
'Western Siberian plain' Seen from the Trans-Siberian railway outside Tatarskaya
The 'West Siberian Plain' () is a large
plain that occupies the western portion of
Siberia in
Russia, between the
Ural Mountains in the west and the
Yenisei River in the east, and by the Eastern
Sayan Mountains and the
Baikal Mountains on the south. It has been described as the world's largest unbroken
lowland—more than 50 percent is less than 330 feet (101 m) above sea level
[1]—and covers an area of about 2.6–2.7 million
km² which is about one third of Siberia,
[2] extending from north to south for 2,400
km, from the
Arctic Ocean to the foothills of the
Altay Mountains, and from west to east for 1,900 km from the
Yenisei River to the
Ural Mountains.
The plain has eight distinct vegetation regions:
tundra, forest-tundra, northern
taiga, middle taiga, southern taiga, sub-taiga forest, forest-steppe, and
steppe. The number of animal species in the West Siberian Plain ranges from at least 107 in the tundra to 278 or more in the forest-steppe region.
Winters on the West Siberian Plain are harsh and long. The climate of most of the plains is either subarctic or continental. Two of the larger cities on the plain are
Surgut and
Nizhnevartovsk.
Geology
The West Siberian Plain consists mostly of
Cenozoic alluvial deposits and is extraordinarily flat. A rise of fifty metres in
sea level would cause all land between the
Arctic Ocean and
Novosibirsk to be inundated (see also
Turgai Straits,
West Siberian Glacial Lake). Many of the deposits on this plain result from ice dams; having reversed the flow of the
Ob and
Yenisei Rivers, redirecting them into the
Caspian Sea, and perhaps the
Aral Sea as well. It is very
swampy and soils are mostly
peaty
Histosols and, in the treeless northern part,
Histels.
It is one of the world's largest areas of peatlands, which are characterized by raised
bogs. It is believed that the world’s largest single raised bog is at Vasuganskoe, covering approximately 51,600 km².
In the south of the plain, where
permafrost is largely absent, rich
grasslands that are an extension of the
Kazakh Steppe formed the original vegetation (almost all cleared now).
Large regions of the plains are flooded in the spring, and
marshlands make much of the area unsuitable for agriculture. The principal rivers in the West Siberian Plain are the Ob,
Irtysh, and Yenisei. There are many lakes and swamps, as well as large
petroleum and
natural gas reserves. Most of the Russia's oil and gas production was extracted from this area during the 1970s and 80s.
See also
★
East European Plain, the other major plain of Russia
Notes
1. Russia
2. Western Siberian Plain
External links
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West Siberian Plain
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Topography and Drainage of Russia
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Peatlands of the Worls: Russia — Siberia