Physical geography - Western Siberia (West Siberian Plain). Western

The article talks about climatic features characteristic of the territory of the West Siberian Plain. Contains information about temperature diversity inherent to annual seasonality. Reveals the reasons and factors that determine the climatic specificity of this piece of land.

Climate of the West Siberian Plain

This is an area with a fairly harsh continental climate. The length of the plain in the direction from north to south explains the zonality of the climate and the significant difference between the climatic conditions of the northern and southern lowland regions. Variability in quantity also plays an important role. solar radiation. This also includes the specifics of air mass circulation. Natural conditions even at the same latitude it is not significant, but they differ. The climate of the plain is determined by the presence of a natural barrier - the Urals, which “protects” the territory from warm westerly winds.

Rice. 1. Ural Mountains.

The region lies in an area that is considered a kind of transition area between the following climatic zones:

• moderate continental;
• sharply continental.

Winter is accompanied by low temperatures; there are almost no thaws here. Minimum temperatures in flat areas they are almost similar.

Even near the southern border there are quite severe frosts ranging from minus 50-52°. Almost like in the far north, but the distance between these points is over 2000 km.

Temperature of the West Siberian Plain

The spring season here is short and quite dry and cool.

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In April, even in the forested swamp region, the territory is far from the usual spring.

Summer temperatures in southern region explained by the presence of heated continental air from the south.

Due to the extensive swampiness of the territories, blood-sucking midges plague people and animals. It was found that in places where midges accumulate, more than 1,000 mosquitoes and 2,000 midges attack a person in 3 minutes.

Rice. 2. Siberian midge.

There is a lot of rainfall in July and August. This is due to activity on the Arctic and polar fronts.

Between May and October, the plain receives up to 70-80% of the annual precipitation.

Autumn comes here quite late.

The difference between the temperatures prevailing in summer and winter in the regions that belong to the Urals is not pronounced enough.

The left bank of the Yenisei is an area where a sharply continental climate prevails. There are no significant changes in altitude here, but there are small hills, lowlands and swamps.

Rice. 3. Yenisei.

It is not difficult to determine the climate type of the West Siberian Plain. It is predominantly continental.

For many of our compatriots, and even more so for most foreigners, the concept of Siberia is associated with a very harsh climate. Like many other cliches, this statement is only partially true. Of course, the weather conditions of the Siberian lands do not pamper their inhabitants, but they are not as extreme as is commonly believed. In addition, the climate tends to change, and Siberia is no longer as harsh as it was 100 years ago.

It is worth paying attention to the fact that Siberia occupies vast territories. There are still disputes about the geographical boundaries of the entire region (you can read more about this here - Geography and borders of Siberia), so when characterizing the climatic conditions of this region, we will limit ourselves only to the boundaries of the Siberian Federal District, conditionally dividing it into Western, Eastern and Northern parts .

Characteristics of the climate of Western Siberia

We included the following regions in the western part of Siberia - Omsk, Tomsk, Novosibirsk and Kemerovo Regions, Altai Territory and the Republics of Khakassia and Altai. Perhaps this part of Siberia has the mildest climate. The Altai Mountains protect the above regions from the Kazakh winds, and the extensive Vasyugan swamps soften the summer heat characteristic of the continental climate. Average temperature in winter it ranges from -15°C to -30°C. Due to strong winds, the frost in these places is felt a little stronger. Snow cover usually sets in at the end of November and reaches a thickness of 15-20 cm. Summer period characterized by a range from +15°C to +35°C, which is somewhat milder than in the Kazakh steppe. Thus, the climate of Western Siberia cannot be called ideal, but it cannot be called nightmarish either.

Climatic and weather conditions of Eastern Siberia

Eastern Siberia within the Siberian Federal District is Irkutsk Region, Republics of Tyva and Buryatia, Trans-Baikal Territory, as well as southern part Krasnoyarsk Territory. The climate of Eastern Siberia can be described as sharply continental. The average annual temperature is 0°C. In winter, temperatures can reach down to -40°C, but due to the lack of winds, the cold is relatively easily tolerated. IN winter time year, in the north of Eastern Siberia you can observe polar nights. Pitch darkness reigns, the sun may not appear for a month, or even more. The climate of Eastern Siberia is characterized by very sunny summers, during which it rarely rains. Maximum temperature in July-August it does not reach more than +15°C. Snow begins to fall in October, with a height of about 20-25 centimeters. During the year, precipitation falls in amounts from 300 to 500 mm per year, and in mountainous areas about 900-1000 mm.

Climate of the northern regions of Siberia.

Northern Territories Krasnoyarsk Territory, including the Dolgano-Nenets and Evenki regions - this is practically a real tundra. Here climatic conditions so severe that they could easily become a prototype of the prototype that has developed about Siberian climate. There is practically no summer in these parts, and the winter period is not only quite long, but also frosty. The duration of a temporary period with air temperature >10 °C in practice is less than one calendar month. In winter, the thermometer can easily drop below -40°C, and in summer it rarely rises above +10°C. In the mountains and northern regions snow cover lies all year round. Perhaps this is the real Siberia, the climate of which is a real test of a person’s will and endurance.

Weather conditions in different regions of Siberia.

In addition to a general description of the climatic conditions of Siberia, we have prepared descriptions of climate and weather for each of the 12 regions of the Siberian Federal District. More information about the weather in a particular city of the Siberian Federal District can be found here:

Characteristics of the climate of Siberia are complicated by its extreme diversity in different parts of the region, however, the data meteorological observations allow us to recognize the climate of Siberia as quite harsh.

At the same time, the long duration and low temperature of winter are compensated by a rapidly developing spring and a relatively hot summer; The average daily temperature in late March and early April rises in Verkhoyansk faster than anywhere else in the world, namely by more than half a degree per day, and July there corresponds to the average annual temperature of the 50th parallel. During the short summer in Yakutsk, many vegetables ripen, and barley sown in May is already reaped in mid-July. Rye and even wheat are sown in Yakutsk, and this is despite the presence of permafrost at a depth of only 1 meter. And the frosts themselves in Siberia, thanks to the usual calmness, are more easily tolerated than in other places. If we add to this that the average winter cloud cover in Siberia is about 50% and that it is especially small in the Lena basin, thanks to which (and the insignificant amount of water vapor in the atmosphere) even the low rising sun warms so much that sometimes even at -25° it drips from the rooftops, then the widespread opinion about severity must be considered exaggerated.

Cloudy December day. Calm.

As a feature of the Siberian climate that is unfavorable for humans and the economy, it should be noted that it is inconsistent both from day to day and from year to year. For example, the variability of the average daily temperature from day to day is equal to 3.6° in January and 1.7° in July for Irkutsk, 4.5° and 2.0° for Yakutsk, and 4.0° and 3.3 for Verkhoyansk °, whereas for most of the year in the European part of Russia it is less than 2 °. The number of days in a month when the change per day is more than 6° is for Western Europe 1.0 in winter and 0.3 in summer, while for Western Siberia the corresponding figures are 9.0 and 1.7. In some cases, these changes in Siberia reach significant values. So on February 14, 1894 in Yeniseisk from 7 a.m. to 9 p.m. the temperature rose from -40.3° to -17.0°, and on January 27, 1877 it dropped from -12.8° (at 1 p.m.) to - 42.4° by 7 am the next day. The temperature in Siberia undergoes significant changes from year to year. All these circumstances, in connection with the possibility of both very late spring and very early autumn frosts, make farming and especially gardening difficult in many places in Siberia, despite the sufficient amount of heat received during the summer.

General characteristics of the climate of Siberia

To understand the climate of Siberia as a whole, it is necessary to have general idea about the geophysical phenomena by which it is determined. If the surface of the globe were all water or all land, but of the same properties, then at all longitudes of each parallel circle there would be the same climate, depending only on latitude. The presence of both water and land, moreover, land that differs in both the nature of the surface and its height above sea level, causes differences in climate at different longitudes, determined mainly by the greater heat capacity of water, which heats up more slowly than land, as during during daylight hours and during the transition from winter to summer and cooling more slowly during the night and during the transition from summer to winter. As a result, from the beginning of autumn, the air density over land begins to become greater than over water, resulting in upper layers The atmosphere results in an influx of additional air masses towards the land, which, increasing the pressure above it, cause in the lower layers the movement of air from the center of the anticyclone formed in this way to its periphery. Air masses leaving in these directions are replaced by masses of cold air descending down in the central parts of the anticyclone, containing little water vapor, and thereby contribute to a decrease in cloudiness and even more rapid cooling of the surface of the central parts of the land. For the same reasons, during the summer, low pressure should be established over the land with an influx of moist and warm air from the surrounding seas to the central parts of the continent in the lower layers of the atmosphere (hence the increase in cloudiness and precipitation).

Late September in Western Siberia. The October pre-winter is ahead.

The larger the continent and the closer a certain area is to its center, the more clearly the continental climate is manifested, expressed in cold, dry and cloudless winters and relatively warm and more abundant precipitation in the summer. In coastal areas it manifests itself maritime climate with much milder winters and less warm summer and with relatively abundant autumn and winter precipitation. The anticyclone that sets up every winter in Siberia with its central part over Northern Mongolia cannot, however, be symmetrical either in the latitudinal or longitudinal direction. To the north of it is the Arctic Ocean, which is much colder than the Indian Ocean located to the south and separated by the Himalayas. To the east are the relatively warm Sea of ​​Okhotsk and the Pacific Ocean. From far away Atlantic Ocean the Asian anticyclone is separated by the Ural ridge. Due to these reasons, as well as the presence of the Stanovoy Ridge directed to the northeast, a relatively slow spreading of cold air occurs in a significant part of Northern Siberia to the east. At the end of the Stanovoy Ridge, this air, rushing east, turns south, as if flowing over the ridge and giving almost continuous strong dry and cold northern and northeastern winds to the northern coast of the Sea of ​​Okhotsk. This air circulation is facilitated by the deep “Aleutian” pressure minimum, which forms in the northern part of the Pacific Ocean in winter. On the contrary, in the north-west of Siberia, where the influence of relatively late freezing is felt Kara Sea and even the distant Gulf Stream, strong southern winds, also cold, but not so dry, dominate in winter (in particular, along the lower reaches of the Yenisei). The further to the west from the Yenisei valley, the weaker the northwestern spur of the high pressure area and the rarer and shorter the manifestations of the Yakut anticyclone, which at times approaches, bringing cloudless skies, almost complete calmness, and severe frosts. But, when one of the winter cyclones that originated in the north Atlantic Ocean along a wide trough low pressure, stretching from there along the northern shores of Eurasia, either through the Northern Urals or through the Kara Sea penetrates into Siberia, then clear frosty weather is replaced by less cold weather with a cloudy sky, snowfall and sharp winds from the western directions. Aerological observations in Siberia clearly indicate the existence of an inversion in winter in the region of the Siberian anticyclone (an increase in temperature as it rises above the earth's surface instead of the usual decrease). In the middle parts of Siberia, the lower layers of air, which are strongly cooled on long and clear nights, cannot mix with the upper layers and only flow down from the more high places into valleys, hollows and depressions, where almost all weather stations Yakutia, observations of which give such low temperatures in winter. The latter serve as an indication that the winter inversion is not a temporary, but a permanent phenomenon there. The Siberian anticyclone has been outlined since September, reaches its greatest development in February, and then, under the influence of a gradually increasing preponderance of heating of the soil and air by the sun's rays over night cooling, gradually dissolves, and in May begins to be replaced by a slightly low blood pressure(4-6 mm compared to the northern and eastern outskirts of Siberia, while the winter increase is about 15-20 mm). In the summer months, areas of high pressure are located in the southern steppe strip of the European part of Russia, above the Northern Arctic Ocean and in the subtropical Pacific. That's why summer weather in Siberia, although, in general, it has a typically continental character, it is still very often subject to changes caused by both high pressure areas invading from the southwest and cyclones penetrating into the territory of Western Siberia, mainly from the west (usually bypassing the Urals from the north or south), and in Eastern Siberia mainly from the east, and in Primorye (especially in its southern part) the influence of the Pacific monsoons is clear.

This general characteristic undergoes noticeable changes in many parts of Siberia due to local orographic features and can therefore have only a general guiding value for understanding the climate of Siberia, especially the climate of western Siberia, which is one huge plain.

Climate and agriculture of Siberia

The main feature of the climatic conditions of Siberia, which is of great importance in the agriculture of the region, is their extreme variability and diversity. On the one hand, we find here all types of farms - from reindeer herding farms in the northern tundra to beet and tobacco plantations in the south, on the other hand, at a comparatively insignificant distance, the same crop develops well in one place, but in another it is almost not applicable at all .

More noticeable for agriculture is the variability of climatic elements, in particular temperature and precipitation over time. The presence of an exceptional difference between winter and summer temperatures and the persistence of winter cold cause a rapid transition from winter to summer temperatures and significantly shorten the warm season. At the same time short spring and autumn are often significantly extended due to the summer by the return of severe cold in the spring and the early onset of frost in the fall, which is quite common for Siberia. Thanks to this, the absolutely frost-free period here is not very long; and in some years, even the warmest month, July, is not free from night frosts in many places.

Due to the low wind speed in the winter months, severe frosts in Siberia are more easily tolerated by animals.

The temperature period of +5°, which allows plant growth, is distinguished, in addition to its brevity, by very noticeable instability from year to year, which is especially felt in the northern regions of Siberia, where summer is shortest. In particular, in Yakutia, where the growing season on average ranges from 130 to 60; in 10 years there are only 2 good harvests, 3 average and 5 bad ones. The duration of the growing season in Siberia increases towards the south and west. Thus, in the Amur region, this duration ranges from 130 days (54° N) to 170 (48° N). The norm adopted for the growing season can be considered sufficient mainly for unpretentious plants, but for most crops the temperature limit should be increased to +10°. But even the onset of an average daily air temperature of 10° does not guarantee the absence of sudden cold spells that are destructive for agricultural plants. These circumstances not only exclude the possibility of growing crops that require a longer growing season, but even the crops cultivated here are always under threat of either immaturity or death from frost at the beginning or end of summer.

But if we take a formal approach to determining the possibility of growing agricultural crops here, using the climatic characteristics of their classification established in other places, we can come to the paradoxical conclusion that it is impossible to cultivate a whole range of crops here, even those crops that actually play a significant role in agriculture Siberia. This contradiction is explained by the fact that in most cases this classification is based on only two climatic characteristics - air temperature and precipitation - and does not take into account other characteristics, but among such characteristics there is a factor of enormous importance - solar energy directly perceived by the plant; It has been established that the abundance of light and the influx of solar energy significantly shortens the growing season. And in this regard, Siberia has a certain advantage over other countries located at the same latitudes, which partially compensates for the negative temperature conditions.

No less important economically for Siberia is the instability of precipitation over time. While in the European part of Russia the average long-term deviations of annual precipitation amounts are 12-18% and only in the south they rise to 25% (Astrakhan), in Siberia the average deviation reaches 36%, reaching even 160% in exceptional years. The precipitation amounts of individual months are even more variable from year to year. For them, the average deviation in Siberia ranges from 21 to 81%. But it should be noted that these deviations are generally greater for the time of year with less precipitation, i.e. in Siberia they are larger for the winter months and smaller for the summer months, which decide the fate of the harvest. However, relatively smaller fluctuations in precipitation amounts in the summer months are still absolute value quite large. During the year, with a total, relatively small annual amount, precipitation in Siberia is still distributed favorably. They fall mainly in the summer in the form of short-term showers, often accompanied by rainfall, with the heaviest precipitation in July and then August. The amount of summer precipitation ranges from 45 to 70% of the annual amount, and July precipitation from 15 to 35%. Also, a larger percentage of precipitation occurs in autumn than in spring. This circumstance, although it is associated with a negative impact on harvesting, should still be considered favorable for agriculture in Siberia. With severe freezing of the soil and rapid melting of the snow cover, the main supply of soil moisture in the spring comes from last year’s autumn precipitation. In the same way, soil moistened in autumn is warmed up more easily and quickly by the spring rays of the sun, which in turn helps to accelerate the start of the growing season. However, a comparison of the amount of precipitation and crop yields gives reason to believe that the precipitation of the end of June and, to a lesser extent, the beginning of July is of decisive importance in Siberia.

Almost everywhere in the 3rd decade of June and 1st July, on average, a slight decrease in precipitation is observed. This gives reason to assume a slightly higher probability of dryness in these decades, compared to the rest. In general, the frequency of occurrence in June is less than in the spring months and is almost equal compared to July and August and even September. It should be noted that, with a relatively lower probability of dry periods occurring in June, they are little inferior to the nearest months in terms of stability: the duration of these periods is generally not much different from the duration of periods in other months.

Summer is everywhere larger number periods of bad weather with a predominantly longer duration than spring, and predominantly more such periods than autumn, but the duration of autumn periods turns out to be longer in the western part of Siberia and shorter east of Baikal. Finally, bad weather occurs more often and lasts longer in the fall than in the spring. From this we have to conclude that the weather in Siberia is more favorable for spring field work than for autumn work, i.e. a good harvest is still in danger unfavorable conditions cleaning

Precipitation winter period, generally very small in Siberia, are insufficient to form a thick snow cover, which is so insignificant here that the Altai, Sayan, Baikal regions and almost the entire east belong to the region of “climates with snowless winters.” Due to the weakness of the snow cover, the so-called snow cover is widespread in the eastern part of Siberia, and in the western part the soil freezes to a considerable depth. However, permafrost is not the enemy of agriculture: spring crops, including wheat, grow well in these places, since soil water collects above the permafrost, and plants do not suffer from droughts. Strong freezing of poorly protected soil prevents the spread of winter crops. In general, in Siberia, snow, usually formed when low temperatures, extremely small and dry, and therefore very mobile and easily blown away and carried away by the wind from open fields. In taiga places that are more protected from the wind, the snow cover becomes more developed. Therefore, the issue of snow retention measures is of great importance in Siberia.

Speaking about the northern limit of the spread of agriculture in Siberia, one must agree with the thought of A.I. Voeikov that it “can go far to the north, and if it is not there, then it depends only on the small population of the region and the lack of good communication routes.” Indeed, there is a sufficient amount of precipitation, a very warm summer for the latitudes of Siberia and an abundance of sun rays are conditions favorable for the development of agriculture. If we turn to the map of “the actual and climatically possible northern and upper (mountain) boundaries of agricultural crops in the USSR” compiled by G. Selyaninov, then in it one can find complete confirmation of Voeikov’s opinion. The map shows “random”, in Selyaninov’s terminology, crops along the Ob up to Obdorsk, along the Yenisei - to the confluence of the Lower Tunguska, i.e. near the Arctic Circle, and then near Verkhoyansk and Srednekolymsk, i.e. already far beyond the Arctic Circle. But more than that: Selyaninov, also noting the “accidental” crops near Verkhnekolymsk, which lies south of the Arctic Circle, characterizes the area along the Kolyma near the Arctic Circle as an area of ​​“real agriculture,” although he refrains from drawing a possible agricultural boundary here. Noteworthy is the fact that at all places where water arteries intersect, the border of actual agriculture makes a sharp bend, extending for a considerable distance to the side along each river. This clearly confirms the idea that the boundaries of the area of ​​actual agriculture in Siberia are currently compressed not by the climatic conditions of the region, but by the vast spaces that have not yet been fully developed.

Regarding northern border distribution of wheat, a crop that is more demanding in terms of climatic conditions, then this border, despite all the complexity and whimsicality of its convolutions, still in general terms reflects the climatic features of the region. Starting at Tobolsk, it gradually descends between Lake Chany and Ob almost to the latitude of the city of Kamen, then rises again along the Yenisei, above the mouth of the Angara, and then heads southeast to Baikal, crossing the latter already at the latitude of Ulan-Ude. Here, on the one hand, the bending of the isotherms characteristic of this region is affected, descending, as a rule, to the south between the Irtysh and Ob and rising to the north along the Yenisei, on the other hand, the microconditions of Eastern Siberia, where there are almost no plains, and in the mountains farming is generally hampered and steep slopes and low summer temperatures due to the high altitude. However, to the south of 53° north latitude in the mountains of Transbaikalia, as well as in the Sayan Mountains, as well as in the foothills and mountain valleys, there are very favorable conditions for vegetation, despite the short summer: bright sun, sufficient rain, moderate humid air. There are especially many such places in Altai. The indicated coincidence of the characteristic bends of the line of distribution of wheat to the north and the isotherms gives reason to think that in this case we have here a significant approach to the truly extreme climatic boundaries. It does not contradict this that in Yakutia, in separate islands, wheat spread even to the latitudes of Yakutsk; significantly smaller temperature fluctuations in the area of ​​the middle reaches of the Lena and its tributaries Olekma and Aldan make the climatic conditions of the area more favorable for agriculture than elsewhere in the same latitudes in Western Siberia. However, the presence of islands along the extreme upper reaches of the Lena, as well as along the Angara and its tributaries, and, in particular, the excessive tortuosity of the line between the Yenisei and the Ob, indicate that all the spaces actually accessible to it are far from being covered by wheat.

1. Geographical location.

2. Geological structure and relief.

3. Climate.

4. Inland waters.

5. Soil-vegetation cover and fauna.

6. Natural areas.

Geographical location

The border of the West Siberian Plain is clearly expressed in relief. Its border in the West is the Ural Mountains, in the East the Yenisei Ridge and the Central Siberian Plateau. In the north, the plain is washed by the waters of the Kara Sea, the southern edge of the plain enters the territory of Kazakhstan, and the southeastern borders with Altai. The area of ​​the plain is about 3 million km2. the length from north to south is almost 2500 km, from west to east 1500-1900 km. The southern part of the plain is the most developed by man, its nature has been changed to some extent. The northern and central parts of the plain began to be developed in the last 30-50 years in connection with the development of oil and gas.

Geological structure and relief

The geological structure of the plain is determined by its position on the Paleozoic West Siberian plate. The foundation of the slab is a huge depression with steep sides. It consists of the Baikal, Caledonian and Hercynian blocks, broken by deep faults. In the north, the foundation lies to a depth of 8-12 km. (Yamalo-Taz syneclise), in the middle part the depth is 3-4 km. (Middle Ob anteclise), to the south the depth decreases. The plate cover is represented by Mesozoic and Cenozoic sediments of continental and marine origin.

The territory of the West Siberian Plate has repeatedly undergone transgressions. The glaciation of Western Siberia was repeated several times: Demyansk, Samarovsk, Tazovsk, Zyryansk and Sartan. Glaciers moved from 2 centers: from the Polar Urals and the Putorana plateau. Unlike the Russian Plain, where meltwater flowed to the south, in Western Siberia, which has a general slope to the north, these waters accumulated at the edge of the glacier, forming periglacial reservoirs. In areas free of ice, deep freezing of the soil occurred.

The modern relief of the plain is due to geological structure and the influence of exogenous processes. The main orographic elements correspond to the tectonic structures of the plate, although the accumulation of Meso-Cenozoic strata compensated for the unevenness of the basement. The absolute heights of the plain are 100-150 meters, with hills and lowlands alternating within the plain. The general slope of the plain is to the north. Almost the entire northern half of the plain is less than 100 meters high. The marginal parts of the plain are elevated to 200-300 meters. These are the North Sosvinskaya, Verkhnetazovskaya, Lower Yisei uplands, the Priobskoye plateau, the Ishimskaya and Kulundinskaya plains. The strip of Siberian Uvals is clearly expressed in the middle part of the plain, stretching from the Urals to the Yenisei near 63˚N latitude, their average height 100-150 meters. The lowest areas (50-100 m) are located in the northern parts of Western Siberia. These are the Lower Ob, Nadym, Pur, Taz, Kondinsk, and Middle Ob lowlands. Western Siberia is characterized by: marine accumulative plains (on the Yamal and Gydan peninsulas), glacial and aquaglacial plains with moraine hills, ridges, etc. (central part of Western Siberia), alluvial-lacustrine plains (valleys of large rivers), denudation plains (southern part of Western Siberia).

Climate

The climate of Western Siberia is continental, arctic and subarctic in the north and temperate in the rest of the territory. It is more severe than on the Russian Plain, but softer than in Eastern Siberia. Continentality increases to the southeast of the plain. Radiation balance from 15 to 40 kcal/cm2 per year. At the same time, compared to the Russian Plain, Western Siberia receives slightly more solar radiation due to the lower frequency of cyclones. The western transport remains, but the influence of the Atlantic is noticeably weakened here. The flatness of the territory promotes deep meridian air exchange. In winter, the climate is formed under the influence of the spur of the Asian High, which stretches across the south of the plain and troughs of low pressure over the northern peninsulas. This contributes to the transport of cold continental air from the Asian High to the plain. Winds predominate from the south. In general, January isotherms are submeridian in nature, from -18˚-20˚С in the west to almost -30˚С in the Yenisei valley. The absolute minimum in Western Siberia is -55˚С. Snowstorms are common in winter. IN cold period 20-30% of precipitation falls. Snow cover sets in in the north in September, in the south in November and lasts from 9 months in the north to 5 months in the south. The thickness of the snow cover in the forest zone is 50-60 cm, in the tundra and steppe 40-30 cm. In summer over Western Siberia, the pressure gradually decreases to the southeast. Winds prevail in a northerly direction. At the same time, the role of Western transfer is increasing. July isotherms take latitudinal directions. In the north of Yamal the average July temperature is +4˚С, near the Arctic Circle +14˚С, in the south of the plain +22˚С. Absolute maximum +45˚С (extreme south). The warm period accounts for 70-80% of precipitation, especially in July-August. Droughts are possible in the south. Largest quantity precipitation per year (550-600 mm) falls in the middle reaches of the Ob from the Urals to the Yenisei. To the north and south the amount of precipitation decreases to 350 mm. The climate of Western Siberia largely contributes to the maintenance of permafrost. The northern and central parts of Siberia (more than 80% of its area) have a moisture coefficient greater than 1 (excessive moisture). Such conditions lead to the development of swamping in the area. In the south the coefficient is less than 1 (insufficient moisture).

Inland waters

Western Siberia is characterized by a huge accumulation of inland waters. Several thousand rivers flow on the plain, most of which belong to the Ob basin and, accordingly, the Kara Sea. Few rivers (Taz, Pur, Nadym, etc.) flow directly into the Kara Sea. In the south of the plain there are areas of internal (closed) drainage. All rivers of Western Siberia are characterized by low slopes, with a predominance of lateral erosion. The rivers are fed mixed, with a predominance of snow, in addition there is rain and swamp-soil. Flood occurs from April in the south to June in the north. The maximum water rise reaches 12 meters on the Ob, and 18 meters on the Yenisei. A prolonged flood is typical, despite the “friendly” spring. The rise is fast, and the fall of the water is very slow. Freeze-up lasts up to 5 months in the south and up to 8 months in the north. Ice jams are typical. The largest rivers are the Ob and Yenisei. The length of the Ob from the source of the Irtysh is 5410 km, and the basin area is 3 million km2. If we count the Ob from the confluence of the Biya and Katun rivers, then its length is 3650 km. In terms of water content, the Ob is second only to the Yenisei and Lena. The Ob flows into the Ob Bay (estuary). Largest influx- The Irtysh, and its tributaries are the Ishim, Tobol, and Konda. The Ob also has tributaries - Chulym, Ket, Vasyugan, etc. The Yenisei is the most abundant river in Russia, its length is 4092 km, the basin area is 2.5 million km2. Only a small left-bank part of the basin lies on the territory of Western Siberia. There are about 1 million lakes on the plain. The lake content varies from 1% in the south to 3% in the north. In the Surgut lowland it reaches 20%. In the south the lakes are brackish. The most large lake- Chans. It is drainless and salty. The maximum depth is 10 m. Swamps occupy about 30% of the territory of Western Siberia. In some places in the forest zone the swampiness reaches 80% (forest-swamp zone). The development of swamps is facilitated by: flat terrain, poor drainage, excessive moisture, prolonged floods and permafrost. The swamps are rich in peat. According to hydrogeological conditions, the plain is a West Siberian artesian basin.

Land cover and fauna

The soils are located as follows from north to south: tundra-gley, podzolic, sod-podzolic, chernozem and chestnut. At the same time, large areas are occupied by semi-hydromorphic soils due to swampiness. Therefore, most soils, unlike their analogues on the Russian Plain, have signs of gleyization. In the south there are solonetzes and solods. The vegetation of Western Siberia is to some extent similar to the vegetation of the Russian Plain, but there are differences that are associated with the wide distribution of swamps, the severity of the climate and the characteristics of the flora. Along with spruce forests, as well as pine, fir, cedar and larch forests are widespread. The forest-tundra is dominated by larch, and not spruce, as on the Russian Plain. Small-leaved forests here are not only secondary, but also primary. Mixed forests here are represented by pine and birch. Large areas in Western Siberia are occupied by floodplain vegetation (more than 4% of the plain), as well as swamp vegetation. Animal world has many similarities with the Russian Plain. In western Siberia there are about 500 species of vertebrates, of which 80 species are mammals, 350 species of birds, 7 species of amphibians and about 60 species of fish. There is a certain zoning in the distribution of animals, but band bur along rivers forest animals penetrate far to the north and south, and on lakes steppe zone There are inhabitants of polar reservoirs.

Natural areas

Natural zones on the plain extend latitudinally. Zoning is clearly expressed. Zones and subzones change gradually from north to south: tundra, forest-tundra, forests (forest-swamps), forest-steppe, steppe. Unlike the Russian Plain, there is no zone of mixed and deciduous forests, semi-desert and desert zones. The tundra extends from the coast of the Kara Sea and almost to the Arctic Circle. The length from north to south is 500-600 km. Polar day and night last here for almost three months. Winter is from October to mid-May. Average temperatures range from -20˚C in the west to -30˚C in the east. Winds and snowstorms are typical. Snow cover lasts for about 9 months. Summer lasts not much more than one month. The average temperature in August is +5˚C, +10˚C (but sometimes the air can warm up to +25˚C). Precipitation per year is 200-300 mm, but most of it falls in the warm period. Permafrost is widespread everywhere, so the tundra is characterized by solifluction processes, thermokarst, polygons, peat mounds, etc. There are many swamps and lakes. The soils are tundra-gley. The flora is not rich, only about 300 species of higher plants. Vegetation is especially sparse on the sea coast, where lichens are developed. arctic tundra from cladonia, etc. To the south, mosses begin to predominate and flowering plants appear - cotton grass, partridge grass, arctic bluegrass, and a number of sedges, etc. In the south of the zone, the tundra becomes shrubby, where, along with mosses and lichens, dwarf birches, willows, and alders grow; in some places on the southern slopes and river valleys - buttercups, lights, crowberry, polar poppy, etc. Among the animals live reindeer, wolf, arctic fox, lemming, voles, ptarmigan, snowy owl, many wading and waterfowl (waders, ducks, geese, etc.) arrive in the summer.

The forest-tundra stretches in a relatively narrow strip (50-200 km), expanding from the Urals to the Yenisei. It lies along the Arctic Circle and descends further south than on the Russian Plain. The climate is subarctic and more continental than in the tundra. And although winter here is somewhat shorter, it is more severe. The average temperature in January is -25-30˚C, the absolute minimum is up to -60˚C. Summers are warmer and longer than in the tundra. The average July temperature is +12˚C+14˚C. Permafrost is widespread. Therefore, the frozen topography again predominates, and erosion processes are limited. The zone is crossed by many rivers. The soils are gley-podzolic and permafrost-taiga. The tundra vegetation here is supplemented by sparse larch forests (their height is 6-8 meters). Dwarf birch is widespread, there are many swamps, and there are floodplain meadows in the river valleys. The fauna is richer than in the tundra; along with representatives of the tundra fauna, there are also inhabitants of the taiga.

Forests (taiga) occupy largest area Western Siberia. The length of this zone from north to south is 1100-1200 km, almost from the Arctic Circle to 56°N. in the south. There is an almost equal proportion of forests on podzolic soils of the taiga and peat-bog soils of sphagnum bogs. Therefore, the taiga of Western Siberia is often called the forest-swamp zone. The climate is temperate continental. Continentality increases from west to east. The average January temperature ranges from -18˚C in the southwest to -28˚C in the northeast. In winter, anticyclonic weather prevails. Cyclones often pass through the north of the taiga zone. The thickness of the snow cover is 60-100 cm. Summer is relatively long, the growing season is from 3 months. in the north up to 5 months. in the south. The average July temperature ranges from +14˚C in the north to +19˚C in the south. More than half of all precipitation falls in summer. The moisture coefficient is everywhere greater than 1. Permafrost is widespread in the north of the zone. Lots of swamps and rivers. Swamps are of various types, but ridge-hollow peatlands predominate, there are ridge-lake peats and swamps. Swamps are confined to the lowest places with stagnant moisture. On the hills, ridges of interfluves, on terraces river valleys Coniferous forests of spruce, fir, and cedar grow. In some places there are pine, larch, birch, and aspen. To the south of the taiga, 50-200 km wide, stretches a strip of small-leaved forests of birch and, to a lesser extent, aspen, on soddy-podzolic soils. Fauna presented Siberian species, but there are also “Europeans” (marten, European mink, otter). The most typical are brown bear, wolverine, lynx, sable, chipmunk, squirrel, fox, wolf, water rat, elk, there are many birds whose life is associated with the coniferous forest (nutcracker, bee-eater, kuksha, wood grouse, woodpeckers, owls, etc.), but there are few songbirds (hence the name “dead taiga”).

The forest-steppe stretches in a narrow strip (150-300 km) from the Urals to the Salair Ridge and Altai. The climate is temperate continental, with harsh winters with little snow and hot, dry summers. The average temperature in January is -17˚C-20˚C, and in July +18˚C+20˚C, (maximum +41˚C). Snow cover is 30-40 cm, annual precipitation is 400-450 mm. The moisture coefficient is less than 1. Suffusion processes are characteristic; there are lakes, some of which are saline. The forest-steppe is a combination of aspen-birch coppices on gray forest soils and areas of meadow steppes on chernozems. The forest cover of the zone ranges from 25% in the north to 5% in the south. The steppes are mostly plowed. The fauna is represented by forest and steppe species. In the steppes and floodplain meadows, rodents predominate - gophers, hamsters, earth hare, voles, there is a brown hare. In the groves there are foxes, wolves, weasels, ermine, ferrets, white hare, roe deer, black grouse, partridges, and in the ponds there are a lot of fish.

The steppe zone occupies the extreme south of Western Siberia. Unlike the steppes of the Russian Plain, here more lakes, the climate is more continental (little rainfall, cold winters). The average temperature in January is -17˚C-19˚C, and in July +20˚C+22˚C. Annual precipitation is 350-400 mm, with 75% of precipitation falling in summer. The humidification coefficient ranges from 0.7 in the north to 0.5 in the south of the zone. In summer there are droughts and hot winds, which leads to dust storms. The rivers are transit, small rivers dry up in summer. There are many lakes, mostly of suffusion origin, almost all salty. The soils are chernozem, in the south dark chestnut. There are salt marshes. The plowed state of the steppes reaches 90%. In the remaining areas of the steppes, various feather grasses, fescue, thyme, sage grass, wormwood, iris, steppe onion, tulip, etc. grow. In saline areas, they grow - saltwort, licorice, sweet clover, wormwood, chiya, etc. In wetter places there are caragana shrubs , spirea, rose hips, honeysuckle, etc., along river valleys they come to the south pine forests. In the floodplains of rivers there are swampy meadows. Fauna presented various rodents(ground squirrel, hamster, marmots, voles, pikas, etc.), among predators are the steppe ferret, corsac fox, wolf, weasel, among birds - the steppe eagle, buzzard, kestrel, larks; on the lakes there are waterfowl. In Western Siberia, 4 nature reserves have been created: Malaya Sosva, Yugansky, Verkhne-Tazovsky, Gydansky.

Eastern Siberia is characterized by pronounced continental climate features. This is manifested in exceptionally large seasonal differences in air temperature, low light rainfall on the territory. In winter, it is formed under the influence of a vast area of ​​elevated - Asian. However, the position of the center of the anticyclone, the pressure in it and the area of ​​distribution change significantly during the cold period. This determines the variability, which is associated with day-to-day fluctuations in air temperature, which is especially typical for the southwest of Yakutia.
Although cyclonic activity is weakened in winter, it significantly affects the weather: it changes, precipitation occurs, and it forms.
Continental air predominates here, which cools in the surface layer, and in December - February in the lower layers it becomes colder than the Arctic air. The average in January over the vast expanse of Eastern Siberia varies from -26 in the southwest to -38, -42° in the Central Lowland. In valleys and basins it can drop to -60°.
However, against the background of very low average monthly temperatures, when warmer continental air is carried out from Central Asia, relative warming is observed in the Baikal region and Transbaikalia, accompanied by an increase in temperature to -15° and above. With the long-term removal of relatively warm air masses, the air temperature during the day in Eastern Siberia can be above 0°.

Summer in Eastern Siberia is warm: up to 30 - 40% of solar heat is consumed to heat the air, and in the south and east of the Central Yakut Lowland up to 50%. Therefore, despite the flow of cold air from the seas, from the north and from the sea, average temperatures in July vary across the territory from north to south from 14 to 18°. The most high temperatures in these areas they occur when continental air is carried out from China and (35 - 38°).
In summer, the frequency of occurrence over Eastern Siberia is greater than in winter. They mainly come from the west, southwest and northwest. In the second half of summer, southern cyclones occur, which are associated with significant precipitation.
Relief and features distribute precipitation throughout the area. The annual amount of precipitation varies between 130 - 1000 mm, and there is no well-defined, as in the European territory of Russia and Western Siberia, gradual decrease in precipitation to the south. The combination of heat and moisture promotes forest growth across most of Eastern Siberia. However, the complex terrain of this region disrupts the natural environment.
The most favorable conditions (sufficient heat and moisture) develop in areas where precipitation falls from 600 to 1000 mm. To the east, in the territory of Central Yakutia, with a decrease in precipitation to 200 - 250 mm, aridity increases. Only here, at latitudes around 60 degrees, negative differences between precipitation and evaporation are observed, which forms steppe zones. The climate of its coasts is maritime in nature, which is determined by the large size of the lake and its isolation from the surrounding territory by mountain ranges. In winter, a center of low pressure forms over Lake Baikal. And from the area of ​​​​high pressure over Eastern Siberia they blow towards Lake Baikal. The minimum precipitation is observed in February - March (10 - 20 mm). In Transbaikalia, due to a decrease in precipitation to 300 - 400 mm, aridity increases from north to south. In the southwest and especially in the southeast of Transbaikalia, where evaporation exceeds precipitation by 200 mm, they form. However, greater aridity is observed in river valleys, in intermountain basins and on the southern slopes. Unlike other regions of Russia, in Eastern Siberia on the northern slopes it extends into the southernmost regions of Transbaikalia, and steppes along river valleys are found north of 60° N. w.