ob via canal and Ket River. The river starts to widen, its bed being littered with islands as numerous rivers augment its flow, in particular 1800km Stony (Podkamennaya) Tunguska, and the 3000km Lower (Nizhnyaya) Tunguska at Turukhansk draining the desolate central Siberian Plateau from the east. The remote Tunguska (Тунгуска) region is most famous for the 1908 meteorite impact, but is now being explored for oil. Beyond Turukhansk, the river enters tundra.

The river is icebound for more than half the year, and if unchecked ice could dam the river causing major flooding. Explosives are used to keep the water flowing. The final town is Dudinka which is connected to Krasnoyarsk by regular passenger boat. The river widens to a 50km estuary for its final 250km and the shipping lanes are kept open by icebreaker.

During the ice age, the route to the arctic was blocked by ice. Though the exact details are unclear, the Yenisei is believed to have flowed into a huge lake filling much of western Siberia, eventually flowing into the Black Sea.

External Links

Last updated: 05-21-2005 05:06:38