There are tens of thousands of rivers and streams on our planet. And each of them, even the smallest one, has a territory from which it collects its waters. In this article we will understand what a river basin is and what a watershed is. In addition, you will learn about the largest river basins on Earth.

rivers?

Water, as we know, is in constant motion. Falling onto the surface of the earth in the form atmospheric precipitation, it flows from higher elevations to lower ones. Sooner or later, all this water ends up in some watercourse.

Small streams merge to form small rivers. Those, in turn, flow into larger channels. If you look carefully physical card any territory, you can notice that all the rivers form a peculiar pattern on the surface of the Earth. In its external outline, it resembles a network of human blood vessels or a series of branched trees. Each of these “trees” is a separate river system. Now let’s try to figure out what a river basin is.

In the picture below you can see a picture of a classic river system. This is a diagram of the river basin. Here the Roman numeral I shows the main river, and the numbers II indicate its tributaries. The area outlined in red will be the river basin for this water system.

So what is a river basin? This is the territory from which one or another system collects its waters. A river basin can also be called a drainage basin, or even more simply, a drainage basin. All these terms refer to the same geographical concept.

What types of river basins are there?

All river basins are divided into two types:

• wastewater (the main rivers of which carry their waters into the oceans or seas);
• drainless (the main rivers of which flow into reservoirs that are in no way connected with the World Ocean).

River basins are also divided into:

• superficial;
• underground.

The surface parts of the river basin collect water and moisture that accumulates on the surface of the earth, and the underground parts, respectively, from sources located underground. It is important to note that the size and boundaries of underground watersheds are very difficult to determine. That is why hydrologists most often take into account only surface watersheds when assessing and characterizing a particular river system.

The shape, outline and size of a particular river basin depend on many factors: the geographical location of the river system, topography, vegetation cover, geology of the area, etc.

The largest river basins on the planet

The largest area on Earth is the Amazon River basin, which occupies almost a third of the South American continent. It is also the largest in terms of catchment volume. It is followed by the Congo (in Africa) and Mississippi (in North America). The largest drainage drainage basin on the planet is the Volga River basin.

The table below lists the ten largest river basins on the planet, indicating their area and geographical location.

What is a watershed?

If we return to the diagram presented at the beginning of our article, we can see the red dotted line. This is the watershed - the boundary between river basins.

To more clearly imagine what it is, just take a small oblong stone (preferably with a pointed top) and pour a thin stream of water on it. You will see that one part of the poured water will flow to the ground on one side of the stone, and the other on the opposite side.

In scientific terms, a watershed is a conventional line on earth's surface, which separates two (or more) neighboring catchments and directs the flow of precipitation in opposite directions. By analogy with river basins, watersheds are also divided into surface and underground.

Features and examples of watersheds

It is quite obvious that watershed lines in any area should pass along its most elevated sections. Thus, in mountainous areas they, as a rule, pass along the crests of ridges and individual peaks. On the plains, watersheds are poorly expressed in relief. Here they very often represent rather large flat spaces, within which the direction of water flow can periodically change.

Another important natural law: the higher the watershed line is located, the higher and faster will be the speed of water flow in all rivers and streams that flow from it.

The main watershed of the continent, separating the drainage basins of different oceans, is usually called continental. In Russia, the largest watershed is This is where the largest European rivers originate: the Volga, the Dnieper. Another important watershed in Russia is the Ural mountain system. The rivers that flow from its western slopes carry their waters into the Arctic Ocean. Watercourses flowing from the eastern slopes of the Urals later turn into the most important tributaries of the Ob, the largest river system in Siberia.

The seventh wonder of the world is the Amazon River and its younger beautiful sisters.

Niger is the most valuable river in West Africa, the length of which is 4,180 kilometers. The source of the river is on the slope of the Leon-Liberian Upland. The Niger flows into the Gulf of the Atlantic Ocean. Thus, a delta domain is formed.

Irtysh is located in the Xinjiang Uyghur region of China. (What did you think?))) The length of the reservoir reaches 4248 kilometers. The Ob, together with the Irtysh River, creates the longest watercourse in Russia. It ranks second in the overall ranking in terms of length in Asia. The area of ​​the basin is 1,643 thousand square kilometers. The river is rich in freshwater fish.

Length Lena is 4400 kilometers. and the area is 2490 thousand square kilometers. Thus, the Lena is the longest river in Central Siberia. Large territory The reservoir passes through the Irkutsk region. It is worth noting that in terms of total area Lena is considered the largest in Russia. Moreover, according to location in the regions permafrost There are no analogues to Lena in the world. Lovers of winter fishing come here from all over the world.

Mekong The reservoir is widely known as the “River of Nine Dragons”. Flows through the territory of China, Laos, Thailand, Cambodia, Vietnam, Myanyie On the Indochina Peninsula, the Mekong is the most big river, the length of which is 4500 kilometers

River Congo, located in Central Africa, is also the deepest, with a length of 4,700 kilometers. This unique river, which crosses the equator twice.

Parana. It's about about a long river located in South America. Its length is 4880 kilometers. It flows through several countries, including Argentina, Brazil and Paraguay. The area of ​​the Parana River is 2,582,672 square kilometers.

Interesting Facts.

• The Paraná flows into La Plata Bay;
• in the lower reaches of one of the longest rivers on the planet, shipping is well developed;
• in the middle reaches of the Paraná there is a border between Argentina and Paraguay;
• The name translates as “big river” from the language of the ancient Guarani Indians.

Yellow River. Finding a fresh body of water larger than the Yellow River is quite difficult. One of the largest rivers in China and Asia in general means “yellow”, which is due to the presence large quantity sediment They give it a traditional and extraordinary yellowish tint. Not many people know that it was because of this river, which flows into the Yellow Sea, that the second body of water received its name. The source of the Yellow River is located in the eastern part of Tibet, at an altitude of approximately 4 thousand meters. The total area is 745 thousand km².

In translation Yangtzemeans "long river". A truly large river located in China has a long length (6300 km), covering the territory of many Eurasian countries. One of the largest rivers on the planet is considered the third deepest on Earth. Its area is 1,808,500 square kilometers.

Interesting.

• The Yangtze covers many ecosystems, and is home to unique endemic and rare, endangered species of marine animals. In particular, river dolphins.

The ex-leader in the top of the longest rivers today is Nile, whose length is 6853 kilometers. The source of the freshwater reservoir originates in the East African Plateau. Most of the Nile flows in the desert

And finally - the longest river in the world - the Amazon, the length of which is 6992 kilometers. The area covers 7180 thousand square kilometers. In 2011, a worldwide competition was held, within which the river received the status of one of the seven wonders of the world. For the most part, it flows in the Amazonian lowland, namely in the sublatitudinal zone. Forms a huge delta and flows into Atlantic Ocean. The area of ​​the largest river island is 100 kilometers.

A drainage basin, or watershed, is a part of the earth’s surface, including the thickness of soil from which a river or river network receives water supply. The drainage area genetically determines the quantity and quality of runoff, thereby laying down the basic parameters of natural water resources.

Each river basin has surface and underground watersheds. A surface catchment is an area of ​​the earth's surface from which water flows into a river network. An underground watershed is a part of the soil thickness from which water flows underground into the river network. The surface watershed may not coincide with the underground one.

A river that flows directly into the sea or into a closed lake is called the main one; the rivers flowing into the main one are tributaries of the first order, followed by tributaries of the second order, third, etc. Totality main river with all its tributaries it forms a river system. The ratio of the total length of all rivers of a basin (or other territory) to the area characterizes the density of the river network.

Eight of the world's 50 largest river basins are located in whole or in part on Russian territory: the Ob, Yenisei, Lena, Amur, Volga, Dnieper, Don, and Ural river basins.
The Ob River has the largest basin area - 2990 thousand km2; the length of the river is 3650 km (from the source of the Katun River - 4338 km, from the source of the Irtysh River - 5410 km).

In the Yenisei River basin (basin area 2,580 thousand km2, river length - 3,487 km; length from the sources of the Small Yenisei River - 4,102 km) there is a unique one, which, together with adjacent territories, including protected areas, is classified as a World Natural Heritage Site.
The area of ​​the Lena River basin is 2490 thousand km2. The river, 4400 km long, originates on the slopes of the Baikal ridge, flows into, forming a large (about 30 thousand km2) delta.

Most of the Amur River basin is located in Russia. The Amur is one of the largest rivers in the Far Eastern region (length 2824 km; from the source of the Argun River - 4440 km; basin area 1855 km2). A serious problem of the river is the intensive development of the right bank of the river by the PRC, and therefore last decade The load on the basin's ecosystems has increased sharply. Wasteful use natural resources, with a significant difference between Chinese environmental standards and Russian standards, leads to a change in natural resource potential, in particular, to a deterioration in the condition of valuable species commercial fish, disruption of seasonal migration routes of ungulates and protected species of waterfowl, changes in the river fairway as a result of uncontrolled excavation work in the water protection zone, and its pollution with harmful substances.
The area of ​​the Volga River drainage basin - the largest in Europe - is 1360 thousand km2, that is, 62.2% of the European part of Russia, 8% of the area of ​​Russia, almost 13% of the territory of Europe. 2,600 rivers flow directly into the Volga (length 3,530 km), and in total there are more than 150 thousand watercourses more than 10 km long in the basin. Its largest tributaries are the Oka and Kama rivers. The catchment area of ​​small rivers makes up 45% of the total area of ​​the basin.

The shortest rivers

The shortest in the world are two American rivers: Roe River near the town of Great Falls, pcs. Montana, and Dee River in Lincoln City, PC. Oregon. The Roe River flows into the Missouri River; one of its branches is only 17.7 m long. The Dee River connects Devils Lake with the Pacific Ocean, and its total length is 37 + 1.5 m.

Roe River.

Longest rivers

The two longest rivers in the world are the Nile in Africa and the Amazon in South America.

River Nile, view from space.

The Amazon originates in Peru, where several streams merge to form the Apurimac River, which in turn becomes the Eni, Tambo and Ucayali Rivers. In the last section, 3,700 km long - from the confluence of the Ucayali and Marañon all the way to the mouth - the river is called the Amazon. The Amazon has several mouths, so it is not entirely clear where it ends. If you measure the river moving towards its outermost mouth, the length of the Amazon will be about 6,750 km.

Amazon River, view from space.

The Nile, stretching from Burundi to Mediterranean Sea, had a length of 6670 km until Lake Nasser, formed after the construction of the Aswan High Dam, absorbed several meanders, i.e. bends of the river bed, reducing its length by several kilometers.

Underwater river

In 1952, an underwater river was discovered, called the Cromwell Current. It carries its waters east along the equator under the surface Pacific Ocean at a depth in places reaching 400 m. The unusual river has a width of 300 km and a length of 6500 km.

underground river

In August 1958, using radioisotopes, a river flowing under the Nile was discovered. Its average annual water flow is 6 times greater than that of the Nile - 500 km 2.

Amazon River, view from space.

Most large swimming pool by the river

The largest basin in the world is near the Amazon River - it occupies 7,045,000 km 2.

The longest tributary of the river

One of the tributaries of the Amazon is Madeira (3380 km). Only 17 rivers in the world exceed it in length.

River Ob

The longest estuary by the river

The longest estuary is near the Ob River in northern Russia - its length is 885 km and its width is up to 80 km. The Ob is also the widest river, which, when frozen, is completely covered with ice.

Brahmaputra River

Largest river delta

The most extensive delta in the world is the Ganges and Brahmaputra rivers in Bangladesh and West Bengal, India. It covers an area of ​​75,000 km2.

Largest river flow

Every second, the Amazon discharges 200,000 m3 of water into the Atlantic Ocean, and during flood periods more than 340,000 m3

The most powerful boron inriver

Of all the 60 places in the world where this phenomenon is observed, the most amazing boron (a sharp rise in the water level of a river during high tide) can be observed on the Hanchufe River in Eastern China. During spring tides, the wave moves up the river at a speed of 24 - 27 km/h, and its approach can be heard from a distance of 22 km.

Congo - reka record holder

The Congo is the only major river that crosses the equator twice. It is the deepest and second longest river in Africa, the second largest river in the world after the Amazon.

The Congo is the deepest river in the world; in some sections its depth is more than 230 meters, which is an absolute record on the planet. Mostly such places are located in areas of large waterfalls, such as Livingston Falls (when the water falls from a height of 270 meters).

Longest island river

The Kapuas River flows on the island of Borneo and is the longest river in Indonesia, with a length of 1143 km.

The dirtiest river

The Citarum River is located in Indonesia. The river is an economically important waterway for the area and is heavily polluted by human activity. About 5 million people live in the river basin.

The highest mountain river

The Brahmaputra River originates from the Tibetan Plateau (PRC) at an altitude of more than 3500 m. The river has several names, depending on the area where it flows: in Tibet - Matsang and Yarlung-Tsangpo, at the place where it breaks through the Himalayas - Siang and Dihang, in India - Brahmaputra, in Bangladesh - Jamuna.

The widest river in the world

La Plata is an estuary formed by the confluence of the Uruguay and Paraná rivers in South America. At the confluence of the rivers, the width of La Plata is 48 km, the river flows to the southeast, expanding to 220 km when it flows into the Atlantic Ocean.