The 7 left tributaries of the Volga are rivers. Volga river

Its length is 3530 km, and the basin area of ​​1.3 million km² can be the envy of many European countries. In ancient times it was known as Ra, in the Middle Ages it was called Itil.

It begins among swampy lakes. Along a winding valley, moving from west to east, it flows through the Central Russian Upland. Each new tributary of the Volga, merging with it, makes it more and more full-flowing. Having reached the foothills of the Urals, near the city of Kazan, the channel turns sharply to the south and, breaking through a chain of ridges, emerges at the place where it flows into a huge delta.

The river system includes about 151 thousand different watercourses, the total length of which exceeds 574 thousand kilometers. 300 others, smaller in length, flow into the river. Most of them flow into it from the source to the city of Kazan. It should be noted that there are significantly more left tributaries than right ones, and besides, they are also much richer. 85 km from Kazan, the Kama, the largest tributary of the Volga, flows into the river.

Who is more important: ancient Ra or Kama

Really big and full-flowing the most important water artery the European part of Russia becomes after the merger with the Kama. Near the city of Togliatti, the dam of the Volzhskaya Hydroelectric Power Station, blocking the riverbed, forms the huge Kuibyshev Reservoir. The largest left tributary of the Volga flows into this reservoir.

According to the main hydrological indicators, the Kama should be considered the main one, and the Volga its right tributary. The first observations of scientists, carried out back in 1875, showed that at the confluence it carries in its channel 3100 m 3 of water per second, and the Kama - 4300. It turns out that the Volga tributary is more full-flowing. This is explained by the fact that the main part of its basin is located in the taiga zone, where precipitation falls more than in other parts of the Volga basin.

There are several other signs by which the Kama should be considered the main river. One of them is that its source is located above the beginning of the Volga, and in geography this is a sign of dominance. And in terms of the total number of tributaries, the great Russian river is inferior to the Kama.

And most importantly, the Kama already existed at a time when the most famous Russian river did not yet exist. In the first half, before the greatest glaciation, the Kama, merging with the Vishera, carried its waters along an ancient channel to the Caspian Sea.

But in the history of Russia and in its culture, the significance of big river Europe is undeniably more significant. Therefore, the Kama is a tributary of the Volga, period.

River up ice age

The Oka can also be considered the ancestor of the Volga, since its valley was formed even before the onset of the Ice Age. It begins on the Central Russian Upland, the height of its source is 226 m. It flows into the main river near the city of Nizhny Novgorod. The area of ​​its basin is 245,000 km 2. The length of the Oka is 1,480 kilometers, and its flow is a typical flat river with an average slope of about 0.11 o/oo. The largest right tributary of the Volga, according to the characteristics of the river valley and bed, is divided into upper and lower parts. Such people flow into the Oka famous rivers, like Moscow, Moksha and Klyazma.

The Volga River is located in the European part of Russia, it is one of the largest rivers on the planet, and also the largest in Europe. The length of the river reaches 3530 kilometers. The basin has an area of ​​1,360,000 square kilometers. The Volga River begins on the Valdai Hills and flows into the Caspian Sea. The mouth is located 28 meters below sea level. In total, the fall is 256 meters. The Volga River receives approximately 200 tributaries. The tributaries on the left side are more numerous and rich in water than those on the right. The Volga river system basin contains 151 thousand watercourses (rivers, streams and temporary watercourses) with a total length of 574,000 kilometers. The Volga basin is located on approximately one third of the European territory of Russia and extends from the Valdai and Central Russian Uplands to a third of the Urals. At the latitudes of Saratov, the basin narrows significantly and from Kamyshin straight to the Caspian Sea the Volga flows without tributaries. The main feeding part of the Volga water collection area, from the upper reaches to the cities of Kazan and Gorky, is located in the forest area. The basin partially reaches the vegetable gardens of Kuibyshev and Saratov, in the forest-steppe territory, the lower part - in the steppe territory to Volgograd, in the south - in the semi-desert territory. The Volga is divided into 3 zones: the upper Volga is located from the upper reaches to the mouth of the Oka, the middle Volga - from the inflow of the Oka right to the mouth of the Kama, the lower Volga - from the inflow of the Kama right to the mouth. Look what it looks like.

The source of the Volga is a spring near the village of Volgo-Verkhovye in the Kalinin region. At the source, within the boundaries of the Valdai Upland, the Volga flows through small lakes: Verkhit, Vselug, Sterzh, Peno. A dam was built in the upper reaches in 1843 (Verkhnevolzhsky Beishlot) to regulate wastewater and maintain navigable depths during low water periods. Between the cities of Rybinsk and Kalinin on the Volga, the Volga Reservoir is organized, which has a dam and hydroelectric power stations Uglichskoye, Ivankova Reservoir and Rybinsk Reservoir. On the territory of Rybinsk it is Yaroslavl, and in the lower reaches of Kostroma the river flows through a narrow valley between high banks, passing the Uglich-Danilovskaya, Galichsko-Chukhloma uplands. After this, the Volga flows through the Balakhninskaya and Unzhenskaya lowlands. Near the city of Volga, which is blocked by the Gorkovskaya dam, the Gorkovskoye reservoir is created. The most important tributaries of the upper Volga are: Selizharovka, Mologa, Tvertsa, Sheksna and Unzha. Compare with.

Middle current

In the middle reaches, just below the inflow of the Oka, the Volga becomes more water-rich. It flows along the northern edge of the Volga Upland. The right side of the bank is high, the left is low. The Cheboksary Hydroelectric Power Station was built near the city of Cheboksary, and the Cheboksary Reservoir is located just above the dam. The largest tributaries of the Volga in its middle course are: Oka, Vetluga, Sura, Sviyaga. After the Kama joins the lower reaches, the Volga becomes a strong river. It flows in this place along the Volga Upland. Near Togliatti, a little higher Samara Luka, formed by the Volga, bypassing the Zhiguli mountain heights, the Volzhskaya Hydroelectric Power Station dam was built. Just above the dam lies the Kuibyshev Reservoir. On the Volga, in the territory of the city of Balakovo, the Saratov hydroelectric power station dam was built. In the lower part, the Volga includes small tributaries - Samara, Vetluga, Bolshoy Irgiz, Ruslan. 21 kilometers above the city of Volgograd, the left branch, Akhtuba, 537 kilometers long, is disconnected from the Volga, it flows parallel to the main channel. The wide space between the Volga and Akhtuba, which is crossed big amount tributaries, old rivers, is called the Volga-Akhtuba floodplain. The width of the floods within the floodplain once reached 20–30 kilometers. On the Volga between the base of Akhtuba and Volgograd, the Volgograd Hydroelectric Power Station was built. The Volga delta originates in the place where the Buzan branch separates from its bed and is one of the largest in Russia. In the delta you can count up to 500 tributaries, branches, and small rivers. The main branches can be considered: Bakhtemir, Staraya Volga, Kamyzyak, Bolda, Akhtuba, Buzan. Where is .

The Volga is mainly fed by snow (60 percent of runoff per year), groundwater(30 percent) and precipitation (10 percent). The natural regime can be characterized by spring flooding from April to June, low water content in summer and winter period low water, autumn rain floods in October. The annual fluctuations in the degree of the Volga before regulation reached 11 meters near the city of Kalinin, 15-17 meters just below the Kama mouth, and 3 meters near Astrakhan. When the reservoir was built, level fluctuations in the Volga flow decreased sharply. On average for the year, the water flow at the Upper Volga beishlot was 29 cubic meters per second, at the city of Kalinin - 182, Yaroslavl - 1110, Gorky - 2970, Kuibyshev - 7720, Volgograd - 8060 cubic meters per second. In the lower part of Volgograd, the river loses approximately 2 percent of its own flow to evaporation. The highest water flows can be observed during floods. Find out what attractions there are in here.

Historical and geographical sketch

The geographical position of the Volga, as well as its large tributaries, had already determined its importance as a trade route between the West and the East by the 8th century. Metals and textiles from Slavic lands - honey, furs, wax - were exported directly from Central Asia. In the 9th–10th centuries in trade important role centers played: Itil, Novgorod, Bolgar, Rostov, Murom, Suzdal. From the 11th century, trade began to weaken, and in the 13th century, the Mongol-Tatar invasion destroyed economic ties, leaving only the upper Volga basin, where the cities of Novgorod, Tver and the cities of Vladimir-Suzdal Rus' were actively involved. Starting from the 14th century, the importance of the trade route was restored again, the centers were actively developing: Kazan, Astrakhan, Nizhny Novgorod.

Ivan the Terrible conquered the Kazan and Astrakhan khanates in the mid-16th century, this led to the entire Volga river system uniting in the hands of Russia, and thus this could contribute to the flourishing of Volga trade in the 17th century. New big cities are appearing - Samara, Tsaritsyn, Saratov; the main role is played by: Yaroslavl, Nizhny Novgorod, Kostroma. In the 19th century, the Volga trade route developed significantly, especially after the Mariinsky river system of the Volga and Neva basins was connected. A large river fleet appeared, and a large army of barge haulers was formed on the Volga. Large transportations began to take place along the Volga: bread, fish, salt, and later cotton and oil. Largest economic importance received the Nizhny Novgorod Fair.

During Civil War major events took place on the Volga fighting, and it acquired important military-strategic significance. During the socialist system, due to the industrialization of the entire state, the importance of the Volga began to increase every year. Starting from the late 30s of the 20th century, the Volga began to be used as a source of hydropower. During the Great Patriotic War in the years 1941–1945, the largest Battle of Stalingrad(1942 - 1943). When the war ended, economic role The Volga River began to grow and strengthen to a large extent, especially when several large hydroelectric power plants and reservoirs. At the moment when the construction of the Volga-Kama cascade of hydroelectric power stations was completed, electricity production began to reach 40–45 billion per year.

The mirror area of ​​the reservoirs began to amount to approximately 38,000 square kilometers, the full volume was 288 cubic kilometers, and the useful volume was 90 cubic kilometers. The Volga region, which contains 4 million hectares of land that are suitable for irrigation, is provided with water reserves from the Kuibyshev and Volgograd reservoirs. Work was carried out to water 9 million hectares and irrigate 1 million hectares of land in the Volga-Ural interfluve territory. In 1971, the Volga-Ural water canal was built with a length of 425 kilometers. The river system contains more than 41,000 kilometers of rafting routes and approximately 14,000 kilometers of navigable routes.

The Volga is connected to the Baltic Sea through the Volga-Baltic Waterway named after Vladimir Ilyich Lenin, the Tikhvin and Vyshnevolotsk systems; through the Severodvinsk system, as well as through the White Sea - Baltic Canal with the White Sea; with Black and Seas of Azov‒ through the Volga-Don Canal named after Vladimir Ilyich Lenin.

In the upper Volga basin there are large forests; in the Middle and Lower Volga regions, vast territories are given over to crops and crops. industrial crops. Gardening and melon growing are developed. The Volga-Ural territory has rich oil and gas fields. Not far from Solikamsk you can see large deposits potassium salts. There are deposits in the Lower Volga region table salt. There are approximately 70 species of fish in the Volga, 40 of which are commercial (roach, bream, herring, pike perch, catfish, carp, pike, sturgeon, sterlet).

The most powerful and largest tributary of the Volga is the Kama, which ranks second, if we take the rivers of the European part of our country, in terms of its catchment area, amounting to 522,000 km 2, and, of course, in length, equal to as much as 2030 km. First place, as expected, goes to the Volga. The second largest tributary of the Volga, the Oka, begins in the center of the Central Russian Upland, at an altitude of 226 meters above sea level. It flows into the great Russian river from the right, right near the city of Gorky. The Kama begins within the boundaries of the Upper Kama Plateau.

Kama. Description of the inflow

First we'll look at major tributaries Volga. The Upper Kama Plateau is the northern side of the High Trans-Volga region. The river first flows north, then at an angle of 90 degrees it turns east and in the foothills of the Urals changes direction again, turning very sharply to the south. It turns out that in the upper reaches it forms a kind of large loop. Considering that the total length exceeds 2000 km, from the source to its mouth it is only 445 km. This reshaping of the Kama became possible due to its glaciation. It belongs to the lowland rivers, although its slope is twice that of the Volga.

The Kama is shallow in its upper reaches and only when the Vishera, which is characterized by high water content, flows into it does it become truly full-flowing. It flows in a deep valley with very solid banks from the mouth of the Vishera to the place where the next tributary, Chusovaya, flows into it. Water mode the Kama is more difficult than other rivers European Russia. This tributary of the Volga is influenced by the mountain tributaries of the left bank, which are very watery and have a different regime. This is especially noticeable after Vishera flows into it.

What does Kama eat?

Snow waters play a major role in the nutrition of the Kama. Their share in the annual runoff is more than 50%. Ground and rain feeding are also noticeable. The main features of the water regime are almost completely the same as those of the Volga. However, Kama has a more erratic summer low level water, it is often interrupted by floods due to rains, sometimes reaching significant levels. The water level fluctuates up to 10-12 meters. This is happening, for example, near the city of Molotov. The river freezes in mid-November and opens up by April, its second half. Kama accepts it herself a large number of tributaries, of which the most important and important are the Chusovaya, Vishera, Vyatka and Belaya.

Oka is the next largest tributary of the Volga

The Oka River, with a basin of 245,000 km 2, accounts for 51% of the total drainage area of ​​the entire Upper Volga. Oka has a length of 1480 km. It is a typical river of the lowland European part of Russia. The main tributaries are Moscow, Moksha and Klyazma. The river is divided into two different parts, according to the nature of the channel and valley: the upper, starting at the source, and the lower, after the confluence of Moscow, covering the rest, most of the river.

Where the upper course is located, it runs along the Central Russian Upland, has a predominantly deeply incised, narrow river valley and significant slopes, given that the river is flat. The right tributary of the Volga, the Oka, flows below the confluence of Moscow, in the area of ​​the large Oka lowland, where there are many lakes and swamps, and resembles the Belarusian Polesie in its character. Its valley widens noticeably, sometimes up to 25-30 km, in lake-like extensions. There are numerous manes on the wide floodplain of the river, the levels between them are filled with oxbow lakes.

Oka mode

The Oka pool is located among deciduous forests, where evaporation is greater than in the upper Volga basin, and only 7% of precipitation turns into runoff. The water regime of these places is characterized by standard features for rivers in the forest zone of this part of Europe. But even here, the Oka, the right tributary of the Volga, is distinguished by a special regime: frequent and high floods - in summer and autumn, sometimes they reach the size of a regular spring flood. The river is characterized by enormous fluctuations in water level in the middle and upper reaches. In 1908, there was a high, catastrophic flood, when the level of the city of Kaluga reached 18 meters. Such noticeable level fluctuations on the Upper Oka are explained by the structural features of the basin and valley. Melt water (since the river in the upper reaches flows from south to north) comes to Kaluga at the same time from the entire basin of the entire Upper Oka.

Viewpoint: Kama - the main river

The left tributary of the Volga is the Kama River. This seems to be an unshakable statement. But it turns out that it can be refuted. According to many hydrological characteristics, it is the Kama - main river, and the big Volga is its tributary. There is a number of “reinforced concrete” evidence for this. Firstly, where they merge, the Kama River carries 4300 m 3 /s, and the Volga is much less - 3100. It turns out that the Kama is more full-flowing. Secondly, the greater Volga has fewer tributaries - 66.5 thousand rivers, while the Kama - 73.7 thousand. Thirdly, geography is the surest sign of primacy, and the source of the Kama is geographically located higher.

Despite the fact that the Volga, although it flows for a very long time, it has a shorter path to the confluence. The most basic, fourth factor is age. The Kama Valley is much older than the Volga Valley. It existed even when the Volga did not exist at all. Therefore, Kama was unfairly offended when they called her a channel. But historically it turned out differently. And she is just the left tributary of the Volga, which is forever.

The largest tributary of the Volga - Eruslan

Eruslan begins in the Saratov region, at an altitude of approximately 100 meters, on the southern slopes of the General Syrt watershed, which are wide and gentle. This tributary of the Volga is the largest left-bank tributary within the boundaries of the Volgograd region. Its length is 273 km, 130 of which are in this area. The spread of the channel is from 10 to 50 meters, a big difference in depth - from tens of centimeters to three meters. The river level rises by 5-6 meters in spring, and the riverbed becomes shallower in summer. Annual average consumption water is 0.1-0.6 m 3 /s, it is used for irrigation of plantations and vegetable gardens. Small tributaries flow into Eruslan from the left: the White Kuba, the Salty Kuba, the drying up Torgui, as well as the drying up steppe river Kamyshevakha. We continue to study the tributaries of the river. Volga still has a lot of them in stock.

One of the most picturesque rivers of the Volga region - Sura

Sura is the right tributary of a large river. Its first name known to mankind is Rau, which means “river”. It changed several times and under the influence of the Russian, a well-known word, it turned into Sura. Sura is a tributary of the Volga, it flows through the Penza, Nizhny Novgorod and Ulyanovsk regions, Mari El, Mordovia and Chuvashia. 841 km is the length of the river, 67.5 thousand km 2 is the area of ​​the basin. It begins on the highlands of the Volga region, near the village of Surskie Vershiny, and flows to the west, and then mainly to the north. The Sura in its lower reaches is navigable and raftable, which allows it to be used for water supply to industry.

The mouth of the river is the Cheboksary Reservoir. Its diet is mixed, but most of all - snow. In April-May there is high water. It freezes, like most rivers in this region, in November-December, and opens at the end of March-April. There is a regulated flow after the construction of the Sur reservoir. The Sura is a tributary of the Volga, and it is also home to pike, asp, pike perch, bream, sterlet, catfish, silver bream, roach, crucian carp, sabrefish, bleak, sprat, ruffe, perch, and white-eye. And in the old days there were a lot of sterlet in these places.

What tributaries are located in the Saratov region

A tributary of the Volga in the Saratov region is the Samara River. It flows through the territories of Samara and Orenburg regions. Flows into big river From the left side. The city of the same name Samara is located at its mouth. By the way, there is another river with a similar name that flows through Ukraine and is a tributary of the Dnieper. The length of the river is 594 km. 46,500 km 2 - drainage basin area. It begins on the rise of General Syrt. It flows mainly in a northwesterly direction. Its valley is asymmetrical. The right banks are steep, the left banks are flat. 10-16 km - the width of the valley reaches these dimensions.

Samara flows into the reservoir of the same name. When it happens spring flood, the floodplain of the river is flooded and “Samara Venice” is formed, a land of channels and lakes. The river's floodplain is asymmetrical due to the valley, so only the left flat areas, covered with shrub and meadow vegetation, are flooded. Samara is located on the right high bank. The main tributaries of the river are the Bolshoi Kinel, Borovka, Buzuluk, Tok, Maly Uran, Bolshoi Uran. The ice lasts from early December until, as elsewhere here, April. The river is moderately polluted.

Economy of Volga tributaries

Large tributaries of the Volga are united by a common economy: hydropower, timber rafting, and transport shipping. Industry is highly developed here: gas and oil production, mining (mining of diamonds, rock salt, sodium, magnesium and potassium salts), mechanical engineering, chemical, metallurgical, automotive, pulp and paper and timber industries, production of building materials. The Kama is a tributary of the Volga, no worse than itself large river, and it greatly contributes to the development of those industries that require a lot of water.

Something, and this goodness is enough in her. Developed in these places and Agriculture: crop production, forestry, poultry farming, livestock farming, growing potatoes, grains. Huge spaces, a lot of moisture, rich nature - all this contributes to the development of the village. The Oka is a tributary of the Volga and has a very developed service sector. First of all, this concerns tourism and river cruises. These services have great prospects.

Other tributaries of the Volga

We will limit ourselves partially on this issue. In a short article it is impossible even to simply list all the tributaries of the river. The Volga is replenished with a considerable number of them. The following left tributaries are also known: the Big Karaman and the Small Irgiz. They do not have a constant flow and dry up by mid-summer, turning into a series of separate small lakes. When the dam of the Saratov hydroelectric power station was built, it became deeper here, and small ships sail in the lower reaches of the Irgiz. Kurdyum, Chardym and Tereshka flow into the Volga from the right. The last, largest of them, with a constant flow.

In the southeast of the Volga region the Maly Uzen and Bolshoy Uzen flow. In Kazakhstan, in the south, where they flow, they flow into the Kamysh-Samar lakes. The Saratov irrigation canal breathed into river valleys new life. The rivers of the Volga region are used to irrigate lands. The irrigation system and reservoir were built on the Tolstovka River, which flows into the Bolshoi Irgiz. The fields, vegetable plantations and gardens at the Pugachevsky state farm are irrigated from the Irgiz River. Water is supplied by a floating pump station.

The Volga originates on the Valdai Hills (height 228 meters), it flows into the Caspian Sea basin. The mouth of the river is located below ocean level - almost 28 meters, and the height of its total fall is 256 meters. In total, the Volga has 200 tributaries, the left ones of which are much richer and more numerous than the right ones. IN river system The Volga basin includes 151 thousand watercourses in the form of rivers, streams and temporary tributaries, the total length of which is 574 thousand kilometers. The river basin extends from the western (Central Russian and Valdai) hills to the eastern Urals.

At the Saratov latitude, the Volga basin narrows sharply and then flows from Kamyshin to the Caspian Sea with absolutely no tributaries. The main feeding part of the Volga river drainage area is the largest watercourse located in the forest zone extending to Kazan and Nizhny Novgorod. Through forest-steppe zone, extending to Saratov and Samara, flows the middle part of the giant Volga basin, and its lower part flows to Volgograd in the steppe zone.

Main tributaries of the Volga

The Volga is conventionally divided into upper, middle and lower parts. The upper flows from the source to the mouth of the Oka River, the middle - from the place where the Oka flows into it and to the mouth of the Kama, the lower - from the place where the Kama flows to the Caspian Sea basin. The largest tributaries of the Volga in its upper reaches are Selizharovka (length 36 kilometers), Darkness (length 142 kilometers), Tvertsa (length 188 kilometers), Mologa (length 456 kilometers), Sheksna (length 139 kilometers) and Unzha (length 426 kilometers) .

After the construction of the Kuibyshev reservoir, the border between the lower and middle Volga is the Zhigulevskaya hydroelectric power station.

The largest tributaries of the Volga in the middle reaches are the Sura (length 841 kilometers), Vetluga (length 889 kilometers) and Sviyaga (length 375 kilometers). In the lower reaches of the river flow such large tributaries as Sok (length 364 kilometers), Samara (length 594 kilometers), Bolshoy Irgiz (length 675 kilometers) and Eruslan (length 278 kilometers). In total, in the Volga River delta there are about 500 different tributaries, small rivulets and channels, the largest of which are the Old Volga, Kamyzyak, Bakhtemir, Akhtub, Buzan and Bolda. The river has enormous economic potential and irrigates many areas along its route that need additional recharge.

The Kama is the largest and most powerful tributary of the Volga. It ranks, after the Volga, second among the rivers of the European part of Russia in terms of drainage area (522,000 km 2) and length equal to 2,030 km.

The Kama originates within the Upper Kama Plateau, which is the northern part of the High Trans-Volga region. First, the river flows north, then turns east at a right angle and, having reached the foothills of the Urals, changes its direction again, sharply turning south. Thus, in the upper reaches of the Kama it forms a kind of giant loop. With a total length exceeding 2000 km, the distance from the source to the mouth in a straight line is about 445 km. This peculiar direction of the Kama flow and its sharp change are explained by the influence of glaciation, as a result of which the river network of the Kama basin was reshaped.

The Kama, like the Volga, is one of the lowland rivers; its average slope, however, is almost 2 times greater than the latter, but is also small and amounts to about 0.11°/oo. In the upper reaches of the Kama there is relatively little water. Only after the Vishera, which has a very high water content, flows into it, does the river really become full-flowing. From the mouth of the Vishera to the confluence of the next large tributary - the Chusovoy - the Kama flows mainly in a deep valley with high banks.

The water regime of the Kama is more complex than that of other lowland rivers of the European part of Russia. Its regime is significantly affected by the influence of left-bank mountain tributaries, which are distinguished not only by high relative water content, but also by a slightly different regime (significant and quite frequent summer rain floods (compared to other rivers of the basin. This is especially noticeable after the confluence of the Vishera.

The main role in the nutrition of the Kama River is played by melted snow water, the share of which in the total annual runoff exceeds 50%. Rain and ground nutrition is also significant. The main features of the water regime are the same as that of the Volga. However, the Kama is characterized by more unstable summer low water, often interrupted by rain floods, sometimes reaching significant strength. The amplitude of water level fluctuations reaches 10-12 m (near the town of Molotov). The river freezes in mid-November and opens in the second half of April.

The Kama receives a large number of tributaries, of which the most important are the Vishera, Chusovaya, Belaya and Vyatka; basic information about them is given in table. 1.

Table 1. Basic information about the main tributaries of the Kama

The Oka is the second largest tributary of the Volga, after the Kama. It originates in the center of the Central Russian Upland, at an altitude of 226 m above sea level. It flows into the Volga from the right, near the city of Gorky. The Oka basin (245,000 km 2) makes up 51% of the entire catchment area of ​​the Upper Volga. The length of the river is 1480 km. In general, this is a typical flat river of the European part of the country with an average slope of 0.11°/oo.

The main tributaries of the river are Moscow (length 502 km, basin area 17500 km2), Moksha (614 km, 50900 km2) and Klyazma (547 km, 42200 km2).

According to the nature of the valley and riverbed, the Oka is sharply divided into two parts: the upper - from the source to the confluence of the river. Moscow - and the lower one, covering the rest of the river. In its upper reaches, the river passes through the Central Russian Upland, where it has a deeply incised, predominantly narrow river valley and slopes that are quite significant for a flat river - from 0.2-0.3 to 1.0-3.0°/oo (in the most upper reaches).

Below the confluence of the river. Moscow Oka enters the region of the vast Oka Lowland (Meshchera Lowland), replete with swamps and lakes and reminiscent in its character of Belarusian Polesie. Its valley expands greatly, reaching 25-30 km in places in lake-like extensions. On the wide floodplain of the Oka there are numerous manes; the depressions between them are occupied by oxbow lakes.

The Oka basin is located in an area of ​​deciduous forests, where evaporation losses are significantly higher than in the Upper Volga basin, and only 73 of the precipitation goes to runoff. The average annual river water flow is 1200 m 3 /sec, and the corresponding flow module is 5 l/sec km 2.

The water regime is characterized by features common to rivers in the forest zone of the European part. A feature of the Oka regime is quite frequent and sometimes high summer and especially autumn floods; in some years they reach the size of the average spring flood. The Oka is characterized by large fluctuations in water levels, especially in the upper and middle reaches. A catastrophically high flood was observed in 1908, when the rise in level near the city of Kaluga reached 18.0 m. Such large fluctuations in the level on the upper Oka are largely explained by the structural features of the valley and basin. In the upper reaches, the river flows from south to north, and, as a consequence of this, melt water flows to Kaluga almost simultaneously from the entire upper Oka basin.

Economic use of waters of the Volga basin

Volga with her main tributaries- Okoye, Kamoy, etc. - has long played an important role in the national economy. Many of the rivers in its basin were primarily used as waterways for transporting grain, timber, oil, etc., as well as for passenger traffic. The total length of shipping routes in the Volga basin reaches 17,700 km, and rafting routes - 41,000 km: a disadvantage waterways is the presence of numerous shallow sandy rifts that impede navigation. To ensure navigable depths during low water periods, dredging work is carried out, and the volume of this work can be very significant; for example, in 1939, 28 dredgers were in operation, removing up to 12,000 m 3 of soil from the bottom of the rifts every day.

With the help of the Volga-Baltic (formerly Mariinskaya) system, the Volga basin is connected to the Baltic Sea. In 1937, the Moscow Canal, connecting the Volga with Moscow, was completed and opened for operation; this canal is one of the world's largest hydraulic structures. Its length is 128 km. It starts from the Volga near Ivankov, from here it goes to the city of Dmitrov and further to Moscow. It is powered by water supplied from the Volga by powerful pumps. In summer, up to 78 m 3 /sec is supplied to feed the canal, i.e. 5 times more than the river water flow. Moscow in low water. With the construction of the Moscow Canal, major tasks were resolved to create a deep-water route to Moscow, its water supply and water supply.

In terms of energy, the Volga was not used at all before the Great October Revolution. During the years of Stalin's five-year plans, three powerful hydroelectric power stations were built in its upper reaches: Ivankovskaya, Uglichskaya and Shcherbakovskaya.

Numerous water management problems associated with the Volga are combined into a common big problem - the problem of the Greater Volga. This problem includes:
1) use of the energy of the river and its tributaries,
2) creation of deep-sea transport routes,
3) construction of connecting waterways for communication with adjacent basins,
4) use of Volga waters for irrigation and water supply of the Trans-Volga region and the Caspian lowland.

Most of these problems will be resolved as a result of the implementation of the historic government decree on the construction of the Kuibyshev and Stalingrad hydroelectric power stations on the Volga and on the irrigation and water supply of the Caspian regions. The fifth five-year plan also plans to carry out the construction of the Cheboksary hydroelectric power station.

The Volga-Don Shipping Canal named after V.I. Lenin, built in 1952, which connected the Volga and Don basins in the area of ​​Stalingrad and Kalach, is extremely important for water transport. The length of the canal is 101 km. On its Volga slope a staircase of 9 locks was built, here ships rise to the watershed to a height of 88 m above the water level in the Volga; to the Don they descend to 44 m using 4 locks. There are a total of 13 locks on the canal.

Three large reservoirs were built along the Volga-Don Canal named after V.I. Lenin: Varvarovskoye, Bereslavskoye and Karpovskoye (the largest of them). Reservoirs are filled with water mainly through pumping units, supplying water from the Tsimlyansk reservoir located on the Don.

The economic importance of Kama is also very great. It is an important water transport route. Towing navigation on the river starts from the village. Kaygorodskoye (1572 km from the mouth). During low water, the river becomes very shallow, so navigable depths are maintained by dredging.

The Oka is navigable in the area from its mouth to the city of Kaluga. The presence of a large number of rifts (up to 250) in the middle and lower reaches is very unfavorable for navigation; navigable depths are maintained by dredging. Below the mouth of the river. In Moscow, two dams were built on the Oka to maintain navigable depths; a significant number of dams have also been built in its upper reaches. In connection with the creation of the Moscow Canal, which connected the river. Moscow (a tributary of the Oka) with the Volga, the shipping importance of the Oka has greatly increased. Projects are being developed to use energy and improve the river's navigable conditions.

In connection with the construction of large reservoirs in the Volga basin, the total area of ​​which will exceed 20,000 km 2, moisture losses due to evaporation will increase. As a result, the total flow of the Volga into the Caspian Sea will decrease by approximately 5 km 3 per year, i.e. by approximately 2%. This could lead to a decrease in sea level, which is already last years dropped a lot. The question arises about the possible transfer of water from other basins to maintain the level of the Caspian Sea. In particular, as one of the options, we mean the transfer of Ob waters to the sea (Ob-Aral-Caspian problem).