Interesting and necessary information about building materials and technologies. Economic use of the Lena River

On many rivers, navigation is carried out at depths determined by household costs. In the low-water period, with their decrease, there is a significant decrease in domestic depths, according to which the maximum allowable draft of ships is determined.

An increase in the minimum depths is possible in various ways, for example, deepening the bottom by dredging or removing thresholds on separate sections riverbed. Increase minimum depth allows you to increase the allowable draft of ships, their displacement; and, as a result, to reduce the required number of vessels providing a given cargo turnover.

The choice of the optimal navigable depth for a given section of the river is carried out on the basis of special technical and economic calculations.

For the safe movement of ships, a sufficient layer of water, a keel depth reserve located between the bottom of the ship in the place of its greatest draft and the bottom of the river are necessary.

The minimum margin under the bottom of the vessel ASC, depending on the characteristics of the soil, is assumed to be, m: for soft soils - 0.1; for rocky ones - 0.3. The increase in the draft of the vessel during movement, associated with the location of the propulsors in the stern, is about 0.035 Us (where Vc - maximum speed movement of the ship), i.e. approximately at a speed of 10 km / h. The depth margin per wave is assumed to be 0.3 hB if

For each of the considered values ​​of the navigable depth, the reduced costs are determined 3. They. are made up of the costs of providing the required depths and the costs of the river fleet associated with the replacement of the type and number of required vessels caused by a change in the navigable depth. Comparing several obtained depth values, choose the one at which the costs will be minimal.

As the cargo turnover on the section of the river under consideration increases, the costs of maintaining the navigable depth in the first approximation remain unchanged, and the costs for the fleet grow due to an increase in the number of vessels, fuel costs, etc. In fact, with an increase in the number of vessels used on this section of the river, the costs of maintaining the required navigable depth will also increase, as a reduction in the duration of the vessels will require the involvement of more dredging projectiles.

In this case, the optimal depth may change and become somewhat larger. Knowledge of the growth rate of cargo turnover in a given section of the river makes it possible to identify the dynamics of changes in the volume of dredging works

Table 16.1. Technical and economic characteristics of river cargo ships and the values ​​​​of the minimum navigational depth reserve and draw up a diagram perspective development water transport, i.e., to determine the necessary increase in navigable depths and the additional number of new river vessels of larger displacement and with greater draft.

On fig. 16.3 shows the dependence of the navigable depth on capital investments and annual costs in river fleet, as well as necessary to ensure the specified navigable depths and their maintenance during operation. For each specific case, these dependencies will be different, which is explained by dissimilar local conditions (geology, topography, width of the channel and navigable route, type of river vessels, etc.).

In Russia, most water flows are navigable rivers. One of them is Lena. In the world classification, it ranks 10th in length and 8th in full-flowing. Flows through Irkutsk region, Yakutia, Khabarovsk, Krasnoyarsk and Trans-Baikal Territories, Amur Region, as well as Buryatia. It is the most its entire basin is located on the territory Russian Federation. The length is 4 thousand km. It opens up from the upper reaches to the lower reaches, freezes in reverse order. It feeds on rain and melt water.

Source and mouth

Lena begins with a consideration of its beginning and end - the source and mouth.

The largest river in Siberia originates in a small swamp located on the Baikal Ridge. It is he who is officially considered the source. Its length is 300 km. A small area on its slope is occupied by pine forests, sometimes there is a forest-steppe, a little higher is the taiga. The woodland can be seen at an altitude of 1400 m. It is quite narrow here.

In the middle course, located in the area between the Aldan and Vitim (tributaries of the Lena), the watercourse expands and turns into deep river, the depth of which reaches 20 m. After the Vilyui flows into it, it turns into a fairly large stream. Here its width is more than 10 km (in some areas this figure is tripled).

In the lower reaches, flowing through various mountains and ranges, it flows into which is located in the north of Siberia and is named after the brothers Khariton and Dmitry Laptev. The climate on the sea is severe: it is constantly ice-bound (the exception is August and September).

Geography of the river

The economic use of the Lena River to a large extent depends on its geographical factors. The length of the stream is 4 thousand kilometers. The stream is divided into three different sections:

• First: from the source to Vitim.
• Second: from Vitim to Aldan.
• Third: from Aldan to the Laptev Sea.

Near the source of the Lena, which is located a few kilometers from Lake Baikal, a small chapel was built in the late 90s, attracting tourists from all over the country like a magnet.

In the second section of the course, the length of the river is 1415 km. All of it is located in Yakutia. By joining Vitim, Lena expands her territory. Here you can also find many small islands, some of which are mined for minerals. The valley increases up to 25 km. The left slope is gentle, while the right one is steeper and higher. Forests grow here, mostly coniferous, meadows are spread out. In the Pokrovsk area, the current calms down, the speed does not exceed 1.2 m/s.

The river becomes gigantic in the third section. Its width exceeds 20 km, depth - 20 m. The delta begins only 140 km from the Laptev Sea.

Hydrology. River characteristic

Lena is the only one in the region where there is an opportunity to extract minerals. There are unique complexes here.

A feature of this water flow can be called the fact that catastrophic floods occur in spring, often protracted. The river is fed by melt and rain waters, less often by groundwater. Floods and low water often occur on the river as well.

Often, the economic use of the Lena River depends precisely on the hydrological regime, which here sometimes shows far from the best sides.

In 1986, there was the maximum flow of the river to date: 402 km 3. On the this moment this figure has decreased several times. Moreover, it is constantly changing under the influence solar activity, or rather, its cycles.

The ice regime interferes with the economic use of the river. Ice jams often occur here, and it is quite strong and thick. In particular, it is for this reason that large areas are flooded during the spring thaw.

Infrastructure

The map of the Lena River shows all navigable areas, because it is the main water artery of Yakutia. Exactly given thread connects this region of the country with its neighbors. Northern delivery is carried out precisely along the Lena.

Kachug is the first navigable section, but only small vessels are found on the river just above it. Due to shallow water and potentially dangerous turns the territory of the water flow from Ust-Kut to the Vitim tributary is used minimally. This is what largely complicates the economic use of the Lena River. Every year, work is carried out here to deepen the bottom.

In addition to several ports, there are bridges on the stream. It is also planned to build a special railway crossing to facilitate the transportation of goods.

Economic use of the river

Lena gives her water settlements located on its banks. In addition, it is designed for fishing. Due to the fact that there are no dams on it, the fish breeds perfectly. The sturgeon is the most famous of the rare marine animals found here. Previously, this commercial fish grew up to 2 meters, but due to poor environmental situation the population dwindled. In addition to the sturgeon, other equally valuable species live in the Lena.

Fishing is the only use of the river by the population. The state does not build hydroelectric power stations and dams on it, so the main purpose of the watercourse can only be called the transportation of goods.

Navigable rivers of the country

The map of the Lena River is, of course, impressive. Its dimensions will not leave anyone indifferent. However, this is not the only water flow in the Russian Federation, which allows ships to move.

And although there is sometimes a sharp shortage of water transport throughout the country, 146,000 kilometers of routes have been established here.

The navigable rivers of Russia are scattered throughout our vast country. The main one is the Volga-Kama basin. Here, bread, oil, building materials are transported by water.

The most important arteries are:

Lena's main problem is her ecological condition. It worsens every year, which prevents optimal economic use. To a large extent, pollution is influenced by climate, discharge Wastewater and the movement of various vehicles. If the government of the Russian Federation does not decide this problem, then in a few years the population will lose the source of drinking water.

INLAND WATERWAYS, a set of navigable sections of rivers, lakes, reservoirs and canals. Important component transport and road complex of the country or mainland. In Russia, which has an extensive system of rivers, about 400 thousand km can be used for navigation, but due to a number of reasons (the direction of the flow of rivers, a mismatch with the direction of freight and passenger traffic, short physical navigation, difficult navigation and hydrological conditions), a little more 100 thousand km. In the history of the Russian state, GDP and river navigation have always played an important role. From ancient times, geographically separated river basins were connected by portage or horse-drawn roads, forming primitive transport networks that contributed to the formation centralized Russia. The state carried out work to improve waterways. "Dam masters" built dams, canals, which contributed to the development of industry. In the XVI century. in Moscow, a moat was dug around the Kremlin, 540 m long and 30–36 m wide. Water came from the river. Neglinnaya and was kept by dams with locks. In the city on the river. Yauza, Neglinnaya and others worked many "mills" (water engines). The Regulations (code of laws) adopted in 1649 affirmed the freedom of navigation: “And who will make a dam on such a river and make a gate for him to make a gate for that gate so that ships can walk through those gates.” The decree of Empress Catherine in December 1762 on the complete abolition of duties for passage through structures and supervision of its execution gave complete freedom to navigation. The emergence of St. Petersburg required the creation of transport links new capital with the Volga region. Grandiose projects for those times are put forward: the construction of the White Sea-Baltic and Volga-Don connections. Foreigners were attracted to carry out the canals, but this did not justify itself. Research and descriptions of waterways began. An important role was played by the works of M.V. Lomonosov. It was under him that extensive studies of the hydrological regime of rivers began for the first time. In 1809 the first hydrographic map of the European part of Russia was published. First success in improving waterways Russian state was created at the beginning of the eighteenth century. Vyshnevolotsk system. In her construction Active participation received a talented self-taught hydraulic engineer M.I. Serdyukov. In 1730, the construction of the canal from Novaya Ladoga to Shlisselburg was completed. On February 18, 1759, the Tsar's Decree "On the order of navigation on the Volga, Tvertsa and others" was issued. As well as European part Russia, studies of Siberian rivers are being carried out. In 1799–1801, the rivers were investigated. Angara, Ob, Lena. The development of the economy and transport required the centralization of the management of communications. In 1773, the post of chief director of water communications was established, to which the waterway from the mouth of the Klyazma to Tver and the Vyshnevolotsk system. The governor of the Novgorod, Tver and Pskov provinces, Yakov Efimovich Sivers, is appointed as the chief director. On February 28, 1798, the Department of Water Communications was established by royal decree under his own command. In the XIX-beginning of the XX centuries. intensive exploration of rivers continues along with the development of waterways and hydraulic engineering construction. In 1809, Emperor Alexander I signed the manifesto "Institution on the management of water and land communications" and the Institute of the Corps of Railway Engineers was opened. The Severo-Dvinskaya and Moskvoretskaya lock systems are put into operation, the Mariinskaya is being reconstructed. Later, the Okskaya, Tsninskaya, Seversko-Donetskaya systems were built. In the 1930s-1960s of the XX century. the development of energy gave impetus to hydrotechnical construction. In 1933 the White Sea-Baltic Canal was built, and in 1937 the unique Moscow-Volga Canal was built. In 1952, the dream of Peter I about the connection of the Volga and Don by navigation came true. Large energy complexes with navigation facilities are being built on the Volga, Kama, Ob, Yenisei, Lower Don, etc. Ensuring safe navigation conditions and reliable operation of hydraulic structures is a complex set of works. Their technical level reflects the level of development of many industries. Modern track facilities are multifaceted and include: works related to the operation of waterways (dredging, fencing of ship passages, straightening, bottom cleaning, trawling, surveys, bank protection, preparation of pilot charts, etc.); work related to the operation of shipping, etc. hydraulic structures on waterways (navigation, all types of repair of hydraulic structures, monitoring the state of hydraulic structures, adjacent territories and roads); water supply for a number of water consumers with the maintenance and operation of pumping stations; power generation with the maintenance and operation of small hydropower plants as part of water transport hydroelectric facilities; ship repair and shipbuilding technical and auxiliary fleet in repair shops; performance of construction works at hydroconstructions and other objects by economic means and by specialized subdivisions; maintenance and operation of the housing stock, as well as buildings for social and cultural purposes. During the work on the way to maintain navigable conditions, the general improvement of the rivers is carried out. The production of survey works, continuous surveys of rivers makes it possible to analyze the deformation of the channel over a long period. The appearance of reservoirs, the fleet's access to the bars of the Siberian rivers required the creation of large dredgers, which were built both at domestic enterprises and abroad. The waterworks required ships with diving equipment, special cranes; situational ships specially designed for various rivers and reservoirs were built. The total fleet of the railway fleet, including auxiliary vessels (floating cranes, firewalls, oil tankers and dry cargo vessels, tugboats, environmental vessels) is more than 3000 units. Navigational equipment on GDP also changed along with the development of technology. Today it is standardized. Buoys, buoys, alignments, cigars are built, as a rule, in the repair shops of railway organizations. In total, more than 160 thousand signs have been installed on the shores and afloat. About 1.5 thousand coastal signs are powered by coastal power networks. Lighting equipment operates in automatic mode. Navigable hydraulic structures are complex and multi-purpose, their significance is nationwide. They have a long service life, high book value, unique mechanical and electrical equipment. According to science-based standards, navigable hydraulic structures are considered as objects of "secular" use with a service life of 100 years or more. The maintenance of inland waterways is currently provided by 11 State Basin Administrations of Tracks and Navigation (GBUVPiS. now - the Administration of Inland Waterways Basins and Navigation) and the State Enterprise “Canal named after. Moscow" (now - FBU "Canal named after Moscow"). They have over 700 hydraulic structures on their balance sheet, incl. 110 locks, eight pumping stations, 11 hydroelectric power plants, 186 pressure dams and dams, 423 other structures. In 1996, the government of the Russian Federation approved the target program "Inland Waterways of Russia" with the status of a presidential one. It provides for the reconstruction of hydraulic structures, the maintenance and development of navigation equipment, the modernization and construction of the fleet, track facilities, the development and technical re-equipment of communications, scientific and technical support for program activities, the maintenance of inland waterways and technological communications. The program has established a list of navigable waterways classified as federal property. Government decrees provide for measures to improve the reliability of navigable hydraulic structures, ensure sustainable financing for their reconstruction and maintenance, introduce new technologies for repair and restoration work at hydraulic structures and navigational fencing of ship passages. 07/21/1997 adopted The federal law"On the safety of hydraulic structures". The provision of technical control is entrusted to the Russian River Register, which includes the Center for the Safety of Navigational Hydraulic Structures.

Russia has a dense river network. For navigation, 146 thousand km of waterways are used (USSR). Despite the shortcomings river transport compared to land, in some areas it plays decisive role. The advantages of river transport are especially noticeable in those areas where high-water rivers flow, and the creation of land transport requires large investments. Modern river vessels have a large carrying capacity and consume 6 times less energy per unit of transported cargo compared to the railway. Therefore, the transportation of bulk and bulk cargoes that do not require fast delivery along the rivers is beneficial: timber, oil, bread, building materials. The river routes of Russia, in connection with the meridional direction of the flow of most rivers, serve to communicate between the northern and southern regions: from the north comes the forest, and from the south - bread.

The navigable river routes belong to different basins. The main among them is the Volga-Kama basin, to which the economically developed part of the country gravitates. It is the core of the Unified deep-water system of the European part of Russia. This system provides navigation for large-capacity vessels with a draft of 3.5 m. The system includes: the White Sea-Baltic Canal, which shortened the route from White Sea to the Baltic by 4 times; the Moscow Canal, which gave the capital a deep-water outlet to the Volga and reduced the waterway to the cities of the North-West by 1,000 km; the Volga-Don Canal, which connected the Volga with the Black and Azov Seas; Volga-Baltic Canal - deep water route from the Bely and Baltic Seas to the Volga basin, thanks to it, ships from the Volga to St. Petersburg spend not 18, but 2.5 days.

Volga

Volga (ancient - Ra, in the Middle Ages - Itil), largest river in Europe - the area of ​​the basin is 1360 thousand sq. km. It originates in the Valdai Upland, flows into the Caspian Sea, forming a delta with an area of ​​19 thousand sq. km. km. The average water consumption near the city of Volgograd is 7240 m3/s. The Volga receives about 200 tributaries, the largest being the Kama and the Oka. In connection with the construction of a cascade of hydroelectric power stations with reservoirs, the flow of the Volga is heavily regulated. The largest hydroelectric power stations are Volzhskaya (Kuibyshevskaya), Volzhskaya (Volgogradskaya), Cheboksarskaya. The Volga connects with the Baltic m. Volga-Baltic by water, with the White m. - the North Dvina water system and the White Sea-Baltic Canal, with the Azov and Black Seas - the Volga-Don Shipping Canal, with Moscow - the Canal. Moscow. The following nature reserves are located in the Volga basin: Volzhsko-Kamsky, Zhigulevsky, Astrakhansky; natural national park Samarskaya Luka. As a result anthropogenic impacts the ecological situation has deteriorated sharply; a search is being made for scientifically based ways of restoring the natural complexes of the Volga.

Starting from the gentle hills of Valdai, the Volga collects water from a huge basin, which occupies almost a third of the Russian plain, and pours it into the Caspian. In length - 3688 km - the Volga ranks first among the rivers of Europe and surpasses all the rivers of the world that flow into inland waters. Full-flowing Volga tributaries serve as roads to the ridges of the Urals, dense forests of the North, to the fertile plains of the steppe zone. Among the many rivers flowing into the Volga are Tvertsa, Medveditsa, Mologa, Sheksna, Kostroma, Unzha, Oka, Kerzhenets, Sura, Vetluga, Sviyaga, Kama. The Kama is one of the most important river routes in our country; its length exceeds 2000 km. Slightly inferior to her Oka, stretching for almost 1500 km.

Fig.1. Volga river

Gardens, riverside quarters of Tver, Rybinsk, Yaroslavl, Kostroma, Nizhny Novgorod, Kazan, Ulyanovsk, Samara, Saratov, Volgograd, Astrakhan look into the Volga waters. Many thousands of years ago, fires of primitive man burned over the Volga waters. Rough boats, hollowed out or scorched from tree trunks, lay on the sand near the ancient settlements. Even in those distant times, different tribes moved along the river; Archaeological finds prove this. Ptolemy in the 2nd century AD mentioned the Volga, calling it the ancient name of Ra. Over the years, the importance of the mighty river has increased. Since the 8th century, it has become one of the main trade routes for a vast territory. The ancient chronicles tell how the Slavs-Russians descended down the Volga, fearlessly sailed across the Caspian Sea and penetrated with their goods far to the east, to fabulous Baghdad.

And in times Kievan Rus, and at a time when "Lord Veliky Novgorod" reached its peak, the ties of the Russian people with the Volga were strengthened. Cities were built on the banks of the Volga, arable lands were plowed up, and forest jungles were developed. When Kazan fell and Astrakhan surrendered, waterways to the Urals, fur-rich Siberia, the expanses of the Caspian Sea, and the countries of Central Asia. The never-before-seen caravans of 500-600 plows loaded with goods and guarded by archers were taken to their waters by the Volga, which became the main route of communication between Russia and the East. Gradually, the Volgars learned to build strong and light ships. Particularly distinguished among them were the bark that walked along the Volga from the 17th and even into the 19th century. In windy weather, sails were raised on them; and in the calm of the wind, the bark was pulled against the current by barge haulers, to whose hard work I.E. dedicated his famous painting. Repin.

In the Volga basin, there were up to 600 thousand barge haulers in the 20th century. Bargainism, generated by serfdom, remained a dark spot in the history of domestic shipping. But barge haulers were not only in the history of Russia. The labor of people for the movement of ships on a tow line was used in all European countries. The first steamboat in the Volga basin was built in 1816 by the craftsmen of the Pozhevsky plant on the Kama. In 1817 he went to the Volga. The Volga Shipping Company began to develop especially rapidly after the abolition of serfdom in Russia. On the Volga, for the first time in the world, the transportation of oil in bulk was widely used. Prior to this, oil was transported in wooden and metal barrels, which took up a lot of space in the ship's holds, which was both expensive and inconvenient. Following the oil tanker sailboats, the Volgars built the world's first iron oil tank barges "Elena" and "Elizaveta". The method of transporting oil in bulk, which in many countries was called the "Russian method", has spread to all the seas and oceans of the globe.

The Volga shipbuilding has overtaken the shipbuilding of the countries of Western Europe. It was on the Volga that the type of comfortable passenger ship was created, which has survived without significant changes to the present day. Early 20th century marked a very important event in global shipping. The Vandal oil tanker built by the Sormovo plant was equipped with internal combustion engines that ran on oil instead of kerosene. In 1903, this vessel, the world's first motor ship, set sail. On the next year was ready "Sarmat" - the second motor ship, significantly improved compared to the "Vandal". Then the world's first towing ship "Thought", the passenger wheeled ship "Ural" and, finally, the famous screw ship "Borodino" went along the Volga.

Until the beginning of the 20th century. in the height of summer on the Volga, due to shallow water, the movement of steamers above Rybinsk stopped; near Kostroma and Yaroslavl it was possible to find fords. Near some Volga rifts in low water ( middle level water after the flood) sometimes accumulated several dozen ships. Even after the significant dredging work carried out on the Volga before the First World War, the "main street of Russia" still remained in a rather neglected state. There were no specially equipped river ports on it either. Warehouses and storehouses along the shore, shaky footbridges, on which, bending under the excessive weight of bales and boxes, loaders, or, as they were called, hookers, walked in a row - this is a picture of the old Volga wharf. Already in the first years of the existence of the USSR, changes began on the great river. In the pre-war years, after the construction of the White Sea Canal, the Volga received access to the North Polar Basin, the Volga-Moscow Canal connected it with the capital.

The plan for further work on the great river, developed at the direction of the Party and the government, was called the Big Volga plan. This plan provided for a radical reconstruction of the river, its best use. The problem was solved comprehensively, in such a way that at the same time navigation conditions were improved, the transport links of the Volga with the seas and the main river basins of the European part of the country were strengthened and developed, so that the built hydroelectric power station would provide the national economy with cheap energy, and the Volga water would be used for irrigation and watering the land.

The Big Volga Cascade includes, first of all, eight main waterworks: Ivankovsky, Uglichsky, Rybinsky, Gorky, Cheboksary, Kuibyshevsky, Saratovsky, Volgogradsky. The scheme of the Great Volga also provided for the construction of hydropower facilities on the Volga tributaries - the Kama, Oka, Vetluga, and Sura. In two decades, the connection of the Volga basin with all the seas washing the European part of the country was completed to turn the Volga into a highway of five seas: the White, Baltic, Caspian, Azov and Black. This work began with surveys on the route of the White Sea-Baltic Canal in 1931 and ended with the first voyage of Volga ships along the Volga-Don Canal in the summer of 1952. And in 1964, the construction of the deep-water Volga-Baltic Canal was completed.

Kama

Whoever has not seen the forests there, has not admired the Kama and Chusovaya, has not breathed the air that the local lakes intoxicate in the summer, he does not know the beauties of nature "- wrote about the Kama region, the singer of the Urals, D.N. Mamin - Siberian. I recall the paintings of Shishkin, Maximov, Meshkov's painting "The open spaces of the Kama", where lilac fogs float above the steely water, and mighty firs rose along the coastal steeps ... The Kama is the fifth longest river of the European continent: only the Volga, Danube, Ural and Dnieper are longer than it. The Kama describes a giant arc more than two thousand kilometers from Kazan to the Udmurt village of Karpushata, where on the gentle slopes of the "Ageevsky Log" the first jets of Kama are born from the springs, only four hundred kilometers.

Almost in the same place, the tributary of the Kama - the Vyatka - begins. At first, Vyatka and Kama flow in parallel - to the north, then they diverge, and before connecting their waters, separated at the sources by a narrow wooded ridge, they run a long way. In the upper reaches the channel is unstable and winding, below the mouth of the Vishera there is a deep river. The flow of the Kama is regulated for a considerable distance by the dams of the Kama, Votkinsk and Nizhnekamsk hydroelectric power stations, above which reservoirs have been created. At the confluence with the Volga is the Volga-Kama Reserve. Major cities: Solikamsk, Berezniki, Perm, Krasnoarmeysk, Sarapul, Naberezhnye Chelny, Chistopol.

Fig.2. The Kama River near Gremyachevo

The total length of the Kama is 2030 km. It collects water from the expanses of the pool, covering an area of ​​522 thousand square meters. km - slightly inferior to France. It is replete with moisture-storing forests and swamps, mountain springs and rivers. More than two hundred significant tributaries are received by the Kama and, in terms of high water, it is just right for it to compete with the Volga; here are the largest of them: Vishera, Chusovaya, Belaya, Vyatka. The nature of the Kama basin is diverse. Here are the slopes of the Ural Range, and the ancient plateaus, and low plains. Coniferous forests similar to Siberian taiga, surround the banks of the Kama in the upper reaches; in the lower reaches, oak groves and lush green lindens are reflected in its waters.

Since ancient times, Kama has been the main trade route for the peoples who inhabited its shores. Already at 11 in the Russian boats appeared here. Along the Kama and its tributary, the Chusovaya, Yermak's squad went to Siberia, showing the way to many brave explorers - and since then mighty river connected Muscovite Russia with Siberia. The wealth of the Kama basin is incalculable. More than 12 thousand mineral deposits have been discovered in the Urals, and a large proportion of them are in the Kama basin. In the river basin, forests cover about 14 million hectares. Most of all ate here, larches, firs, pines. The industry of the Kama region is represented by ferrous and non-ferrous metallurgy, oil and coal industries, machine-building, metalworking, and chemical enterprises.

At Nizhny Novgorod The Oka, its second largest tributary, flows into the Volga. The Oka originates in the Central Russian Upland, four kilometers from the village of Maloarkhangelsk. The length of the river from its source to Nizhny Novgorod is 1478 km. According to hydrological data and the nature of the path, the Oka is divided into three sections: upper middle and lower. Upper Oka - from the city of Aleksin to Shchurovo. Middle Oka - from Shchurovo (the mouth of the Moskva River) to the mouth of the Moksha River. It differs sharply from the upper section - the slopes decrease, the river becomes more abundant. The predominant direction is southeast. For 100 km, the section of the Shchurovo - Kuzminsk river is a lock. Here, in 1913-194, two hydroelectric facilities were built - Beloomutsky (63 km from Kolomna) and Kuzminsky - (43 km from Beloomut). Nizhnyaya Oka - from the mouth of the Moksha River to Nizhny Novgorod. The valley of the lower Oka is characterized by frequent narrowing and widening of the channel from one to two kilometers.

Fig.3. View of the Oka in the village of Konstantinovo, Ryazan region

The right bank from Pavlov to Gorky is high, the left bank from Murom to Nizhny Novgorod is low. On the slopes of the Oka, it approaches the middle and even lower reaches of the Volga. The climate of the river basin is temperate continental, uniform throughout. Winds prevail in summer western direction. on the banks of the Oka on the one hand - cliffs, on the other - the vast expanses of water meadows. Closer to the confluence of the Volga, near Nizhny Novgorod, the Oka becomes full of water, it darkens on the banks coniferous forests and copses.

Main tributaries: Ugra, Moscow, Klyazma, Moksha. High water from April to May in the upper reaches, and until the beginning of June - in the lower reaches; rain floods in autumn. Freezing in the upper reaches - from the beginning of January to the end of March - April; in the lower reaches - from December to early May. On the left bank in the middle reaches - the Prioksky Reserve. The river is navigable from the city of Chekalin, regular navigation - from the city of Serpukhov. Transit shipping - from the mouth of the Moscow River to the confluence of the Volga. On the Oka there are cities: Oryol, Kaluga, Serpukhov, Kashira, Kolomna, Ryazan, Kasimov, Murom, Pavlovo, Dzerzhinsk, Nizhny Novgorod.

Don begins on the Central Russian Upland. Once it originated in Ivan Lake. Later, Ivan-lake began to give water to the sources of the Don only in early spring in high-water years. In ordinary years, the upper reaches were fed mainly by the Urvanka River. She was considered the source of the Don. But at present, Ivan-lake does not exist at all. In its place, the Shatsky reservoir, created near the city of Stalinogorsk, overflowed. The length of the Don is about 1970 km. Its basin exceeds 440 thousand square meters. km. In summer, the Don was quite navigable only in the lower reaches. This happened because the river has an unusually unstable character. In the spring of a high-water year, the Don carries 170 times more water than in the summer of a dry year. Spring water rolls down the river in two waves: First, it comes from the southern tributaries, where spring comes earlier, and then it is sent from the northern ones. Sometimes both flood waves passed simultaneously, and then the Don overflowed especially strongly.

Fig.4. The Don River in the Voronezh Region

But the spring waters, given to the Don by thousands of small streams and rivers of its basin, rushed along the Don, the earth on the hillocks dried up, and the Don immediately changed. Calmly, unhurriedly, it flowed among the sandbars and shoals, washing the foothills of the white chalk hills, splitting into arms in wide patches. Even small steamboats could not sail in the middle reaches of the river. In the lower reaches of the Don, dredging machines were constantly working, barely managing to deepen the rifts and shoals that the river piled up. But the Don crosses important economic terms areas that need to be served by uninterruptedly operating water transport throughout the navigation.

Without a serious change in the water regime, the Don could not become a transit route for large ships between the Volga basin and the Black Sea. Therefore, the construction of the Volga-Don Canal and the reconstruction of the river represented single complex works. The rational distribution of the water wealth of the Don is now carried out with the help of the Tsimlyansk Sea, which is blocked by a dam. The upper reaches of the Don remained aloof from the big waterway.

Don flows into the Taganrog Bay Sea of ​​Azov, forming a delta with an area of ​​340 sq. km. For a considerable distance, the river valley follows the steep eastern edge of the Central Russian Upland. Small slopes in the lower reaches provide a very slow current. Main tributaries: Khoper, Medveditsa, Sal, Seversky Donets. On the Don - the Tsimlyanskaya hydroelectric power station and a reservoir, the Nikolaevsky, Konstantinovsky and Kochetkovsky hydroelectric facilities. Navigation - from the mouth of the river. Pine (1604 km), regular navigation - from the city of Georgiou-Dezh (1355 km). In the Don basin there is a nature reserve Galichya Gora. Largest cities: Georgiou-Dezh, Kalach-on-Don, Rostov-on-Don, Azov, Volgodonsk.