WESTERN SIBERIAN PLAIN, Western Siberian lowland, one of largest plains the globe(the third largest after the Amazonian and East European plains), in the north of Asia, in Russia and Kazakhstan. It occupies the whole of Western Siberia, stretching from the coast of the Arctic Ocean in the north to the Turgai plateau and the Kazakh uplands in the south, from the Urals in the west to the Central Siberian plateau in the east. The length from north to south is up to 2500 km, from west to east from 900 km in (north) to 2000 (in south). The area is about 3 million km 2, including 2.6 million km 2 in Russia. The prevailing heights do not exceed 150 m. The lowest parts of the plain (50–100 m) are located mainly in its central (Kondinskaya and Sredneobskaya lowlands) and northern (Nizhneobskaya, Nadymskaya and Purskaya lowlands) parts. Highest point West Siberian Plain- up to 317 m - located on the Priobsky plateau.

At the base of the West Siberian Plain lies West Siberian platform. To the east it borders on Siberian platform, in the south - with Paleozoic structures of Central Kazakhstan, the Altai-Sayan region, in the west - with the folded system of the Urals.

Relief

The surface is a low accumulative plain with a rather uniform relief (more uniform than that of the East European Plain), the main elements of which are wide flat interfluves and river valleys; characteristic various forms manifestations permafrost(spread up to 59 ° N), increased waterlogging and developed (mainly in the south in loose rocks and soils) ancient and modern salt accumulation. In the north, in the area of ​​​​distribution of marine accumulative and moraine plains (Nadymskaya and Purskaya lowlands), the general flatness of the territory is disturbed by moraine gently sloping and hilly-sloping (North-Sosvinskaya, Lyulimvor, Verkhne-, Srednetazovskaya, etc.) uplands 200–300 m high, the southern boundary of which runs around 61–62 ° N. sh.; they are horseshoe-shaped covered from the south by flat-topped uplands, including the Poluyskaya Upland, Belogorsky Mainland, Tobolsky Mainland, Siberian Uvaly (245 m), etc. In the north, permafrost exogenous processes (thermal erosion, heaving of soils, solifluction) are widespread, deflation is common on sandy surfaces, in swamps - peat accumulation. Permafrost is ubiquitous on the Yamal, Tazovsky, and Gydansky peninsulas; the thickness of the frozen layer is very significant (up to 300–600 m).

To the south, the area of ​​moraine relief is adjoined by flat lacustrine and lacustrine-alluvial lowlands, the lowest (40–80 m high) and swampy of which are the Konda lowland and the Sredneobskaya lowland with the Surgut lowland (105 m high). This area, not covered by the Quaternary glaciation ( south of the line Ivdel - Ishim - Novosibirsk - Tomsk - Krasnoyarsk), is a weakly dissected denudation plain, rising up to 250 m to the west, to the foothills of the Urals. In the interfluve of the Tobol and the Irtysh, there is an inclined, in places with ridges, lacustrine-alluvial Ishim Plain(120–220 m) with a thin cover of loess-like loams and loess occurring on salt-bearing clays. It is adjacent to alluvial Baraba lowland, Vasyugan Plain and Kulunda Plain, where the processes of deflation and modern salt accumulation are developed. In the foothills of Altai - the Ob plateau and the Chulym plain.

On the geological structure and minerals, see Art. West Siberian platform ,

Climate

The West Siberian Plain is dominated by severe, continental climate. The significant length of the territory from north to south determines the well-defined latitudinal zonality of the climate and noticeable differences in the climatic conditions of the northern and southern parts of the plain. The nature of the climate is significantly influenced by the Arctic Ocean, as well as flat relief facilitating the unhindered exchange air masses between north and south. Winter in the polar latitudes is severe and lasts up to 8 months (the polar night lasts almost 3 months); the average January temperature is from -23 to -30 °C. In the central part of the plain, winter lasts almost 7 months; the average January temperature is from -20 to -22 °C. In the southern part of the plain, where the influence of the Asian anticyclone is increasing, at the same average monthly temperatures, winter is shorter - 5–6 months. Minimum air temperature -56 °C. The duration of snow cover in the northern regions reaches 240–270 days, and in the southern regions - 160–170 days. The thickness of the snow cover in the tundra and steppe zones is 20–40 cm; in the forest zone, from 50–60 cm in the west to 70–100 cm in the east. In summer, the western transfer of Atlantic air masses predominates with intrusions of cold arctic air in the north, and dry warm air masses from Kazakhstan and Central Asia. In the north of the plain, summer, which occurs under polar day conditions, is short, cool, and humid; in the central part - moderately warm and humid, in the south - arid and dry with dry winds and dust storms. The average July temperature rises from 5 °C to Far North up to 21–22 °C in the south. The duration of the growing season in the south is 175–180 days. Atmospheric precipitation falls mainly in summer (from May to October - up to 80% of precipitation). Most precipitation - up to 600 mm per year - falls in the forest zone; the wettest are the Kondinskaya and Sredneobskaya lowlands. To the north and south, in the tundra and steppe zone, the annual precipitation gradually decreases to 250 mm.

surface water

On the territory of the West Siberian Plain, more than 2,000 rivers flow, belonging to the basin of the Arctic Ocean. Their total flow is about 1200 km 3 of water per year; up to 80% annual runoff occurs in spring and summer. The largest rivers - the Ob, Yenisei, Irtysh, Taz and their tributaries - flow in well developed deep (up to 50–80 m) valleys with a steep right bank and a system of low terraces on the left bank. The feeding of the rivers is mixed (snow and rain), the spring flood is extended, the low water is long summer-autumn and winter. All rivers are characterized by slight slopes and low flow rates. The ice cover on the rivers lasts up to 8 months in the north, up to 5 months in the south. Large rivers are navigable, are important rafting and transport routes, and, in addition, have large reserves hydropower resources.

There are about 1 million lakes on the West Siberian Plain, the total area of ​​which is more than 100 thousand km2. The largest lakes- Chany, Ubinskoye, Kulundinskoye, etc. Lakes of thermokarst and moraine-glacial origin are widespread in the north. There are many small lakes in the suffusion depressions (less than 1 km 2): on the interfluve of the Tobol and Irtysh - more than 1500, on the Baraba lowland - 2500, among them there are many fresh, salty and bitter-salty ones; there are self-sustaining lakes. The West Siberian Plain is distinguished by a record number of swamps per unit area (the area of ​​the wetland is about 800 thousand km 2).

Landscape types

The uniformity of the relief of the vast West Siberian Plain determines the clearly pronounced latitudinal zonality of landscapes, although, compared with the East European Plain, the natural zones here are shifted to the north; landscape differences within the zones are less noticeable than on the East European Plain, and the zone of broad-leaved forests is absent. Due to the poor drainage of the territory, hydromorphic complexes play a prominent role: swamps and swampy forests occupy about 128 million hectares here, and in the steppe and forest-steppe zones there are many solonetzes, solods and solonchaks.

On the Yamal, Tazovsky and Gydansky peninsulas, in conditions of continuous permafrost, landscapes of arctic and subarctic tundra with moss, lichen and shrub (dwarf birch, willow, alder) vegetation have formed on gleyzems, peat-gleyzems, peat-podburs and soddy soils. Polygonal grass-hypnum swamps are widespread. The share of primary landscapes is extremely insignificant. To the south, tundra landscapes and swamps (mostly flat-hummocky) are combined with larch and spruce-larch woodlands on podzolic-gley and peat-podzolic-gley soils, forming a narrow forest-tundra zone, transitional to the forest (forest-bog) zone temperate zone, represented by subzones of the northern, middle and southern taiga. Swampiness is common to all subzones: over 50% of the area of ​​the northern taiga, about 70% of the middle taiga, and about 50% of the southern taiga. The northern taiga is characterized by flat and large hillocky raised bogs, the middle taiga is characterized by ridge-hollow and ridge-lake bogs, the southern taiga is characterized by ridge-hollow, pine-shrub-sphagnum, transitional sedge-sphagnum and low-lying tree-sedge bogs. The largest swamp Vasyugan Plain. The forest complexes of different subzones, formed on the slopes with varying degrees drainage.

Northern taiga forests on permafrost are represented by sparse low-growing, heavily waterlogged, pine, pine-spruce and spruce-fir forests on gley-podzolic and podzolic-gley soils. The indigenous landscapes of the northern taiga occupy 11% of the plain area. Indigenous landscapes in the middle taiga occupy 6% of the area of ​​the West Siberian Plain, in the southern - 4%. Common to the forest landscapes of the middle and southern taiga is the wide distribution of lichen and shrub-sphagnum pine forests on sandy and sandy loamy illuvial-ferruginous and illuvial-humus podzols. On loams in the middle taiga, along with extensive swamps, spruce-cedar forests with larch and birch forests are developed on podzolic, podzolic-gley, peat-podzolic-gley and gley peat-podzols.

In the subzone of the southern taiga on loams - spruce-fir and fir-cedar (including urman - dense dark coniferous forests with a predominance of fir) small-grass forests and birch forests with aspen on sod-podzolic and sod-podzolic-gley (including with a second humus horizon) and peat-podzolic-gley soils.

The subtaiga zone is represented by park pine, birch and birch-aspen forests on gray, gray gley and soddy-podzolic soils (including those with a second humus horizon) in combination with steppe meadows on cryptogley chernozems, solonetsous in places. Indigenous forest and meadow landscapes are practically not preserved. Boggy forests turn into lowland sedge-hypnum (with ryams) and sedge-reed bogs (about 40% of the zone). Forest-steppe landscapes of sloping plains with loess-like and loess covers on salt-bearing tertiary clays are characterized by birch and aspen-birch groves on gray soils and solods in combination with forb-grass steppe meadows on leached and cryptogleyed chernozems, to the south - with meadow steppes on ordinary chernozems, in places solonetzic and saline. On the sands are pine forests. Up to 20% of the zone is occupied by eutrophic reed-sedge bogs. In the steppe zone, the primary landscapes have not been preserved; in the past, these were forb-feather grass steppe meadows on ordinary and southern chernozems, sometimes saline, and in drier southern regions - fescue-feather grass steppes on chestnut and cryptogley soils, gley solonetzes and solonchaks.

Environmental issues and protected natural areas

In areas of oil production due to pipeline breaks, water and soil are polluted with oil and oil products. In forestry areas - overcutting, waterlogging, the spread of silkworms, fires. In agrolandscapes, there is an acute problem of lack of fresh water, secondary salinization of soils, destruction of soil structure and loss of soil fertility during plowing, drought and dust storms. In the north, there is degradation of reindeer pastures, in particular due to overgrazing, which leads to a sharp reduction in their biodiversity. Equally important is the problem of conservation hunting grounds and habitats for fauna.

To study and protect typical and rare natural landscapes, numerous reserves, national and natural parks. Among the largest reserves: in the tundra - the Gydansky reserve, in the northern taiga - the Verkhnetazovsky reserve, in the middle taiga - the Yugansky reserve and Malaya Sosva, etc. national park Pripyshminsky Bory. Natural parks are also organized: in the tundra - Deer streams, in the north. taiga - Numto, Siberian Ridges, in the middle taiga - Kondinsky lakes, in the forest-steppe - Bird's harbor.

The first acquaintance of Russians with Western Siberia took place, probably, as early as the 11th century, when the Novgorodians visited the lower reaches of the Ob River. With the campaign of Yermak (1582–85), a period of discoveries began in Siberia and the development of its territory.

Eastern territories Russian Asia open from Ural mountains view of the West Siberian Plain. Its settlement by Russians began in the 16th century, from the time of Yermak's campaign. The path of the expedition ran from the south of the plain.

These areas are still the most densely populated. However, it must be remembered that already in the 11th century the Novgorodians established trade relations with a population on the lower reaches of the Ob.

Geographical position

The West Siberian Plain is washed by the harsh Kara Sea from the north. In the east, along the border of the Yenisei River basin, it is adjacent to the Central Siberian Plateau. The southeast is guarded by the snowy foothills of Altai. In the south, the Kazakh uplands became the boundary of the flat territories. Western border, as mentioned above, are the oldest mountains of Eurasia - the Urals.

Relief and landscape of the plain: features

The unique feature of the plain is that all the heights on it are very weakly expressed, both in absolute and in relative terms. The terrain of the West Siberian Plain is very low-lying, with many river channels, swampy over 70 percent of the territory.

The lowland stretches from the shores of the Arctic Ocean to the southern steppes of Kazakhstan, and almost all of it is located within the territory of our country. Plain provides unique opportunity see five at once natural areas with their characteristic landscape and climate conditions.

The relief is typical for low-lying river basins. Small hills alternating with swamps occupy the interfluve areas. The area with saline groundwater dominates in the south.

Natural areas, cities and plain regions

Western Siberia is represented by five natural zones.

(Swampy area in the tundra of the Vasyugan swamps, Tomsk region)

The tundra occupies a narrow strip of the north of the Tyumen region and almost immediately passes into the forest tundra. In the extreme northern areas, one can find arrays of a combination of lichens, mosses of Western Siberia. The swampy terrain prevails, turning into light forest forest-tundra. The vegetation here is larch and thickets of shrubs.

The taiga of Western Siberia is characterized by dark coniferous zones with a variety of cedar, northern spruce and fir. Occasionally, pine forests can be found, occupying areas between swamps. Most of the lowland landscape is occupied by endless swamps. One way or another, the whole of Western Siberia is characterized by swampiness, but there is also a unique natural massif here - the largest swamp in the world, Vasyuganskoye. It took large territories in the southern taiga.

(forest-steppe)

Closer to the south, nature changes - the taiga brightens, turning into a forest-steppe. Aspen-birch forests and meadows with copses appear. The Ob basin is adorned with natural island pine forests.

The steppe zone occupies the south of the Omsk and the southwestern part of the Novosibirsk regions. Also, the area of ​​​​distribution of the steppe reaches the western part Altai Territory, which includes the Kulunda, Aleiskaya and Biyskaya steppes. The territory of ancient water drains is occupied by pine forests

(Fields in the taiga of the Tyumen region, Yugra)

The West Siberian Plain provides an opportunity for active land use. It is very rich in oil and almost all lined with mining towers. The developed economy of the region attracts new residents. Large cities of the northern and central parts of the West Siberian Plain are well known: Urengoy, Nefteyugansk, Nizhnevartovsk. In the south of the city of Tomsk, Tyumen, Kurgan, Omsk.

Rivers and lakes of the plains

(The Yenisei River in hilly-flat terrain)

Rivers flowing through the territory of the West Siberian Lowland flow into the Kara Sea. The Ob is not only the longest river of the plain, but together with the tributary the Irtysh is the longest waterway Russia. However, there are rivers on the plain that do not belong to the Ob basin - Nadym, Pur, Taz and Tobol.

The area is rich in lakes. They are divided into two groups according to the nature of their occurrence: part was formed in pits dug by a glacier that passed through the lowland, part - in places of ancient swamps. The area holds the world record for wetlands.

Plain climate

Western Siberia in its north is covered permafrost. A continental climate is observed throughout the plain. Most of the territory of the plain is very susceptible to the influence of its formidable neighbor - the Arctic Ocean, whose air masses freely dominate the lowland region. Its cyclones dictate the regime of precipitation and temperatures. In the plains where the arctic, subarctic and temperate zone often there are cyclones, leading to rain. In winter, cyclones generated at the junctions of moderate and arctic zones, soften frosts in the north of the plains.

More precipitation falls in the north of the plain - up to 600 ml per year. The temperature in the north in January, on average, does not rise above 22 ° C of frost, in the south at the same time frost reaches 16 ° C. In July, in the north and south of the plain, respectively, 4 ° C and 22 ° C.

The West Siberian Plain belongs to the accumulative type and is one of the largest low-lying plains on the planet. Geographically, it belongs to the West Siberian plate. On its territory are regions Russian Federation and northern part of Kazakhstan. Tectonic structure The West Siberian Plain is ambiguous and diverse.

Russia is located on the territory of Eurasia, the big continent on a planet that includes two parts of the world - Europe and Asia. The tectonic structure of the Ural Mountains separates the cardinal points. The map makes it possible to visually see the geological structure of the country. Tectonic zoning divides the territory of Russia into such geological elements like platforms and folded areas. Geological structure is directly related to the topography of the surface. Tectonic structures and landforms depend on which area they belong to.

Within Russia there are several geological areas. The tectonic structures of Russia are represented by platforms, folded belts and mountain systems. On the territory of the country, almost all areas have undergone folding processes.

The main platforms within the territory of the country are East European, Siberian, West Siberian, Pechora and Scythian. They, in turn, are divided into plateaus, lowlands and plains.

Relief of Western Siberia

The territory of Western Siberia gradually plunges from south to north. The relief of the territory is represented by a wide variety of its forms and is complex in origin. One of important criteria relief is the difference in absolute elevations. On the West Siberian Plain, the difference in absolute marks is tens of meters.

The flat terrain and slight elevation changes are due to the small amplitude of plate movement. On the periphery of the plain, the maximum amplitude of uplifts reaches 100-150 meters. In the central and northern parts, the amplitude of subsidence is 100-150 meters. The tectonic structure of the Central Siberian Plateau and the West Siberian Plain was relatively calm in the Late Cenozoic.

The geographical structure of the West Siberian Plain

AT geographically in the north, the plain borders on the Kara Sea, in the south, the border runs along the north of Kazakhstan and captures a small part of it, in the west it is controlled by the Ural Mountains, in the east - by the Central Siberian Plateau. From north to south, the length of the plain is about 2500 km, the length from west to east varies from 800 to 1900 km. The area of ​​the plain is about 3 million km2.

The relief of the plain is monotonous, almost even, occasionally the height of the relief reaches 100 meters above sea level. In its western, southern and northern parts, the height can reach up to 300 meters. The lowering of the territory occurs from south to north. In general, the tectonic structure of the West Siberian Plain is reflected in the terrain.

The main rivers flow through the territory of the plain - the Yenisei, the Ob, the Irtysh, there are lakes and swamps. The climate is continental.

Geological structure of the West Siberian Plain

The location of the West Siberian Plain is confined to the epihercynian plate of the same name. The basement rocks are highly dislocated and belong to the Paleozoic period of time. They are covered with a layer of marine and continental Mesozoic-Cenozoic deposits (sandstones, clays, etc.) more than 1000 meters thick. In the depressions of the foundation, this thickness reaches up to 3000-4000 meters. In the southern part of the plain, the youngest are observed - alluvial-lacustrine deposits, in the northern part there are more mature - glacial-marine deposits.

The tectonic structure of the West Siberian Plain includes a basement and a cover.

The foundation of the slab has the form of a depression with steep sides from the east and northeast and gentle sides from the south and west. The basement blocks belong to the pre-Paleozoic, Baikal, Caledonian and Hercynian times. The foundation is dissected by deep faults different ages. The largest faults of submeridional strike are East Zauralsky and Omsk-Pursky. The map of tectonic structures shows that the basement surface of the plate has an outer marginal belt and Inner area. The entire surface of the foundation is complicated by a system of uplifts and depressions.

The cover is interbedded with coastal-continental and marine deposits with a thickness of 3000-4000 meters in the south and 7000-8000 meters in the north.

Central Siberian Plateau

The Central Siberian Plateau is located in the north of Eurasia. It is located between the West Siberian plain in the west, the Central Yakut plain in the east, the North Siberian lowland in the north, the Baikal region, Transbaikalia and the Eastern Sayan mountains in the south.

The tectonic structure of the Central Siberian Plateau is confined to Siberian platform. The composition of its sedimentary rocks corresponds to the period of the Paleozoic and Mesozoic. Characteristic rocks for it are bedded intrusions, which consist of traps and basalt covers.

The relief of the plateau consists of wide plateaus and ridges, at the same time there are valleys with steep slopes. Average Height the difference in the relief is 500-700 meters, but there are parts of the plateau, where the absolute mark rises above 1000 meters, such areas include the Angara-Lena plateau. One of the highest parts of the territory is the Putorana Plateau, its height is 1701 meters above sea level.

median ridge

chief watershed range Kamchatka is a mountain range consisting of systems of peaks and passes. The ridge stretches from north to south and its length is 1200 km. A large number of passes are concentrated in its northern part, the central part represents large distances between the peaks, in the south there is a strong dissection of the massif, and the asymmetry of the slopes characterize the Sredinny Range. The tectonic structure is reflected in the relief. It consists of volcanoes, lava plateaus, mountain ranges, peaks covered with glaciers.

The ridge is complicated by structures of the lower order, the most striking of them are the Malkinsky, Kozyrevsky, Bystrinsky ridges.

The highest point belongs to and is 3621 meters. Some volcanoes, such as Khuvkhoytun, Alnay, Shishel, Ostraya Sopka, exceed the mark of 2500 meters.

Ural mountains

The Ural Mountains are a mountain system that is located between the East European and West Siberian plains. Its length is more than 2000 km, the width varies from 40 to 150 km.

The tectonic structure of the Ural Mountains belongs to the ancient folded system. In the Paleozoic, there was a geosyncline and the sea splashed. Beginning with the Paleozoic, there is a formation mountain system Ural. The main formation of folds occurred in the Hercynian period.

Intensive folding took place on the eastern slope of the Urals, which was accompanied by deep faults and the release of intrusions, the dimensions of which reached about 120 km in length and 60 km in width. The folds here are compressed, overturned, complicated by overthrusts.

Folding was less intense on the western slope. The folds here are simple, without overthrusts. There are no intrusions.

Pressure from the east was created by a tectonic structure - the Russian platform, the foundation of which prevented the formation of folding. Gradually, folded mountains appeared on the site of the Ural geosyncline.

AT tectonic plan the entire Urals is a complex complex of anticlinoria and synclinoria, separated by deep faults.

The relief of the Urals is asymmetrical from east to west. East slope drops steeply towards the West Siberian Plain. The gentle western slope smoothly passes into the East European Plain. The asymmetry was caused by the activity of the tectonic structure of the West Siberian Plain.

Baltic Shield

It belongs to the northwest of the East European Platform, is the largest protrusion of its basement and is elevated above sea level. In the northwest, the border runs with the folded structures of Caledonia-Scandinavia. In the south and southeast, the rocks of the shield submerge under the cover of sedimentary rocks of the East European Plate.

Geographically, the shield is tied to the southeastern part Scandinavian Peninsula, to the Kola Peninsula and Karelia.

The structure of the shield involves three segments, different in age - South Scandinavian (western), Central and Kola-Karelian (eastern). The South Scandinavian sector is tied to the south of Sweden and Norway. The Murmansk block stands out in its composition.

The central sector is located in Finland and Sweden. It includes the Central Kola block and is located in the central part of the Kola Peninsula.

The Kola-Karelian sector is located on the territory of Russia. It belongs to the most ancient formation structures. In the structure of the Kola-Karelian sector, several tectonic elements are distinguished: Murmansk, Central Kola, Belomorian, Karelian, they are separated from each other by deep faults.

Kola Peninsula

Tectonically tied to the northeastern part of the Baltic crystal shield, composed of rocks ancient origin- granites and gneisses.

The relief of the peninsula adopted the features of the crystalline shield and reflects traces of faults and cracks. On the appearance The peninsulas were influenced by glaciers that flattened the tops of the mountains.

The peninsula is divided into western and eastern parts according to the nature of the relief. The relief of the eastern part is not as complex as the western one. The mountains of the Kola Peninsula are in the form of pillars - on the tops of the mountains there are flat plateaus with steep slopes, at the bottom there are lowlands. The plateau is cut by deep valleys and gorges. The Lovozero tundra and the Khibiny are located in the western part, the tectonic structure of the latter belongs to mountain ranges.

Khibiny

Geographically, the Khibiny are assigned to the central part of the Kola Peninsula, they are a large mountain range. The geological age of the massif exceeds 350 Ma. Mountain Khibiny is a tectonic structure, which is an intrusive body (solidified magma) of complex structure and composition. From a geological point of view, an intrusion is not an erupted volcano. The massif continues to rise even now, the change is 1-2 cm per year. More than 500 types of minerals are found in the intrusive massif.

Not a single glacier has been found in the Khibiny, but traces of ancient ice are found. The tops of the massif are plateau-like, the slopes are steep with large quantity snowfields, avalanches are active, there are many mountain lakes. The Khibiny are relatively low mountains. The highest elevation above sea level belongs to Mount Yudychvumchorr and corresponds to 1200.6 m.

West Siberian Plain

The West Siberian Lowland is one of the largest low-lying accumulative plains in the world. It is located north of the low-hill plain of Kazakhstan and the Altai mountains, between the Urals in the west and the Central Siberian plateau in the east. Extending from north to south up to 2500 km, from W. to E. from 1000 to 1900 km; an area of ​​about 2.6 million sq. km 2. The surface is flat, slightly dissected, with small height amplitudes. The heights of the lowlands of the northern and central regions do not exceed 50-150 m, low elevations (up to 220-300 m) are characteristic mainly of the western, southern, and eastern margins of the plain. A strip of hills also forms the so-called. Siberian Ridges, stretching in the middle part of the Z.-S. R. from the Ob almost to the Yenisei. Wide, flat spaces of interfluves predominate everywhere, with slight slopes of the surface, heavily waterlogged and in places complicated by moraine hills and ridges (in the north) or by low sandy ridges (mainly in the south). Significant areas are occupied by flat ancient lake basins - woodlands. river valleys form a relatively sparse network and in the upper reaches most often represent shallow hollows with poorly pronounced slopes. Only a few of the largest rivers flow in well-developed, deep (up to 50-80 m) valleys, with a steep right bank and a system of terraces on the left bank.

Z.-S. R. formed within the epihercynian West Siberian plate, the basement of which is composed of intensely dislocated Paleozoic deposits. They are everywhere covered with a cover of loose marine and continental Meso-Cenozoic rocks (clays, sandstones, marls, etc.) with a total thickness of over 1000 m(in foundation depressions up to 3000-4000 m). The youngest Anthropogenic deposits in the south are alluvial and lacustrine, often covered by loess and loess-like loams; in the north - glacial, marine, and glacial-marine (capacity in places up to 200 m). In the cover of loose deposits Z.-S. R. closed horizons groundwater- fresh and mineralized (including brines), there are also hot (up to 100-150 ° C) waters (see West Siberian artesian basin). In the depths of Z.-S. R. the richest industrial deposits oil and natural gas(see West Siberian oil and gas basin).

The climate is continental, quite severe. In winter, masses of cold continental air of temperate latitudes predominate over the plain, and in the warm season an area of ​​low pressure is formed, and humid air masses come here more often from North Atlantic. The average annual temperatures are from -10.5°C in the north to 1-2°C in the south, the average temperatures in January are from -28 to -16°C, and in July from 4 to 22°C. The vegetation period in the extreme south reaches 175-180 days. The bulk of precipitation is brought by air masses from the west, mainly in July and August. Annual precipitation from 200-250 mm in tundra and steppe zones up to 500-600 mm in the forest zone. Snow cover thickness from 20-30 cm in the steppe up to 70-100 cm in the taiga of the Yenisei regions.

The territory of the plain drains more than 2,000 rivers, the total length of which exceeds 250,000 km. km. The largest of them are the Ob, Yenisei, Irtysh. The main sources of river nutrition are melted snow water and summer-autumn rains; up to 70-80% of the annual runoff occurs in spring and summer. There are many lakes, the largest are Chany, Ubinskoye, and others. Part of the lakes southern regions filled with salty and bitter-salty water. Large rivers are important navigable and rafting routes connecting the southern regions with the northern ones; The Yenisei, the Ob, the Irtysh, and the Tom have, in addition, large reserves of hydropower resources.

The flatness of the relief Z. - S. r. causes a distinctly pronounced latitudinal geographic zoning. specific feature In most zones of Western Siberia, there is excessive soil moisture and, as a result, the widespread swamp landscapes, which are replaced in the south by solonetzes and solonchaks. The north of the plain is a tundra zone, in which arctic, moss, and lichen landscapes form on arctic tundra and tundra gley soils, and in the south, shrub tundra. To the south there is a narrow strip of forest-tundra, where on peaty-gley, gley-podzolic and marsh soils complex landscape complexes of shrub tundra, spruce-larch woodlands, sphagnum and lowland bogs are developed. Most of the Z.-S. R. refers to the forest (forest-marsh) zone, within which coniferous taiga prevails on podzolic soils, consisting of spruce, fir, cedar, pine, Siberian larch; only in the extreme south of the zone are taiga massifs replaced by a strip of small-leaved birch and aspen forests. total area forests exceed 60 million hectares. ha, wood reserves 9 billion. m 3, and its annual growth is 100 million. m 3. The forest zone is distinguished by the wide development of raised ridge-hollow sphagnum bogs, which in some places account for more than 50% of the area. Of the animals of the forest zone, the following are typical: brown bear, lynx, wolverine, marten, otter, Siberian weasel, sable, elk, Siberian roe deer, squirrel, chipmunk, muskrat, and other representatives of the fauna of the European-Siberian subregion of the Palearctic.

To the south of the subzone of small-leaved forests, there is a forest-steppe zone, where leached and ordinary chernozems, meadow-chernozem, dark gray forest and marsh soils, solonetzes, solods . extreme southern part Z. - S. r. It occupies the steppe zone, in the north of which until recently forb feather grass steppes predominated, and in the south - feather grass-fescue steppes. Now these steppes, with their fertile chernozem and dark chestnut soils, have been plowed up, and only areas with saline soils in places have retained their virgin character.

Lit.: West Siberian lowland. Essay on nature, M., 1963; Western Siberia, M., 1963.

N. I. Mikhashov.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

See what the "West Siberian Plain" is in other dictionaries:

West Siberian Plain ... Wikipedia

Between the Urals in the west and the Central Siberian Plateau in the east. OK. 3 million km². The length from north to south is up to 2500 km, from west to east up to 1900 km. Height from 50 150 m in the northern and central parts to 300 m in the western, southern and ... ... Big Encyclopedic Dictionary

WESTERN SIBERIAN PLAIN, between the Urals in the west and the Central Siberian Plateau in the east. OK. 3 million km2. The length from north to south is up to 2500 km, from west to east up to 1900 km. Altitude from 50 to 150 m in northern and central parts up to 300 m in ... ... Russian history

One of the largest on earth. Takes b. h. Zap. Siberia, stretching from the coast of the Kara Sea in the north to the Kazakh uplands in the south, from the Urals in the west to the Central Siberian Plateau in the east. OK. 3 million km². Wide flat or ... Geographic Encyclopedia

Between the Urals in the west and the Central Siberian Plateau in the east About 3 million km2. The length from north to south is up to 2500 km, from west to east up to 1900 km. Height from 50 150 m in the northern and central parts to 300 m in the western, southern and eastern. ... ... encyclopedic Dictionary

West Siberian Plain- West Siberian Plain, West Siberian Lowland. One of the largest low-lying accumulative plains of the globe. It occupies most of Western Siberia, stretching from the coast of the Kara Sea in the north to the Kazakh uplands and ... Dictionary "Geography of Russia"

West Siberian Lowland the third largest plain on our planet after the Amazonian and Russian. Its area is about 2.6 million square kilometers. The length of the West Siberian Lowland from north to south (from the coast to the mountains of Southern Siberia and) is about 2.5 thousand kilometers, and from west to east (from to) - 1.9 thousand kilometers. The West Siberian Lowland is quite clearly demarcated from the north coastline seas, from the south - the hills of Kazakhstan and mountains, from the west - the eastern foothills of the Urals, and in the east - the valley of the Yenisei River.

The surface of the West Siberian Lowland is flat with a rather insignificant elevation difference. Small hills are characteristic mainly of the western, southern and eastern outskirts. There, their height can reach about 250-300 meters. The northern and central regions are characterized by lowlands with a height of 50-150 meters above sea level.

On the entire surface of the plain there are flat areas of interfluves, as a result of which they are significantly waterlogged. In the northern part, small hills and sandy manes are sometimes found. Quite impressive areas on the territory of the West Siberian Lowland are occupied ancient hollows, the so-called woodlands. here they are mainly expressed by rather shallow hollows. Only some of the largest rivers flow in deep (up to 80 meters) valleys.

Yenisei river

The glacier also had an impact on the nature of the relief of Western Siberia. The northern part of the plain was mainly affected by it. At the same time, water accumulated in the center of the lowland, as a result of which enough water was formed. flat plain. In the southern part, there are slightly elevated sloping plains with many shallow basins.

More than 2,000 rivers flow on the territory of the West Siberian Lowland. Their total length is about 250 thousand kilometers. The largest are . They are not only navigable, but also used to generate energy. They feed mainly on melt water and rain (in the summer-autumn period). There are also a large number of lakes here. In the southern regions they are filled with salt water. The West Siberian Lowland holds the world record for the number of swamps per unit area (the area of ​​the wetland is about 800 thousand square kilometers). The reasons for this phenomenon are the following factors: excessive moisture, flat terrain, and the ability of peat, which is available here in large quantities, to hold a significant amount of water.

Due to the large length of the West Siberian Lowland from north to south and the uniformity of the relief, there are many natural zones in its aisles. Sufficient in all areas large areas occupied by lakes and swamps. are absent here, and the zone is rather insignificant.

A large area is occupied by the zone, which is explained by the northern position of the West Siberian Plain. To the south is the forest-tundra zone. As mentioned above, the forests in this area are mostly coniferous. The forest-bog zone occupies about 60% of the territory of the West Siberian Lowland. The strip of coniferous forests is followed by a narrow zone of small-leaved (mainly birch) forests. The forest-steppe zone is formed in the conditions of a flat relief. Groundwater occurring here at a shallow depth is the cause a large number swamps. In the extreme southern part of the West Siberian Lowland is located, which is mostly plowed up.

In the flat southern regions of Western Siberia, a variety of manes are introduced - sandy ridges 3-10 meters in height (sometimes up to 30 meters), covered with pine forest, and kolki - birch and aspen groves that are scattered among the steppes.