Connecting the oceans. Great shipping canals. The largest shipping canals in the world

Types of shipping channels. Features of navigation on canals.

A canal is an artificial open water conduit in an earthen excavation or embankment. According to their purpose, channels are divided into connecting, bypass and approach.

Rice. 37. Emergency gates on canals

Connecting canals serve to connect rivers of different basins by water, as well as to connect rivers, lakes and seas (for example, the Moscow Canal, the Volga-Don Canal named after V.I. Lenin, the White Sea-Baltic Canal, etc.).

Bypass canals are designed for ships to bypass lakes where there are strong storms, as well as the central parts of large cities, etc. (such canals include the Ladoga, Prionezh, etc.).

Approach channels are an artificial deepening of a reservoir or watercourse along a ship's course, which has navigational signs. Approach canals serve mainly for the approach of ships from the main waterway to ports, settlements and industrial enterprises located away from the river (for example, canals in Arkhangelsk, Leningrad, Seymovsky on the Oka River, etc.).

According to the method of feeding, the canals are either gravity-fed or artificially fed.

Gravity canals receive water directly from the river or, lake and itself spreads throughout the channel. Such channels are the simplest and cheapest to operate.

In artificially fed canals, water from the source is pumped into the watershed pool, from where it flows by gravity. For example, on the Volga-Don Canal named after V.I. Lenin, three pumping stations were built with three powerful pumps, each of which pumps 15 m 3 of water in 1 second.

The hydraulic structures required for the operation of the canal mainly include navigation locks, emergency gates, emergency spillways and water outlets.

Locks on canals are used to allow ships to pass from one tail to another.

Emergency gates are used to shut down certain sections of the canal in the event of an emergency or for repairs. Emergency gates (Fig. 37) consist of the following main parts: abutments 1, gate 2, downward 6, flutbeta 5, water part 3 s energy absorbers 4. Gates are made in the form of rotary trusses or in the form of sliding gates, consisting of two panels.

Emergency spillways are designed to release water from the canal in case of overflow. They are usually a side spillway in a canal dam. The spillway level must be no lower than the forced level.

The drains are used to empty the canals; These are pipes laid in dams below the water level.

The main cross-sectional shapes of shipping channels are hollow-shaped, rectangular, trapezoidal and polygonal.

If few ships should pass through the canal and they will go mainly along its axis, using the greatest depths, a hollow-shaped canal is used (Fig. 38, c). During intense traffic, when ships meet every now and then, overtake each other and most of them move over slopes, the hollow-shaped shape is inconvenient - it increases the danger for the vessel to hit the slope.

In this regard, the best is rectangular (Fig. 38, b), a then the trapezoidal (Fig. 38, e) shape of the channel section. The first is rare, since the construction of vertical walls is very difficult and expensive. With a trapezoidal shape, a particularly strong sloughing of the slopes is observed.

Modern shipping canals have a predominantly polygonal (Fig. 38, d) cross-sectional shape. The bottom of such channels is horizontal, and the slopes have different steepness, depending on the type of soil. At the same time, the upper part is steeper, the lower part is flatter.

Depending on the position relative to the surface of the earth, the Canal can be in a excavation (Fig. 39, a), in a half-excavation and half-embankment (Fig. 39, b) and in an embankment (Fig. 39, b). An anti-seepage layer of clay is usually placed in the embankment.

Fastening the slopes of canals is necessary to protect them from destruction under the influence of ship waves, water flow, ice, ship impacts, etc. The most commonly used fastenings of slopes are in the form of a bridge or rock fill on a layer of crushed stone or gravel. Recently, fastening slopes with reinforced concrete and concrete slabs, as well as tongue and groove, has been widely used.

For shipping, the value of the profile coefficient is of great importance P, equal to the ratio of the open cross-section of the channel to the area of the immersed part of the ship's midsection % at full draft:

The more P, the less resistance of water to the movement of the vessel. For large modern channels the value P = 4 - 5,5.

The rounding of the channels is done with the largest possible radius, which should be more than 5-6 lengths of the largest vessel. In special cases, the radius of curvature can be reduced to three ship lengths (but not less), while the channel is expanded.

Ship waves, running onto the slopes of the canal, destroy them. The wave has a strong dynamic effect on both. Some of the water flows from the slope back into the canal, and some penetrates inside the slope, and, seeping down, erodes the base of the slope. The height of the wave depends on the size of the vessel and the speed of its movement and reaches 1.3 m. The approach of vessels to the shore leads to an increase in the height of the wave approaching the slope. Therefore, if possible, ships should move along the axis of the channel,

The stream of water thrown by the propellers has a great influence on the slopes and the bottom of the canal, especially when the ship is moving near the slope in a bend in the canal or drifting in the wind. Deformation of the slopes also occurs due to the resulting flow when the living cross-section of the channel is constrained by the ship's hull.

Due to the above reasons, the stone blind area of the slope collapses and slides, and navigable depths decrease.

The speed of ships on the canals is limited and does not exceed 12-15 km/h.

Dumping garbage and slag into the canal is prohibited. The release of anchors is possible only in designated areas; the use of lots and drag chains is not permitted.

Navigation along the canal is complicated by the small dimensions of the ship's passage, the presence of emergency and barrier gates, ferry crossings, locks and other structures. In addition, during operation of pumping stations, currents arise that can cause the vessel to yaw.

Sea shipping canals are an artificial route for connecting two sea basins or for the approach of ships to ports. They can be open or gated.

Open channels are the most common, they include all approach channels passing through land, estuary channels or the sea and being surface or representing an underwater artificial slot.

Open channels may be unfenced or enclosed by paired or single dams. Enclosed channels are less exposed to wave action and are less likely to carry sediment.

Marine approach channels are Arkhangelsk (delta arm,) Dnieper-Bug (bar), Kherson (estuary, arm and river), Volga-Caspian (delta arm), Leningrad, Zhdanovsky, Kaliningrad (sea bay), etc. Total length sea access channels in the USSR exceed 1000 km.

Channel- an artificial channel designed to shorten water routes or to redirect the flow of water.

The first irrigation canals appeared at the end of the 6th millennium BC. in Mesopotamia. Around the same time, apparently, they began to build irrigation systems in Ancient Egypt, so that by the turn of the 20th and 2000s a wide network of irrigation canals had been created in both countries. It is possible that the world's first shipping canal appeared in Ancient Egypt, which connected the Red Sea with the Mediterranean through one of the tributaries of the Nile. The construction of this waterway began around 600 BC. and continued until 518 BC, when the country was captured by the Persians.

According to the method of water supply, channels are divided into gravity channels, in which water flows under the influence of gravity, and with mechanical lifting of water, for which pumping stations are used.

According to their functions, modern channels are divided into two main types:

channels used for – delivery or drainage of water;
channels performing transport functions(for example, delivery of goods or people).

Often channels perform both functions.

Depending on their purpose, channels are divided into several types.

Since ancient times, reclamation canals have played an important role in agriculture, which, in turn, are divided into irrigation and drainage (drainage). The first of them deliver water and distribute it on the fields, so most often they can be found in the deserts and semi-deserts of Asia and Africa, as well as in areas where intensive farming is carried out. The latter, on the contrary, drain water from the wetland. Irrigation canals usually form a system of canals: main, distribution, irrigation and drainage. In large irrigation systems, main canals reach a length of several hundred km, for example, the Bolshoi Stavropol (over 300 km), the Bolshoi Fergana (about 300 km), and the Karakum Canal (796 km to Ashgabat).

Irrigation canals supply water for agricultural needs (mainly livestock) to waterless and arid areas; increase the flow of local small rivers and improve their sanitary condition.

Water canals supply water to the place of its consumption, and operating conditions and sanitary requirements often force such structures to be closed. Their main purpose is to supply water to waterless and arid areas from places where there is a constant surplus of water.

Water supply, water supply and irrigation canals can be gravity and machine.

Another type of channel is energy. Energy canals supply water from a river, reservoir, or lake to a hydroelectric power station or remove waste water from it. Energy channels are characterized by a relatively short length (usually not exceeding 5–10 km) and low throughput.

Shipping canals - freshwater and sea - connect rivers, lakes and seas and are usually designed for various types of water transport - from small boats to huge bulk carriers. The purpose of creating a shipping canal is to connect the basins of two reservoirs, shorten the path between two reservoirs, ensure guaranteed navigation, solve the problem of transport accessibility along the waterways of destinations, and create economically viable transportation routes.

Shipping canals (artificial waterways) can connect navigable rivers and seas (White Sea-Baltic Canal); can be carried out bypassing turbulent sections of large open bodies of water, for example lakes and seas (Onega, Priladozhskie, Belozersky, Beregovoi Mexican canals, etc.) or bypassing rapids sections of rivers; can straighten winding sections of the river to reduce the length of the waterway (Khoroshevsky Canal on the Moscow River, canal on the Don River below the Tsimlyanskaya Hydroelectric Power Station, etc.); can serve as navigable approaches from the sea, lake or river to populated areas, inland ports, industrial enterprises, agricultural areas (St. Petersburg and Volga-Caspian sea canals, etc.). Bypass, straightening and approach channels are usually built open (non-locked). Almost all connecting canals are lockable, due to the difference in levels in the connected rivers (sea), as well as due to the need to reduce the volume of excavation work when constructing canals across watersheds. Water is supplied to the shipping canals by gravity. Coastal lining is used to protect them from destruction by waves resulting from the movement of ships. The most famous lock canals are the Panama and Kiel canals.

Fish channels are built to supply water to spawning grounds, to allow fish to pass by bypassing hydraulic structures, to connect individual isolated reservoirs with fish to the river, etc.

Timber rafting canals are used for rafting timber or rafts from harvesting sites to a rafting river or sawmill, for transporting wood bypassing hydraulic structures.

Complex channels are built in order to comprehensively solve several economic problems. For example, the Volga-Don Canal named after. IN AND. Lenina (with the Tsimlyanskaya hydroelectric station) – a shipping-irrigation-energy complex.

The main characteristics of the channel are the shape and size of its live section, i.e. flow cross section.

According to the shape of the living cross-section of the channel, they are divided into the following varieties: trapezoidal, polygonal, rectangular, semicircular, parabolic, outlined by a more complex curve or composite.

From a hydraulic point of view, the semicircular shape is the most advantageous, but due to the difficulty of creating and preserving curved outlines in nature, semicircular and parabolic shapes are used very rarely.

A rectangular section is carried out when constructing channels in rock excavations, and in soft soils - in special cases (in populated areas, on slopes, etc.) by erecting retaining walls.

In cross section, the channels have a rectangular, trapezoidal and polygonal (multifaceted) shape.

Ice cover reduces the channel's capacity. To prevent the appearance of slush (bottom ice) in the channel, measures are taken to obtain surface ice of small thickness. If there is an inevitable large amount of slush, structures are provided to discharge it from the canal, and the canal itself is routed with a minimum number of turns.

To protect the canal bed from destruction by currents and waves, reduce water losses due to filtration into the ground and reduce the roughness of the open section (to increase the channel's throughput), linings are used. Facings that serve only to protect slopes from erosion are made in the form of stone paving, stone laying and riprap, as well as concrete slabs.

On all canals, except for special structures related to the operation of the canal (locks on shipping canals, pumping stations on machine canals, spillways, etc.), various structures are erected at the intersections of the canal with watercourses (pipes, siphons, aqueducts), with communication routes (viaducts, tunnels, bridges, pipes, ferry crossings, etc.) and in places of sharp changes in the terrain (changes, fast currents).

The construction of canals almost always requires the installation of additional structures, which can be divided into several categories:

water supply structures;
connecting structures;
structures regulating the general mode of the canal.

Water supply structures can replace individual sections of canals for both economic and technical reasons. Such structures include flumes, pipes, tunnels, aqueducts, siphons, mud flows, etc.

In cases where ground conditions do not allow for the establishment of a reliable canal bed, or the terrain where the section of the canal route passes is too complex (rugged terrain, mountain slopes, etc.), it is advisable to use trays. The flumes are also artificial channels, but they are located on the surface of the earth or are arranged above the ground on supports. They can be made of wood, reinforced concrete, metal and other materials. The movement of water in the trays is free-flowing. Sometimes the trays are protected on top with some kind of coating, which makes them closer in nature to pipes.

Aqueducts are installed where the canal crosses any obstacle: a river, ravine, road, etc. An aqueduct, unlike a flume on supports, is a permanent structure. In this regard, aqueducts are closer to bridges, while the tray itself can serve as a span structure.

Pipelines allow canal water to pass under any obstacle, and are also used in unfavorable climatic conditions in certain sections of the canal. Pipelines can be located either underground or open with direct access. The mode of water movement in pipelines is usually pressure.

If it is necessary to pass any watercourse under the canal, it is possible to install culverts. The design and calculations of such pipes are similar to the pipes used when crossing watercourses with embankments of roads and railways.

With a large slope of the terrain, water velocities in the canal can reach unacceptable values. In this regard, it is necessary to arrange sections of canals with differences in height. To connect such sections, interfacing structures are used, which generally include fast currents and drops.

During drops, water moves part of the way along the structure, and part of the way falls. In stepped drops, the energy of falling water is extinguished by special devices. In cantilever drops, falling water forms a funnel at the point of impact, which gradually reaches such a depth that erosion stops and the energy of the fall is completely extinguished.

Fast currents are trays with large slopes in which water moves at a speed greater than the critical one. The speed, however, should not reach the values allowed for the material of the bottom and walls. To reduce the speed, it is possible to use increased roughness of the tray in the form of various protrusions, steps and thresholds. At the end of the fast flow, water wells are installed to dampen the speed.

Pumping stations are also used to connect sections of channels of different heights.

Such structures that regulate the general mode of the canal include sluice-regulators and water dividers, emergency barriers, spillways and spillways, and slurry discharges.

A sluice-regulator is a dam equipped with gates. Its functions include regulation of water flow in the channel itself, as well as in branches from it. Emergency barriers are thresholds equipped with gates. If necessary, they can be used to isolate individual sections of the channel.

Yu.V. Bogatyreva, A.A. Belyakov

Sailors have been using man-made canals since Mesopotamian times. Let's take a look together at 5 famous historical canals located around the world.

Panama Canal – Panama

Construction of the canal began in 1904 and was completed in 1914.
Total length: 77 km (48 miles).
Connects the Atlantic Ocean and the Pacific Ocean.
Cost: $375 million.

The Panama Canal is a shipping canal connecting the Pacific Gulf of Panama with the Caribbean Sea and the Atlantic Ocean, located on the Isthmus of Panama in the state of Panama. Length - 81.6 km, including 65.2 km on land and 16.4 km along the bottom of the Panama and Limon bays (for the passage of ships to deep water).

The construction of the Panama Canal was one of the largest and most complex construction projects undertaken by mankind. The Panama Canal had an invaluable influence on the development of shipping and the economy as a whole in the Western Hemisphere and throughout the Earth, which determined its extremely high geopolitical significance. Thanks to the Panama Canal, the sea route from New York to San Francisco was reduced from 22.5 thousand km to 9.5 thousand km.

The canal accommodates all types of vessels, from private yachts to huge tankers and container ships. The maximum size of a ship that can transit the Panama Canal has become a de facto standard in shipbuilding, called Panamax.

Vessels are guided through the Panama Canal by the Panama Canal Pilot Service. The average time for a ship to pass through the canal is 9 hours, the minimum is 4 hours 10 minutes. Maximum throughput is 48 vessels per day.

Three years before the canal's centenary, on September 4, 2010, the millionth ship, the Chinese bulk carrier Fortune Plum, passed through the Panama Canal with a cargo of 40,000 tons of steel, heading from the Pacific to the Atlantic Ocean. Since the canal opened, 1 million ships have passed through it, accounting for 5% of global trade each year.

A year ago, work began to widen the canal by building a third track to accommodate the giant modern container ships, cruise ships and tankers, many of which are now too wide for the canal. The work was estimated at about $5.2 billion and is scheduled for completion in August 2014, in time for the canal's 100th anniversary.

The third passage, parallel to the previous two, will be able to accommodate massive vessels up to 366 m in length, 49 m in width and 15 m in draft. The canal's goal is to double cargo capacity from 300 to 600 million tons.

Erie Canal - New York

Construction of the canal began in 1817 and was completed in 1825.
Total length: 584 km (363 miles).
Connects Lake Erie with the river. Hudson, New York.
Cost: $7 million.

The Erie Canal is the main component of the New York State Barge Canal, a system of canalized waterways in the northeast. USA, in the state of New York. E.-k. connects the Great Lakes system with the Atlantic Ocean through the river. Hudson. Length from Buffalo to Lake. Erie to the city of Cohos at the confluence of the canalized river. Mohawk in the river Hudson over 540 km, width 50 m. On the E.-K. 35 locks up to 94.5 m long, 13.2 m wide and 3.6 m deep. Cargo turnover is about 4 million tons (oil and oil products, building materials, grain). Built in 1817-25; It was reconstructed several times (last time in 1905–18). In the middle of the 19th century. played an outstanding role in the development of the interior of the United States.

Suez Canal - Egypt

Construction of the canal began on April 25, 1859, and the opening took place on November 17, 1869.
Total length: 193.3 km (120.11 mi).
Connects the Mediterranean Sea and the Red Sea.
Cost: 560 million francs.

The Suez Canal is a navigable lockless canal in Egypt connecting the Mediterranean and Red Seas. The canal zone is considered a conditional border between two continents. The shortest waterway between the Indian and Atlantic Oceans (an alternative route is 8 thousand km longer). Main ports: Port Said and Suez.

Located west of the Sinai Peninsula, it is 163 kilometers long. The canal is located in Egypt between Port Said on the Mediterranean Sea and Suez on the Red Sea. On the eastern side of the canal opposite Port Said is Port Fuad, where the Suez Canal Authority is located. On the eastern side of the canal opposite Suez is Port Tawfik.

The canal allows water transport to pass in both directions between Europe and Asia without going around Africa. Before the opening of the canal, transportation was carried out by unloading ships and overland transport between the Mediterranean and Red Seas.

The canal consists of two parts - north and south of the Great Bitter Lake, connecting the Mediterranean Sea with the Gulf of Suez on the Red Sea.

Today it is the main budget-generating project in Egypt. According to some experts, the canal gives the country even more money than oil production, and much more than the rapidly developing tourism infrastructure in the country currently allows.

Royal Canal - Ireland

Construction of the canal began in 1790 and opened in 1817.
Total length: 145 km (90 miles).
Connects Dublin with the River Shannon at Clundara.
Cost: £1,421,954.

The King's Canal was originally built to carry freight and passenger traffic from the River Liffey in Dublin to the River Shannon at Clundara in Ireland. The canal was abandoned, but was later restored for navigation. The full length of the canal was reopened to ship traffic on October 1, 2010.

Grand Canal - China

Construction of the canal began in the 5th century.
Total length: 1,776 km (1,103 miles).
Connects Beijing and Gangzhou, China.
Cost: unknown.

The Grand Canal is a shipping canal in China, one of the oldest existing hydraulic structures in the world. It was built over two thousand years - from the 6th century. BC. until the 13th century AD Currently, it is one of the most important inland waterways of the People's Republic of China, connecting the country's major ports of Shanghai and Tianjin. The length of the canal is 1,782 km, and with branches to Beijing, Hangzhou and Nantong - 2,470 km. The width at the narrowest part in the provinces of Shandong and Hebei is 40 m, at the widest part in Shanghai - 3500 m. The depth of the fairway is from 2 to 3 m. The canal is equipped with 21 locks. The maximum carrying capacity is 10 million tons per year.

The canal connects the Yellow and Yangtze rivers, including the beds of rivers such as Baihe, Weihe, Sishui and others, as well as several lakes.

The Grand Canal consists of several sections built at different times. The southernmost section was laid in the 7th century, the northernmost in the 13th century, and part of the central section from Huaiyin to Jiangdu runs along the ancient Hangou Canal.

GRAND CANAL(Chinese - Yunho or Yunhe), a canal in China with a length of 1930 km, runs through the eastern part of the country in a general direction from north to south between the cities of Beijing and Hangzhou. This oldest and longest canal in the world crosses four provinces (Hebei, Shandong, Jiangsu and Zhejiang) and two great rivers - the Yellow River and the Yangtze. When the construction of this artificial conduit was completed (which took about 2,000 years), it became an important transport artery between the north and south of China.

The Grand Canal was built over three historical periods. Its oldest section, 225 km long, began to be built at the last stage of the existence of the Zhou state, presumably in the 6th century. BC. They connected the Yangtze River with the Huaihe River basin. Corresponding to this old canal, the section of the modern Grand Canal runs from the city of Qinjiang (in Jiangsu province) to the Yangtze River (in the Yangzhou region), passing through a series of lakes included in the Huaihe River basin. The water level in this region is regulated by dams, and small ships could navigate the canal here.

Let's find out more about it...

Photo 2.

Clickable

Almost everything rivers of China flow from west to east and empty into the Pacific Ocean. Therefore, already in ancient times, a system of canals arose that connected the basins of these rivers. Subsequently, the individual sections were combined and completed. This is how it appeared Great Chinese Canal, or as it is called in China, Grand Canal(大运河). It connects Beijing And Hangzhou. Its length is 1774 km, and it is the longest canal in the world. It originates in Tongxiang County near Beijing, passes through the cities of Beijing and Tianjin, four provinces - Hebei, Shandong, Jiangsu and Zhejiang and ends in the city of Hangzhou (Zhejiang Province). It also connects five rivers: Haihe, Yellow River, Huaihe, Yangtze and Qiantang.

Approximately 1,200 years later, the canal was extended southward for a distance of about 400 km - to the city of Hangzhou in Zhejiang province. The excavation of this section, completed around 610 AD, required clearing and connecting some of the short canals that already existed there and, in addition, creating a fairway for the large Taihu Lake.

North of Qinjiang, most of the canal was completed under Kublai (the first emperor of the Mongol Yuan dynasty), whose generals conquered Hangzhou. Kublai tried to establish communication routes between his southern possessions and the capital - Khanbalik (as the Mongols called then Beijing). The extension of the canal to the north probably began in 1279 and led it through the lakes. On this route it was necessary to erect dams and build locks, since it was necessary to regulate the water level, since it turned out to be different in different lakes. The northern part of the Grand Canal was called Tsa Ho - the river of locks. The canal entered Shandong province, where it was brought to Dongping; in the area between this city and Jining, navigation is often difficult due to insufficient water flow into the canal bed. Around 1300 AD The canal route was extended to the city of Linjing, on the Weihe River, in northern Shandong.

Photo 3.

At the end of the Yuan Dynasty, the Grand Canal was extended even further north, to Hebei Province, where its waters mixed with the waters of the Beiyunhe River near the city of Tianjin. The section of the canal between the Weihe and Beiyunhe rivers is navigable all year round. Then the canal followed the bed of the Beiyunhe River against its current and reached the settlement of Tongxian, which is 24 km east of Beijing. During the Ming Empire (1368–1644), the canal was significantly improved, and those sections of it that had fallen into disrepair were made navigable again.

With the development of railways (at the end of the 19th and beginning of the 20th century), the Grand Canal lost its former importance. On the lands through which its route ran, devastating floods occurred more than once, and in the mid-19th century. The Yellow River changed its course and began to flow not into the Yellow Sea, but into Bohaiwan Bay in northern Shandong. The severe flood of the Huaihe River in 1931 and the devastating military operations in the period from 1937 to 1949 brought the Grand Canal to a state of complete destruction. By 1949, when the communists won, only junks could navigate it.

Photo 4.

In 1952, the implementation of a program for regulating the water regime in the Huaihe River basin began, which included work to clear, expand and straighten the bed of the Grand Canal. Modern mechanized shipping locks were built on it. The section of the route running through Jiangsu province was reconstructed, and 1000-ton ships began to sail along it. The modernization of the canal was carried out at an accelerated pace, since by this time the railways could barely cope with the transportation of minerals.

Photo 5.

The Grand Canal will play a much more important role as a means of supplying the north of the country with water for agricultural and industrial purposes. Chinese experts suggest that by 2030, when the country's population reaches 1.6 billion people, water resources per capita will amount to 1,760 cubic meters. And according to international standards, the minimum permissible level is 1,700 cubic meters. According to Li Rui, director of the Institute of Land Resources Conservation of the Chinese Academy of Sciences, water consumption in China will reach its peak by 2030, and if effective measures are not taken, the country will face a serious crisis in the future.

According to Chinese scientists, in order to feed its population, which, despite birth control, continues to increase by eight million people annually, China, as in ancient times, still needs to irrigate the arid north of the country. After all, 80 percent of water resources are in the Yangtze basin and areas south of this river. Let me remind you that in central China there are two great rivers that flow from west to east - the Yellow River and the Yangtze. They are almost equal in length. However, the annual flow of the Yangtze is twenty times greater than the Yellow River. Over the years of the existence of the PRC, farmers, mainly in the northern part of the country, managed to increase the irrigated area approximately fourfold - from 15 to 52 million hectares. However, all possibilities have now been exhausted. So much water is taken from the Yellow River for irrigation that in the summer it almost dries up. A different situation exists in the Yangtze basin region. In China it is called the mother river. The Yangtze Basin is one of the main economic regions. Occupying only a fifth of the country's territory, it contributes more than two-fifths of the gross domestic product. And the energy potential of the Yangtze basin is almost three times greater than that of all US rivers combined.

Photo 6.

The idea of turning rivers from south to north was born back in 1952 and belongs to the former Chinese leader Mao Zedong. It is clear that in the conditions of the 50s, when the anti-Japanese war and then the civil war had recently ended, it was completely impossible to implement this project. But they never forgot about him. And in recent decades they have returned to it again. First, all the necessary scientific and practical research was carried out, assessments were made of the difficulties and problems that would have to be solved, and the issue of the need to resettle hundreds of thousands of people from their places of residence where the construction of water structures would take place was resolved. In 2002, the Chinese government decided to launch a project designed to provide water to the arid areas of the country. Now, for nine years now, China has been intensively constructing hydraulic structures for water transfer. This construction has been declared an object of strategic importance in the rational distribution of the country's water resources, in changing the tense situation with water resources in the northern regions of China, which is directly related to social and cultural development and the problem of improving the environment in these areas. This facility, like the construction of the Sanxia hydroelectric complex on the Yangtze River, the laying of a gas pipeline from the western part of the country to the eastern and the construction of the Qinghai-Tibet railway, are called the four most important construction projects of modern China. It is expected that in a few decades a network of canals will appear in China through which water from the Yangtze, Huaihe, Yellow and Haihe rivers will be transported to the northern regions of the country.

To transfer water from the Yangtze River, 3 main canals are built - eastern, central and western. In particular, 6 provinces and centrally subordinate cities, such as Beijing, Tianjin, Hebei, Shandong, Henan and Jiangsu provinces, will receive water through the eastern and western canals. The construction of the eastern canal will use the existing infrastructure of the Great Chinese Canal.

The Grand Canal is not only a transport and water artery. But it is also a magnificent historical monument, connecting the past and present of China.

Photo 7.

Several years ago, representatives of travel agencies from 15 large and medium-sized cities along the Grand Canal gathered in Huai'an City in Jiangsu Province and jointly decided to create a "Grand Canal Tour" tourist route. They stated that they would jointly create and improve a mechanism for interregional cooperation in the field of tourism. And on the Great Chinese Canal, which stretches for almost 2000 kilometers, there are many places worthy of tourist attention. For example, historical production areas. Many ancient objects, for example, shipyards and other industrial enterprises, were moved to other areas of the cities. Industrial buildings and equipment with an interesting history are already being used in a new capacity. For example, tourists live in them or they are the object of display. Such a project was developed for former industrial areas along the Grand Canal in Suzhou.

The Great Canal of China has many bridges and piers. Bridges in historical cities performed not only a purely transport function, but also an important compositional and spatial role. When constructing bridges on the Grand Canal, much attention was paid to their shape. Bridges are very expressive, in which the shape of the arches and their reflection in the water form regular circles.

Photo 8.

The bridges offer picturesque views, so many of them were designed as viewing platforms with canopies for shade and benches. At the same time, the architectural solutions of the bridges were distinguished by individuality and artistic expressiveness.

Abstract on the topic:

Channel (hydrography)

Plan:

1 Types of channels
2 History
- 2.1 Canals in antiquity
- 2.2 Canals in the Middle Ages
- 2.3 Industrial revolution
- 2.4 19th century
- 2.5 XX century
  - 2.5.1 Channels in the USSR
3 Channel arrangement
4 Channel lists

Introduction

Royal Canal in Ireland

Profile of the White Sea-Baltic Canal

Water channel(lat. canalis - pipe, gutter ) - an artificial waterway designed to shorten water routes or to redirect the flow of water. There are two main purposes of the channel:

irrigation, a canal used to deliver or drain water
channels that carry out transport functions, for example for the delivery of goods or people

Often channels combine both functions.

The purpose of creating a shipping canal is to connect the basins of two reservoirs in the absence of one, shorten the path between two reservoirs, ensure guaranteed navigation, solve the problem of transport accessibility along the waterways of destinations, and create economically viable transportation routes.

1. Types of channels

Depending on their purpose, channels are divided into several types.

Since ancient times, reclamation canals have played an important role in agriculture, which, in turn, are divided into irrigation (irrigation) and drainage (drainage) canals. The first of them deliver water to the fields and distribute it there, so they can most often be found in the deserts and semi-deserts of Asia and Africa, as well as in areas where intensive farming is carried out - for example, in California and the Mediterranean. The latter, on the contrary, drain water from the wetland.

Another type of channel is energy. They supply water from rivers to the turbines of a hydroelectric power station, and then remove the water that passes through the turbines outside the hydroelectric power station.

Shipping canals - freshwater and sea - which connect rivers, lakes and seas, are usually designed for all kinds of water transport - from small boats to huge bulk carriers. Shipping canals are divided into open and locked. The first of them connect waterways with the same water level, the second - reservoirs with different levels. Among the open canals, we can name the large Suez and Corinth Canals, but the vast majority of such structures are of the second type: their lock systems allow ships to rise from low sections of the canal to higher ones, and vice versa. The most famous lock canals are the Panama and Kiel canals. In turn, freshwater canals are divided into transit (connect several reservoirs), watershed (connect the basins of two rivers), bypass (bypass) or straightening (go around rapids or stormy areas, and also shorten the path between two points of a winding channel) and connecting (their laid from waterways to large industrial centers).

2. History

2.1. Canals in antiquity

The first irrigation canals appeared at the end of the 6th millennium BC. e. in Mesopotamia. Around the same time, apparently, they began to build irrigation systems in Ancient Egypt, so that by the turn of the 1st and 2nd millennia, a wide network of irrigation canals was created in both countries, the care of which fell on the shoulders of the supreme power. It is possible that the world's first shipping canal appeared in Ancient Egypt, which connected the Red Sea with one of the tributaries of the Nile, a river that flowed into the Mediterranean Sea; thanks to this route, ships could travel from one sea to another. The construction of this waterway began around 600 BC. e. and lasted until 518 BC. e., when the country was captured by the Persians. Unfortunately, over time, the canal was buried under the desert sands and forgotten about.

2.2. Canals in the Middle Ages

2.3. Industrial revolution

2.4. 19th century

The Augustow Canal, connecting the Vistula and Neman basins, is a unique monument of engineering art of the first half of the 19th century. Located on the territory of Poland (80 km) and Belarus (22 km), this hydraulic structure is a striking example of a closed canal, along which 18 locks were built. Construction of the canal began in 1824 and lasted 15 years, and the chief designer was engineer Ignacy Prondzhinsky. Preserved to this day almost in its original form, today this waterway serves mainly tourists: its bed passes through the picturesque landscapes of the Augustow Forest and the Biebrza Lowland, connecting lakes Niecka, Beloe and the Czarna Gancza River. Today, the Augustow Canal is one of the attractions that may be included in the UNESCO World List of Cultural and Natural Heritage.