The watershed is a concept that is actively studied by the science of hydrology. What is the essence and significance of this concept for science? What types of watersheds are distinguished by scientists? The answers to these questions are in our article.

The watershed is ... Definition of the concept

There are tens of thousands of rivers on our planet. And each of them collects water from a certain area. A watershed is a conditional line drawn on the earth's surface. Before defining the essence of this concept, you should familiarize yourself with some other terms. We are talking about two hydrological concepts: a river system and a river basin.

A river system is a water system consisting of a main river and all of its tributaries. A river basin refers to the area from which all water (both surface and underground) flows into a particular river system. Now we can give a logical and understandable definition of the concept of a river watershed.

A watershed is a line demarcating adjacent river basins. In mountainous or hilly regions, it is more pronounced, and in flat areas it is weaker. In the mountains, watershed lines often follow ridges and ridges. At the same time, the runoff of water and atmospheric precipitation is directed in different directions from the ridge (on opposite slopes).

Within the lowlands, the watershed may not be clearly expressed in relief. Moreover, in such areas, its line may even shift in one direction or another with time or depending on the season.

Main types of watersheds

The watershed separating basins of different oceans or denoting areas of inland runoff is called continental. For example, in America, this line runs along the highest ridges and peaks of the Cordillera and the Andes mountains.

In Europe, the Alps are the most important watersheds, and within the last form of relief, three largest rivers originate: the Volga, the Dnieper, and each of them carries its waters to different seas - to the Caspian, Black and Baltic, respectively.

In addition, it is customary to distinguish between underground and surface watersheds. The first of them delimits underground drainage basins, and the second - surface ones. And they don't always match.

Sometimes the concept of a watershed is used to distinguish between individual major landforms of the Earth. For example, Orinoco is a river that is a watershed between and the Andes in South America. However, such a formulation is not entirely correct from the point of view of hydrological science.

Study of watersheds

The study of the conditional topographic lines described above is of great scientific and practical importance. Especially when it comes to the active development of geographic space by man.

So, when designing bridges, dams or power plants on a river, it is simply necessary to have an idea of ​​​​how the watershed lines run in a particular region. Even more important is the detailed study of watersheds when planning large reservoirs. This is necessary in order to accurately calculate the volume of possible filling of the future reservoir.

The Volga river basin and its watershed

The Volga is the largest river system in Europe, which includes over 150 thousand watercourses: rivers, permanent and intermittent streams. The drainage basin of this river occupies a huge area - 1.36 million square meters. km. This territory is comparable in size to states such as Peru or Mongolia. Within the Volga river basin there are 30 subjects of the Russian Federation, one region of Kazakhstan and dozens of large cities (in particular, Moscow, Ryazan, Tver, Orel, Kazan, Astrakhan, Perm and others).

The Volga watershed runs along the Central Russian Upland in the west, hills in the north, along the western slopes of the Ural Mountains, uplands and the Caspian lowland in the south.

"Where the rivers flow" - Rivers. Pick a pair: concept-definition. The longest rivers in the world. Thresholds-outcrops of hard-to-erode rocks in the riverbed. A waterfall is a fall of water from a high ledge. Figure 2. Figure 1. Goals and objectives: Basic terms and concepts: How to describe the geographical position of the river:

"Geography of the river" - The mouth of the river. Change the letter "e" to "y" - I will become a satellite of the Earth. Rivers. Guess the river: I am the Siberian river, Wide and deep. Interesting geography. Determine on the map. Label the names of the rivers on the contour map. Collecting water from tributaries, the river becomes wider and fuller. Determine on the map into which seas the Ob and Yenisei rivers flow?

"Rivers" - Answers: Source - the Kagera River, Lake Victoria; The mouth is the Mediterranean Sea. Ground. Which tributary of the Nile is right or left? River. The tributaries can be right and left. River system. Pressure. What parts of the river valley do you remember? What parts of the river can you list? The source can be: Spring (groundwater) Glacier Swamp Lake.

"Rhine River" - "Father Rhine". Maiden Island. The most romantic of all German rivers. Rhine. Rhine Mecca for tourists. Rock Lorelei. The Rhine originates in the Swiss Alps. Cologne Cathedral. Evening Rhine is very picturesque. In the lower reaches of the Rhine.

"Yangtze River" - High water and floods happen in summer. Providing water to cities. YANGZI (Blue River, Chinese Changjiang - Long River), in China. "Blue River". It originates in the central part of the Tibetan Plateau. In the lower reaches of the Yangtze is connected to the Grand Canal. River nutrition. There were major floods in 1870, 1896, 1931, 1949, 1954.

"Geography grade 6 of the river" - Parts of the river. Yangtze (Asia) 5800 km. America) 4740 km. 8. Mekong (Asia) 4500 km. 9. Amur with Argun (Asia) 4440 km. 10. America) 6420 km. America) 6400 km. “Oh, the Volga! .. Amazon with Maranyon (South. The largest rivers of the world. Rivers in the works of poets. Volga (Europe) 3531 km. Ob with Irtysh (Asia) 5451 km 6. Huang He (Asia) 4845 km 7. Missouri (Northern .

Water, combined with sunlight and air, is the basis of life on our planet. Pouring onto the surface of the land with fertile rains, it moistens the soil, and its excess is collected in streams and rivers to return back to the ocean, having traveled thousands of kilometers along their winding channels.


The direction of the flow of each of the rivers is determined by the folds of the terrain and the features of the relief. The boundary between the basins of two neighboring rivers is the watershed.

What is a watershed?

From the point of view of geography, a watershed is a conditional line that delimits the basins of two rivers, seas or oceans. On both sides of this line, the flow occurs in different directions, along opposite slopes, and feeds different reservoirs.

There is a watershed area around the watershed line. On the plains, it is located on hilly or elevated areas, but it can also pass through the lowlands, and in mountainous areas it passes along the ridges of the mountains. The flat watershed often does not have a clear line, and the direction of flow is not constant.


When determining the watershed line, it is customary to take into account only external water sources - rivers and streams flowing on the surface. Despite the fact that a significant part of rivers are fed by sources of underground origin, they are not taken into account when drawing watershed lines, since it is often difficult to determine the direction of their flow.

The main watershed of the planet

Between the basins of the Pacific and Atlantic slopes there is a line of the main watershed of the Earth. It runs from Cape Horn along the Andes, Cordillera and Rocky Mountains, reaching the Bering Strait, crosses Asia in a latitudinal direction along the peaks of the Chukotka Range, the Anadyr Plateau, the Gydan and Dzhugdzhur Ranges, then along the Stanovoy and Yablonovy Ranges, passing into the territory of Central Asia, and Africa - along its eastern outskirts to the south almost along the meridian. The Pacific runoff covers about 40% of water resources, the Atlantic one - about 60%.


On each of the continents, a line can be drawn that separates the basins of different oceans or limits the contour of endorheic regions. This line is called the continental divide. The boundaries of the internal flow that does not go to any of the oceans are commonly called the internal watershed. In Eurasia, this is the watershed line of the Caspian basin.

Why study watersheds?

The study of the distribution of water resources, the boundaries of the watershed and the principles of the formation of river flows may seem like a purely academic interest, devoid of practical meaning, but this is not so.

In the process of developing and cultivating the surrounding space, people often have to build various structures on rivers - bridges, dams, hydroelectric power stations, etc. The collected knowledge is necessary for the calculation of the project.

In order to correctly determine the possible amount of runoff, it is necessary to first study the features of the formation of the river flow, the rate of rise in the water level during floods or snowmelt, the presence of underground sources and a number of other factors. All this makes it possible to design a structure with the necessary margin of safety in order to exclude emergency situations during periods of maximum water inflow into the river.


So, when designing a reservoir, it is necessary to calculate the maximum volume of its filling during periods of floods and floods. When building bridges or culverts, the magnitude of the highest water flow should be taken into account.

The operation of the pumping station directly depends on the water level in the river. Seasonal and climatic fluctuations in the flow of rivers have a huge impact on the design of hydraulic structures, so knowing the boundaries of the watershed will help to correctly calculate how much water can arrive in the river at maximum and minimum filling.

Preview:

Examination on the topic "Internal waters of Russia" Option 1

Task 1. Solve the test

1. Indicate the rivers that belong to the Arctic Ocean basin:
a) Ural, Onega, Kama b) Onega, Yenisei, Lena
c) Pechora, Anadyr, Amur d) Kuban, Terek, Dnieper
2. Most of the rivers in Russia have a type of food:
a) rain b) snow c) mixed d) underground
3. Border river:
a) Lena b) Volga c) Yenisei d) Amur
4. Complete the offer:
A relief form that looks like steps or ledges with a horizontal or slightly inclined surface is
a) a watershed b) meander; c) terrace; d) delta.
5. The main river with all its tributaries:
a) river system b) river basin c) river regime
6. Lakes into which rivers flow, but do not originate, are called:
a) drainless b) draining
c) tectonic d) fresh.
7. Flooding most often occurs on rivers flowing:
a) from north to south b) from south to north c) from west to east; d) from east to west.
8. The continuous distribution of permafrost is typical for:
a) Sakhalin Island; b) the Kamchatka Peninsula; c) the Taimyr Peninsula; d) the Kuril Islands.
9. Indicate the territory where rivers with flood regime are located:
a) East European Plain; b) west of the Caucasus Mountains;
c) the Central Siberian Plateau; d) Far East.
10. A flat river is:
a) Terek b) Ob c) Anadyr d) Pechora.

Task 2. Finish the sentence:

A. A constant stream of water flowing in a depression called a channel ____________

B. Changes in the state and level of water in the river during the year ___________

AT. The territory from which the river collects its waters _____________

G. The period in the life of a river when it overflows and floods the floodplain __________

E. The border separating two neighboring river basins _________________

Task 4. Make a diagram "The importance of lakes in nature and for humans"

Task5.

Task 6. Give an answer (yes or no)

1. A set of information about water resources is called a water cadastre.

2. The largest rivers of the Atlantic Ocean basin are the Amur and Lena.

3. Most of the country's rivers are fed mainly by snow and summer floods.

4. About 10% of the country's territory is occupied by swamps, about 60% - by permafrost.

5. The largest glaciers in our country are located on the islands of the Arctic Ocean and the peaks of the Caucasus.

Task 7. Give examples of the largest lakes in the country.

L____something, O__________ something, Ch_________th, P_________ something, I______n, T_______r, T_________ something, B__________l, Kh___ka

Task 8. Determine the fall and slope of the Angara River. The height of the Angara source is the level of the water surface in Lake Baikal - 456 m. The height of the mouth - the place where the Angara River flows into the Yenisei - 76 m. The length of the river is 1826 km. Write down the formula and do the calculations.

Task 10. Determine the description of the river:
Belongs to the basin of the Arctic Ocean, originates in the Altai Mountains. The river basin of the river, together with its tributaries, is the largest in Russia.

Control work on the topic "Internal waters of Russia" Option 2

Task 1. Solve the test:

1 . Name the rivers that belong to the Pacific Ocean:
a) Lena, Indigirka, Kama b) Oka, Neva, Terek
c) Kamchatka, Anadyr, Amur d) Kuban, Irtysh, Ishim
2. Depends on the climate:
a) the speed of the current b) the regime of the river c) the direction of the current
3. Border lake of Russia:
a) Baikal b) Onega c) Khanka d) Chany.
4. Complete the sentence.
The plain formed from river sediments in front of the mouth of the river, on which the river divides into branches, is
a) delta b) terrace c) meander d) watershed
5. A short-term rise in the water level in the river, caused by the influx of heavy rainfall into the river:
a) high water b) high water c) flood
6. Rivers predominate in our country:
a) with a summer flood; b) with a flood regime; c) with spring flood;
7. Most of the rivers in Russia have a mixed diet with a predominance of:
a) rain b) snow c) underground d) glacial
8. Mountain glaciers are common to:
a) the Caucasus; b) Southern Urals; c) the Putorana plateau; d) Vasyugan.
9. Which of the regions is characterized by the highest degree of swampiness of the territory?
a) Western Siberia; b) Ural;
c) the Far East; d) North Caucasus.
10. A mountain river is:
a) Volga b) Ural c) Terek d) Lena

Task 2. Finish the sentence:

A. Natural depression on land filled with water ________

B. Change in the state and level of water in the river during the year ___________

C. The flow of water into the river from various sources ______________

D. The period in the life of the river when it is ice-bound ____________________

D. The main river with all its tributaries ________________

Task 3. Find a match:

Task 4. Make a diagram "The importance of swamps in nature and for humans"

Task5.

Task 6. Give an answer (yes or no)

1. For daily needs, a person consumes 300-400 liters of water.

2.2/3 of the country's area is occupied by river basins that carry their waters to the seas of the Atlantic Ocean

3. The largest river in the Pacific Ocean is the Volga.

4. The Amur River is fed mainly by rain and floods in the warm season.

5. The most swampy are the north-west of the Russian Plain (up to 20-30%), Vasyugan in the West Siberian Plain (up to 70%), the Amur basin (10-12%)

Task 7. Name the types of lake basins:

T_______th L_______th B_______th K_______th Zaprudnoe Estuaries Termokarstovoe

Task 8. Determine the fall and slope of the Volga River, which begins on the Valdai Upland. The height of the source is 226 m. The Volga flows into the Caspian Sea, the water surface level in which is -28 m. The length of the river is 3531 km. Write down the formula and do the calculations.

Task 9. What objects are shown on the map under the numbers 1-6?

Task 10. Identify the river according to the description:
It originates in the glaciers of Elbrus, flows into the Sea of ​​Azov, forms a delta. In the warm part of the year, the level in the river remains high due to the melting of snow and ice in the highlands. Often this diet leads to floods.

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 on the surface of the earth in the form of precipitation, it flows from the more elevated parts of the relief to the lower ones. Sooner or later, all this water ends up in a stream.

Small streams, merging, form small streams. Those, in turn, flow into larger channels. If you carefully consider the physical map of any territory, you will notice that all the rivers form a kind of pattern on the surface of the Earth. According to its external outlines, 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 an image 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 - 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 this or that system collects its waters. A river basin can also be called a drainage basin, or even more simply, a catchment area. All these terms refer to the same geographical concept.

What are river basins?

All river basins are divided into two types:

• sewage (the main rivers of which carry their waters to the oceans or seas);
• endorheic (the main rivers of which flow into bodies of water that are in no way connected with the oceans).

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 it is very difficult to determine the size and boundaries of underground watersheds. That is why hydrologists most often take into account only surface watersheds when assessing and characterizing a particular river system.

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

The largest river basins in the world

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

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

What is a watershed?

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

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

In scientific terms, a watershed is a conditional line on the earth's surface that separates two (or more) neighboring watersheds 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 the watershed lines in any locality must pass through its most elevated sections. So, in mountainous regions, they, as a rule, pass along the crests of ridges and individual peaks. On the plains, the watersheds in the relief are weakly expressed. Here they very often represent rather large flat spaces, within which the direction of the water flow can periodically change.

Another important natural pattern: the higher the watershed 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 mainland, separating the drainage basins of different oceans, is commonly called continental. In Russia, the largest watershed is. It is here that 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 to the Arctic Ocean. Watercourses flowing down from the eastern slopes of the Urals later turn into the most important tributaries of the Ob, the largest river system in Siberia.