Australia is the smallest continent in the world and is located in the southern hemisphere. The area of ​​Australia with the islands is less than 8 million square meters. km, the population is about 23 million people.

The western and southern coasts of the mainland are washed by the Indian Ocean, the north by the Timor and Arafura seas of the Indian Ocean, and the east by the Coral and Tasman seas. Pacific Ocean. The extreme points of Australia: in the north - Cape York, in the west - Cape Steep Point, in the south - Cape Southeast, in the east - Cape Byron. The distance from the extreme northern to the extreme southern points of the mainland is 3200 km, from the western to the eastern - 4100 km. Parallel to the eastern coast, the Great Barrier Reef stretches for 2300 km.

The coast of the mainland is slightly indented. There are large gulfs Great Australian in the south and Carpentaria in the north. In the northern part of Australia there are two peninsulas with the largest area, Cape York and Arnhemland. This continent includes adjacent islands - Tasmania, Melville, Kangaroo, etc.

The mainland lies on the ancient Australian platform, which passes into the East Australian fold belt. The average height of Australia is 215 m above sea level, and most of the mainland is occupied by plains and up to 95% of the territory is below 600 m. In the eastern part of the mainland, the Great Dividing Range stretches along the coast, which includes several flat-topped mountain systems. In the western part of the continent there is a plateau up to 500 m high with table mountains and ridges, in the central part there is a lowland with a large lake Eyre. On the territory of the mainland there are deposits of minerals, such as hard and brown coal, copper, iron ore, bauxite, titanium, polymetallic and uranium ores, diamonds, gold, natural gas, oil.

Most of Australia is located in the tropical climate zone. northern regions- in the equatorial zone (with a hot climate and frequent summer rains), the southern ones - in the subtropics (with a predominance of precipitation in winter). In the middle part of the continent, 70% of the territory is dominated by a desert and semi-desert climate. The east coast has a hot tropical maritime climate, where precipitation occurs mainly in summer period. The amount of average annual precipitation decreases from east to west.

Large river systems of the mainland - Murray, Darling, Flinders. A characteristic feature of Australia is the presence of screams - rivers that fill with water only after heavy rains.

On extensive interior spaces mainland are the Great Gibson Desert, Victoria, the Great Sandy Desert, etc. Salt lakes can often be seen here. A belt of semi-deserts with shrubs extends around the deserts. In the northern, eastern and southeastern regions, semi-deserts are replaced by savannahs. In the mountainous regions and along the coasts, forests of palm trees, tree ferns and eucalyptus trees grow. Among wild animals in Australia, rabbits, pigs, wild dogs are found in large numbers. Among endemic animals there are many marsupial forms (kangaroos, wombats, marsupial wolves, marsupial moles).

The entire territory of the mainland and the island of Tasmania is occupied by the country of the Commonwealth of Australia. The state is divided into six states: Victoria, New South Wales, Queensland, Western Australia, South Australia, Tasmania. Indigenous people make up only 2% of total strength population, the rest of the inhabitants are the descendants of Europeans and Asians who colonized the mainland after its discovery in the 17th century. The high level of development of agriculture and the mining industry have brought the country to the leading position as a supplier of wheat, coal, gold, iron ore to the world market.

Measuring the length of rivers is not an easy task, which, however, has been greatly simplified since the advent of artificial satellites. But even with the help of images from space, it is not possible to determine the exact length of the river. Difficulties in determining the beginning of a river may be due to the large number of tributaries. Of all the tributaries, the one that begins at the farthest point from the mouth is considered the beginning of the river, giving the river a total total length, and the name of this tributary is usually not the same as the name of the river. It can also be difficult to determine where the river ends, because the mouth of the river is often an estuary, gradually widening and opening into the ocean.

Estuary (from lat. aestuarium - flooded mouth of the river) - a single-arm, funnel-shaped mouth of the river, expanding towards the sea. One can think of an estuary as a place where the sea is wedged into the mainland/island due to the washing out of rocks.

Seasonal changes also contribute to the complexity of calculating the total length of river systems. This list shows the lengths of river systems, that is, rivers, taking into account their longest tributaries.

10. Congo - Lualaba - Luvua - Luapula - Chambeshi

The Congo is a river in Central Africa that flows into the Atlantic Ocean. The length of the river system of the Congo - Lualaba - Luvua - Luapula - Chambeshi - 4700 km (The length of the Congo River is 4374 km). This is the deepest and second longest river in Africa, the second river in terms of water content in the world after the Amazon.

The width of the river is on average 1.5-2 km, but in some places it reaches 25 km. The depth of the river reaches 230 m - this is the deepest river in the world.

The Congo is the only major river that crosses the equator twice.

9. Amur - Argun - Muddy channel - Kerulen

Amur is a river in the Far East in East Asia. It flows through the territory of Russia and the border between Russia and China, flowing into the Sea of ​​Okhotsk. The length of the river system Amur - Argun - Mutnaya channel - Kerulen is 5052 km. The length of the Amur is 2824 km

8. Lena - Vitim

Lena - a river in Russia, the largest river in Eastern Siberia, flows into the Laptev Sea. The length of the Lena-Vitim river system is 5100 km. The length of the Lena is 4400 km. The river flows through the area Irkutsk region and Yakutia, some of its tributaries belong to the Trans-Baikal, Krasnoyarsk, Khabarovsk Territories, Buryatia and the Amur Region. The Lena is the largest of the Russian rivers, whose basin lies entirely within the country. It freezes in the reverse order of opening - from the lower reaches to the upper reaches.

7. Ob - Irtysh

The Ob is a river in Western Siberia. It is formed in Altai at the confluence of the Biya and Katun. The length of the Ob is 3650 km. At the mouth it forms the Gulf of Ob and flows into the Kara Sea.

The Irtysh is a river in China, Kazakhstan and Russia, the left, main, tributary of the Ob. The length of the Irtysh is 4248 km, which exceeds the length of the Ob itself. The Irtysh, together with the Ob, is the longest watercourse in Russia, the second longest in Asia and the seventh in the world (5410 km).

Irtysh - the longest tributary river in the world

6. Huang He

Huang He is a river in China, one of the largest rivers in Asia. The length of the river is 5464 km. The Yellow River originates in the eastern part of the Tibetan Plateau at an altitude of over 4,000 m, flows through the Orin-Nur and Dzharin-Nur lakes, spurs of the Kunlun and Nanshan mountain ranges. At the intersection of the Ordos and the Loess Plateau, it forms a large bend in its middle course, then through the gorges of the Shanxi Mountains it enters the Great Plain of China, along which it flows for about 700 km until it flows into the Bohai Bay of the Yellow Sea, forming a delta in the area of ​​its confluence.

Translated from Chinese its name is "Yellow River", which is associated with an abundance of sediment, giving a yellowish tint to its waters. It is thanks to them that the sea into which the river flows is called Yellow.

Yellow River - Yellow River

5. Yenisei - Angara - Selenga - Ider

Yenisei - a river in Siberia, one of the greatest rivers in the world and Russia. It flows into the Kara Sea of ​​the Arctic Ocean. Length - 3487 km. The length of the waterway: Ider - Selenga - Lake Baikal - Angara - Yenisei is 5550 km.

Angara - a river in Eastern Siberia, the largest right tributary of the Yenisei, the only river flowing from Lake Baikal. It flows through the territory of the Irkutsk region and the Krasnoyarsk region of Russia. Length - 1779 km.

4. Mississippi - Missouri - Jefferson

The Mississippi is the main river of the largest river system in North America. The source is located in Minnesota. The river mainly flows in a southerly direction and reaches a length of 3770 kilometers, ending in a vast delta in the Gulf of Mexico.

The Missouri is a river in the United States, the largest tributary of the Mississippi. The length of the river is 3767 km. It originates in the Rocky Mountains, flows mainly in east and southeast directions. It flows into the Mississippi near the city of St. Louis.

The length of the Mississippi - Missouri - Jefferson river system is 6275 km.

3. Yangtze

The Yangtze is the longest and most abundant river in Eurasia, the third river in the world in terms of full flow and length. It flows through the territory of China, has a length of about 6300 km, the basin area is 1,808,500 km².

2. Nile

The Nile is a river in Africa, one of the two longest rivers in the world.

The river originates in the East African Plateau and flows into the Mediterranean Sea, forming a delta. In the upper reaches, it receives large tributaries - Bahr el-Ghazal (left) and Achva, Sobat, Blue Nile and Atbara (right). Below the mouth of the right tributary of the Atbara, the Nile flows through the semi-desert, having no tributaries for the last 3120 km.

For a long time, the Nile water system was considered the longest on Earth. In 2013, it was established that the Amazon has the longest river system. Its length is 6992 kilometers, while the length of the Nile system is 6852 kilometers.

Feluca is a small deck vessel with peculiar slanting sails in the form of a trapezoid or a triangle trimmed from one corner.

1. Amazon

The Amazon is a river in South America, the largest in the world in terms of basin size, full flow and length of the river system. It is formed by the confluence of the Maranion and Ucayali rivers. The length from the main source of Maranyon is 6992 km, from the source of Apacheta discovered at the end of the 20th century - about 7000 km, from the source of Ucayali over 7000 km.

However, there are long rivers not only on the ground, but also under it. Hamza is an informal name for the underground current under the Amazon. The opening of the "river" was announced in 2011. The unofficial name is given in honor of the Indian scientist Valiya Hamza, who has been exploring the Amazon for more than 45 years. Hamza flows at a depth of about 4 km underground through porous soils parallel to the Amazon. The length of the "river" is about 6000 km. According to preliminary calculations, the width of Hamza is about 400 km. The flow rate of the Hamza is only a few meters per year - this is even slower than the glaciers move, so it can be called a river rather conditionally. Hamza flows into the Atlantic Ocean at great depths. The water of the Hamza River has high level salinity.

20 longest rivers, excluding the length of tributaries

1. Amazon - 6992 km
2. Nile - 6852 km
3. Yangtze - 6300 km
4. Yellow River hotels - 5464 km
5. Mekong - 4500 km
6. Lena - 4400 km
7. Parana hotels - 4380 km
8. Congo - 4374 km
9. Irtysh hotels - 4248 km
10. Mackenzie hotels - 4241 km
11. Niger - 4180 km
12. Missouri - 3767 km
13. Mississippi - 3734 km
14. Ob - 3650 km
15. Volga - 3530 km
16. Yenisei hotels - 3487 km
17. Madeira - 3230 km
18. Purus - 3200 km
19. Indus - 3180 km
20. Yukon -3100 km

K.S. LAZAREVICH

In No. 5/2006, diagrams of the river systems of Russia were printed. The experience turned out to be successful: the schemes allowed teachers to navigate the difficult (and very confusing textbook authors who do not take the trouble to think about the numbers) question about “the longest rivers” and “the longest watercourses” in Russia or in its individual territories.

It publishes schemes for all continents, built on the same principle as the schemes for Russia. Schemes allow you to set the length of rivers, compare rivers and systems with each other, make a visual representation of river systems and watersheds of the seas.

Within the diagram for each continent, the rivers are placed in the order in which their mouths are located along the coast. oceans circling the area in a clockwise direction. Rivers that do not flow into the World Ocean are given after all, on a gray background.

The rivers - the main ones and their tributaries - are depicted by vertical lines. The flow of rivers is everywhere from the bottom up, so that the left tributaries and components of the rivers are on the left, the right ones are on the right. The lengths of the rivers are given on a scale, they are depicted by vertical lines, the horizontal segments are given only to show the ratio of the rivers, and have no conditional length.

The numbers written on the diagram at the sources of the rivers and at the horizontal segments indicate the distances along the channel from the mouth of the main river; the numbers written along the vertical segments indicate the length of these segments; all values ​​are in kilometers. Along the upper frame of the scheme, reservoirs are marked, where the rivers flow. All signed figures are taken from reference books; It should be borne in mind that for little-studied territories (for example, in Africa, South America), the lengths of many rivers are given with an accuracy of hundreds or even thousands of kilometers. If you want to determine the distances that are not signed on the diagram (for example, between the mouths of tributaries), use the scale bar. But at the same time, remember that such measurements will only give an approximate result: the constructions were made by measuring on the map.

It is better to use the scheme with a map in front of your eyes, then the relative position of the rivers will be clear. In the comments to the diagram, only those places that may cause doubt are explained: unusual forms of mouths and the questions that arise in connection with this about the lengths of rivers; the flow of a river from one drainage basin to another, the temporary drying up of rivers.

Eurasia is the only continent where the drainage basins of all four oceans are located.

River systems are placed in the order of their mouths along the coast of Asia, from the northern end of the Ural Mountains, skirting the continent, to the Sea of ​​Azov. Next comes Europe - first south, then west and north. At the end of the diagram - the rivers of endorheic basins. The Jordan River in Western Asia, although very famous, is not shown, its length is only 250 km, that is, less than a centimeter in the diagram.

IN Asia the rivers of the Arctic Ocean basin flow through the territory of Russia, only some rivers of the Ob and Selenga systems in the Yenisei system begin outside our country.

The longest river in Asia and Eurasia, the Yangtze (other names are Changjiang, Yangtzyjiang), flows in the Pacific Ocean. The Huaihe River, which flows into it in its lower reaches, carries and deposits a lot of solid material (sand, clay), so the channel mainly lies above the adjacent plain, which often caused catastrophic floods, the river flowed either to the Yangtze or to the Yellow River. After the construction of the irrigation system in the 50-60s of the twentieth century. The threat of flooding has been largely eliminated, but part of the flow of the Huaihe continues to flow into the Huanghe, which is reflected in the diagram.

The Mekong River flowing into the South China Sea is one of the longest rivers in Asia, full of water, but the basin area is very small (with a length of 4.5 thousand km, the average width of the basin is 180 km), since the system of parallel ridges of the Sino-Tibet Mountains creates a series of isolated long and narrow watersheds.

The Ganges and Brahmaputra flow into the Bay of Bengal of the Indian Ocean, forming a common delta, the left channel of which is called Meghna, or Meghna. In reference books, the length of the Ganges is 2700 km, the Brahmaputra - 2900 km; apparently, Meghna is included in this length, on the basis of which the scheme is built.

The Tigris and Euphrates rivers in historical times flowed into the Persian Gulf separately, but then merged and formed the Shatt al-Arab river 195 km long.

Of the rivers flowing into the seas of the Atlantic Ocean, we note only the Turkish Kyzylyrmak and our Kuban; the latter is assigned to Asia, as it flows south of the Kuma-Manych depression.

Europe is studied at school in more detail than other parts of the world, many geographical features of Europe are constantly heard, so the scheme also includes small, by the standards of other territories, but well-known rivers. Of the rivers of Europe, only the Volga and Danube can be compared with the largest Asian rivers, although they are significantly smaller.

Europe is essentially a peninsula of the Eurasian continent. Within its boundaries, Western Europe stands out, located outside former USSR, and Eastern Europe - within its limits.

In Eastern Europe, mostly flat, rivers flow from its central part into the Azov, Black, Baltic, White and Barents Seas, as well as into the Caspian Sea, which is not connected to the ocean. From the center of the Russian Plain to the seas - one and a half to two thousand kilometers, and a river two (Dnepr, Don), or even three and a half thousand kilometers long (Volga) is not surprising.

And in the long and narrow Western Europe there is generally no point more than 600 km from the sea, and almost all rivers are short. Only the Danube, starting less than four hundred kilometers from the Mediterranean and five hundred from the North, managed to go half Western Europe along and get almost three thousand kilometers to the Black Sea. Rivers south of the Danube flow into the Mediterranean Sea, north - into the North and Baltic. To the west of the source of the Danube, the watershed runs through southern Europe - these are the Alps, the Central French Massif, the mountains of southern Spain (Cordillera Betica, Sierra Nevada), and the rivers that flow into the Mediterranean Sea are quite short, and the longer ones flow directly into the Atlantic Ocean, into Bay of Biscay and the English Channel. That is why the Mediterranean Sea is somewhat saltier than the Atlantic Ocean. An exception from the rivers flowing into the Mediterranean is the Ebro, which, starting in the Cantabrian mountains, just fifty kilometers from the Bay of Biscay, cuts off the entire Iberian Peninsula, bravely breaks through to the Mediterranean Sea and, after passing 928 km, flows into it.

On the diagram, the French rivers Garonne and Dordogne, which form a common Gironde estuary 75 km long, can cause difficulty. The length of both rivers is counted from the outlet of the Gironde to the Bay of Biscay.

The scheme of the river of endorheic basins is being completed. The Caspian Sea washes the southeastern outskirts of Europe only for a short distance, but the drainage basin of the Caspian occupies 1/7 of Europe, and the Volga is certainly in first place among European rivers in terms of basin area.

The Amu Darya and Syr Darya flow into the Aral Sea. But that is why the Aral Sea dies, because these rivers do not flow into it all year long - their water is taken apart for irrigation; the channels in the lower reaches are shown by a dashed line. The bed of the Tarim (in the upper reaches of the river is called Yarkand) is very unstable, the Tarim only occasionally feeds Lake Lobnor, sometimes it goes into other water bodies or into the ground, so we can only speak about its length approximately.

The river network belongs to the basins of the Atlantic and Indian oceans. The Nile system is located in the eastern part of the continent, very close to the Indian Ocean, but the Nile flows into the Mediterranean Sea - the sea of ​​\u200b\u200bthe Atlantic Ocean.

The Volta River, which flows into the Gulf of Guinea of ​​the Atlantic Ocean, was previously formed from the confluence of the White Volta and the Black Volta; the latter is longer and is considered the main source of the Volta. Now that the Volta reservoir has been created (the largest in the world in terms of area, almost 400 thousand km 2), the White and Black Volta flow into it, and the Volta River begins from the dam of the reservoir.

North America

The rivers of North America belong to the basins of three oceans. The great rivers Mackenzie (in the Beaufort Sea) and Nelson (in the Hudson Bay) flow into the Arctic Ocean. To the south, the relief of the continent predetermines a sharp asymmetry of the river network: the basin of the Atlantic Ocean is much larger than the basin of the Pacific. The largest river system of the continent, the Mississippi system, belongs to the Atlantic Ocean.

The river system that creates runoff from the Great Lakes has no analogues in the world. It does not have a single river longer than 1000 km, but in general the system, consisting of four lakes and five rivers, is only slightly inferior in length to the Volga. (Which of the Great Lakes was not included in this system and why?)

South America

The continent is washed by two oceans, and the length of the coastline of the oceans does not differ much. Nevertheless, all the rivers included in the scheme refer only to the Atlantic Ocean basin - directly to the ocean or caribbean, and there is not a single river of any length that flows into the Pacific Ocean. As in North America, only to a much greater extent, the asymmetry of the relief is manifested, the position of the interoceanic watershed is very close to the western margin of the mainland. The diagram shows a bifurcation - the division of one river into two: in the upper reaches of the Orinoco, the 410 km long Casiquiare River separates from it, flowing into the Rio Negro - a tributary of the Amazon; the broken arrow on the diagram shows where the Casiquiare flows into, but, of course, it is impossible to measure the distance along this arrow. We have already met with a similar division of the river in the Yangtze system, but there the phenomenon is temporary.

Australia

Geography textbooks say that Australia is the driest continent. This is confirmed by the scheme: there is only one large river flowing into the ocean - the Murray. And is it so big if it carries about 10 km 3 of water into the ocean per year? For comparison: the Amazon - almost 7000, the Lena - more than 500, the Volga - 250. And there is also Coopers Creek, which reaches Lake Eyre only during heavy summer rains, otherwise it just goes into the ground somewhere halfway.

Tasks for working with diagrams,
printed on p. 10–18

Give assignments to students little by little; it is up to the teacher to indicate or not to indicate in which river system the solution should be sought; it is quite possible that the same teacher in one class will give additional explanations, but not in another.

1. Determine the distances along the rivers between characteristic points of rivers of the same system; such points can be the sources of different rivers, the mouths of tributaries and the main river, the exit of the river from the lake, etc. For example:

From the source of the Don to the mouth of the Seversky Donets;

From the source of the Tisza to the source of the Danube;

From the mouth of the Saone to the exit of the Rhone from Lake Geneva;

From the source of the Maranyon to the source of the Ucayali (remember which river system they belong to).

There can be many tasks of this type. Invite students to create several of these tasks on their own. Let them familiarize themselves with how the diagrams were drawn up (the introductory part of the explanatory text to the diagrams), and answer which of the tasks you proposed and which of those compiled by them can be solved exactly, which - only approximately and why.

2. When solving each example from task 1 mark which rivers, up or down their course, you move from the starting point to the final point.

3. Using any cards, arrange on the schemes of the rivers of the city.(Let the teacher offer a list of cities himself. Considering that in the next task it is proposed to measure the distances between cities, several cities should be selected in the same river system.) If students do not know where to look for these cities, let them look in the index of geographical names of the atlas . If the city is located on both banks of the river or you do not know which bank it is on, put the circle on the line denoting the river, if on one bank, then on the corresponding side of the line.

Which of these cities did you manage to draw exactly, which approximately? Why?

4. Measure at least 10 distances between by you river cities. Which of these distances did you manage to measure accurately, which approximately? Why?

5. Place a north-south arrow next to each river system. The rivers are winding, so it can only be placed approximately, given the general direction of the main river. For the Mississippi system, place (dashed) the second arrow corresponding to the Missouri source being taken as the main source.

6. Check black triangle in diagram mouths of rivers with deltas. Not all deltas are visible on the map, indicate only those that are expressed to scale on physical maps of the continents and parts of the world in school atlases.

Rivers Eurasia carry almost half of all the waters flowing from the land of the planet into the World Ocean. In terms of river runoff, the continent surpasses all continents. Of the 14 greatest rivers in the world (more than 3 thousand km long), most of them are located in Eurasia: Yangtze, Huang He, Mekong, Indus, Lena, Ob, Yenisei, Volga.

Rivers are unevenly distributed across the mainland. The most powerful river systems are located in Asia - in its northern, eastern and southeastern parts. In the central regions, the river network is almost absent. Europe is dominated by small rivers. The largest rivers of Eurasia originate in the depths of the mainland high in the mountains and spread in all directions to the marginal plains. In the upper reaches they are all mountainous, in the lower reaches they are flat, calm and wide. Flowing out of the mountains, the rivers lose speed, expand the valley and deposit the material brought in it - alluvium. Alluvial are the largest plains of Eurasia.

Rivers of Eurasia are extremely diverse in terms of food types and runoff regime. The same river, crossing different climatic zones, feeds on water from different sources in its different sections, overflows with floods and becomes shallow at different times. Most of the rivers have atmospheric feeding: mixed - snow and rain or predominantly rain. These are the rivers of the outskirts of the mainland with non-continental climates. High water on different rivers occurs at different times of the year, depending on the onset of the rainy season or the snow melting. In the rivers of continental regions, groundwater plays the main role in nutrition. During low water, some dry up completely. Rivers originating in the mountains of Europe, in the center, in the east and southeast of Asia, are fed by the waters of melting glaciers. Asian rivers flowing through permafrost also have a glacial type of nutrition.

River basins. Rivers carry water collected from 65% of the territory of Eurasia to all four oceans of the planet. A third of the continent's surface has no runoff into the oceans. Accordingly, the territory of Eurasia is divided into five drainage basins. Four of them are ocean basins, and the fifth is an internal runoff basin. This is the largest internal runoff basin on the planet.

Pool Arctic Ocean occupies the northern edge of Eurasia. "Record holders" of the basin: Lena - has the longest length - 4400 km; the Ob (3650 km, with the Irtysh 5410 km) - the largest catchment - about 3000 km 2 (Fig. 39); Yenisei (from the confluence of the Big and Small Yenisei - 3487 km) - carries the largest amount of water into the ocean - 630 km 3 / year (Fig. 40). These rivers originate in the mountains. They flow to the ocean along the plains - low or elevated, from south to north - crossing several natural zones. A significant part of their valleys is located in the permafrost zone. They feed on melted snow, rain and glacier waters. In winter they freeze, and many of their medium-sized tributaries freeze to the bottom.

Basin rivers Pacific Ocean - Yangtze (6380 km) (Fig. 41), Huang He (4845 km), Mekong(4500 km) (Fig. 42), Amur(2850 km) - have a monsoon type of regime and are distinguished by high water. In the summer, when the rainy season begins and the snow melts in the mountains, up to 80% of their annual runoff falls. The water level at this time rises by 20-40 m. Floods are accompanied by severe floods. At this time, the rivers flood their valleys and fill them with a thick layer of loose sediments. The longest river on the continent second only to the Nile, the Amazon and the Mississippi, Yangtze. It begins in Tibet, breaks through rapids into the alluvial plain, where it flows among boundless lakes and swamps. At the confluence with the East China Sea, it forms a narrow long estuary - a funnel-shaped extended mouth. It's shaped by power sea ​​tides rising up the river for several hundred kilometers. By the rivers of the basin indian ocean also monsoonal. The largest are Indus (3180 km), Brahmaputra (2900 km) (Fig. 43), Ganges(2700 km), Tigris, Euphrates- originate high in the mountains. Bo Ђ Most of their valleys lie in foothill troughs, and the rivers tirelessly fill them with alluvium. Its thickness in the Ganges valley reaches 12 km. The Ganges-Brahmaputra system in terms of water content is the third after the Amazon and the Congo: 7700 m 3 of water is carried into the ocean every second. Over 500 km from the ocean, the Ganges begins to form branches of a giant delta - the largest in the world. the globe(with an area of ​​​​more than 80 thousand km 2).

From the rivers of other river basins Atlantic Ocean are diverse. They do not form large systems, have a smaller and more uniform flow, all possible power sources. Some of them freeze in winter, while others do not freeze over. Polomaputra (space image)

water and floods occur at different times. The largest river Danube(2850 km) - begins in the Black Forest mountains and flows through the territory of nine countries. Mountainous, rapids in the upper reaches, in the middle and lower it becomes a typical flat river - calm, with a wide floodplain and numerous oxbow lakes. The river cuts through the Carpathians in a narrow valley and, splitting into branches, flows into the Black Sea.

Pool internal runoff occupies the central part of the mainland. Its rivers are usually short and do not form a dense network. They feed mainly on groundwater and often do not bring water to rare lakes, getting lost in the sands of deserts.

Not at all typical for the basin is its main river Volga(3530 km) - largest in Europe. It crosses the East European Plain from north to south. In the upper and middle reaches, the river is very full-flowing - it is fed by abundant waters of melted snow and rain. To the south, they dry up, but the consumption increases - for evaporation and household needs. The Volga flows into the Caspian, forming a powerful delta consisting of hundreds of channels and islands.

lakes Eurasia are numerous and varied. They are unevenly distributed over the territory and differ in the origin of the basins, size, nutrition, temperature regime, and salinity.

The northern part of the continent, covered by an ancient ice cover, is dotted with glacial lakes. The largest (including the largest in Europe Ladoga And Onega lakes) occupy tectonic troughs deepened by the glacier. Many glacial lakes are also in the mountains Central Asia and in the Himalayas. Distributed in southern Europe, western and southeastern Asia karst lakes. Far East and the Japanese islands are rich volcanic lakes. Widespread in river valleys floodplain old lakes. A significant part of the Eurasian lakes have basins tectonic origin. This is the largest lake in the world - the Caspian, and also Aral And Balkhash. Their depressions are the remains of the ancient Tethys Ocean. The largest lakes in central Europe - Constance And Balaton- located in foothills. Areas of continental rifts occupy the deepest lakes - Baikal (1637 m) and Dead Sea. Lake in a tectonic basin Issyk-Kul.

The lakes of areas with a humid climate are fresh, those with a continental climate are salty to varying degrees. The salinity of endorheic lakes is especially high.

The surface of this drainless lake in Arabia is the lowest place on Earth’s land, 405 m below sea level. In some years, the water level drops to -420 m, and salinity, usually 260-270 ‰, increases to 310 ‰. Organic life in the waters of the lake is impossible, hence its name - the Dead Sea (Fig. 45).

The groundwater. Swamps. The underground waters of Eurasia are concentrated in large basins. East and Southeast Asia are especially rich in them. The wide distribution of swamps and wetlands is another feature of Eurasia. Bogs are typical in the tundra and forest-tundra, in the permafrost zone, and are very widespread in areas with a monsoon climate.

permafroston no continent planets(except Antarctica) not as widespread as in Eurasia. In the Asian part of the continent, it extends south to 48°N. w (Fig. 47). Permafrost formed during ancient glaciation. Modern climate in high latitudes it contributes to its preservation (relic permafrost), and in the inland regions of the temperate zone - to its formation (modern). The thickness of frozen rocks reaches its greatest thickness in the upper reaches of the Vilyui River in Yakutia - 1370 m.

Using Figure 47, compare the distribution of permafrost in North America and in Eurasia, in Europe and in Asia. What explains the differences in its distribution?

Glaciation in Eurasia, it is significant in area - 403 thousand km 2, but it accounts for only 0.75% of the mainland. Almost 90% of the glaciers of Eurasia - mountain . In Europe, the most powerful mountain glaciation is in the Alps, in Asia - in the Himalayas (30 times more extensive than the Alpine). Integumentary glaciation is developed on the northern islands.

In the Caucasus, in Scandinavia, in the Polar Urals, Taimyr, northeast Siberia, Kamchatka, the Japanese islands, glaciation is facilitated by the oceanic (or coastal) position of the mountains, which makes it possible to retain precipitation. The formation of glaciers in Central Asia - in the Pamirs, Tibet, Kunlun, Karakorum, Tien Shan - is hindered by the dryness of their continental climate, but is facilitated by the enormous height.

Rice. 47. Distribution of permafrost

State change water bodies under the influence of economic activity. The huge water wealth of the mainland is intensively used in the economy. However, due to the uneven distribution of inland waters across the territory, some regions experience an extreme lack of water resources, in others there is a problem of excessive surface moisture.

The shortage of water resources is especially acute inside the continent - in the basin of internal flow. Farming and people's lives here are possible only with artificial irrigation - irrigation. Often the water of the rivers is withdrawn completely, depriving water bodies of internal flow. This causes a chain of environmental problems: soil salinization, increased wind erosion, desertification. Over the past decades, many small rivers and lakes have disappeared from the map of Eurasia, and some large rivers, for example Amu Darya And Syrdarya in Central Asia, they cannot carry their waters to the Aral Sea, which has turned into several small lakes because of this.

To remove excess moisture from the swampy woodlands of Europe and the lowlands of South and Southeast Asia, which are waterlogged by rains, drainage reclamation is carried out. . Often, drainage that does not take into account the hydrological regime of biocenoses entails a chain of negative environmental consequences. The continental climate is growing, peat bogs are being destroyed, plant and animal species are disappearing forever, small rivers and lakes are drying up, and soil erosion is intensifying.

Intensive management leads to pollution of surface and groundwater with pesticides, mineral and organic waste, synthetic substances, oil products. The “circulatory system” of the mainland “infected” with harmful substances, impregnating the surface rocks, transports these pollutants over long distances, spreading the “infection”, and then takes it to the World Ocean. Despite the fact that the most densely populated regions of Eurasia are located in the basins of the largest rivers, in many of these areas there is an acute shortage of water resources, including clean water.

Due to global warming, one of the reasons for which is economic activity human, there is a rapid degradation of permafrost, intensive melting of glaciers, which leads to a gradual increase in the level of the World Ocean.

Bibliography

1. Geography Grade 9 / Tutorial for the 9th grade of institutions of general secondary education with the Russian language of instruction / Edited by N. V. Naumenko/ Minsk "People's Asveta" 2011

A continent is a large landmass surrounded by seas and oceans. In tectonics, continents are characterized as sections of the lithosphere with a continental structure.

Mainland, continent or part of the world? What is the difference?

In geography, another term is often used, denoting the mainland - the continent. But the concepts of "mainland" and "continent" are not synonymous. IN different countries various points of view on the number of continents, called continental models, have been adopted.

There are several such models:

• In China, India, as well as in the English-speaking countries of Europe, it is customary to consider that continents 7 - Europe and Asia, they consider separately;
• In Spanish-speaking European countries, as well as in the countries of South America, they mean the division into 6 parts of the world - with a united America;
• in Greece and some countries of Eastern Europe, a model with 5 continents is adopted - only those where people live, i.e. except for Antarctica;
• in Russia and the countries of Eurasia adjacent to it, they traditionally designate 4 - continents united into large groups.

(The figure clearly shows different representations of continental models on Earth, from 7 to 4)

Continents

There are 6 continents in total on Earth. We list them in descending order by area size:

1. - the largest continent on our planet (54.6 million sq. km)
2. (30.3 million sq. km)
3. (24.4 million sq. km)
4. (17.8 million sq. km)
5. (14.1 million sq. km)
6. (7.7 million sq. km)

All of them are separated by the waters of the seas and oceans. Four continents have a land border: Eurasia and Africa are separated by the Isthmus of Suez, North and South America - the Isthmus of Panama.

Continents

The difference is that the continents do not have a land border. Therefore, in this case, we can talk about 4 continents ( one of the continental models of the world), also in descending order by size:

1. AfroEurasia
2. America

Parts of the world

The terms "mainland" and "continent" have a scientific meaning, but the term "part of the world" divides the land on a historical and cultural basis. There are 6 parts of the world, only unlike the continents, Eurasia differs by Europe And Asia, but North and South America are defined together as one part of the world America:

1. Europe
2. Asia
3. America(both North and South), or New World
4. Australia and Oceania

Speaking of parts of the world, they mean the islands adjacent to them.

The difference between the mainland and the island

The definition of the mainland and the island is the same - a part of the land washed by the waters of the ocean or seas. But there are significant differences.

1. Size. Even the smallest continent, Australia, is much larger in area than the world's largest island, Greenland.

(Formation of the Earth's continents, a single continent of Pangea)

2. Education. All continents have a tiled origin. According to scientists, there was once a single continent - Pangea. Then, as a result of the split, 2 continents appeared - Gondwana and Laurasia, which later split into 6 more parts. The theory is confirmed both by geological surveys and by the shape of the continents. Many of them can be put together like a puzzle.

Islands are formed in many ways. There are those that, like the continents, are located on the fragments of the most ancient lithospheric plates. Others are formed from volcanic lava. Still others - as a result of the activity of polyps (coral islands).

3. Habitability. All continents are inhabited, even the harsh climatic conditions Antarctica. Many islands are still uninhabited.

Characteristics of the continents

- the largest continent, occupying 1/3 of the land. Two parts of the world are located here at once: Europe and Asia. The border between them runs along the line of the Ural Mountains, the Black and Azov Seas, as well as the straits connecting the Black and Mediterranean Seas.

This is the only continent that is washed by all the oceans. The coastline is indented, it forms a large number of bays, peninsulas, islands. The mainland itself is located immediately on six tectonic platforms, and therefore the relief of Eurasia is incredibly diverse.

Here are the most extensive plains, the highest mountains (the Himalayas with Mount Everest), the deepest lake (Baikal). This is the only continent where all climatic zones (and, accordingly, all natural zones) are represented at once - from the arctic with its permafrost to the equatorial with its sultry deserts and jungles.

¾ of the world's population lives on the mainland, 108 states are located here, of which 94 have the status of independent.

- the hottest continent on Earth. It is located on an ancient platform, so most of the area is occupied by plains, mountains are formed along the edges of the mainland. Africa is home to the longest river in the world, the Nile, and the largest desert, the Sahara. Climate types presented on the mainland: equatorial, subequatorial, tropical and subtropical.

Africa is usually divided into five regions: North, South, West, East and Central. There are 62 countries on the mainland.

It is washed by the waters of the Pacific, Atlantic and Arctic oceans. The result of the movement of tectonic plates was a heavily indented coastline of the mainland, with a huge number of bays, straits, bays and islands. The largest island is in the north (Greenland).

The Cordillera Mountains stretch along the western coast, and the Appalachians along the eastern coast. central part occupies a vast plain.

All climatic zones are represented here, except for the equatorial one, which determines the diversity of natural zones. Most rivers and lakes are located in the northern part. largest river- Mississippi.

The indigenous people are Indians and Eskimos. Currently, 23 states are located here, of which only three (Canada, the United States and Mexico) are on the mainland itself, the rest are on the islands.

Washed by the Silent and Atlantic Oceans. Along the west coast stretches the world's longest mountain system - the Andes, or South American Cordillera. The rest of the mainland is occupied by plateaus, plains and lowlands.

This is the rainiest continent, since most of it is located in the equator zone. Here is the largest and most abundant river in the world - the Amazon.

The indigenous people are the Indians. Currently, there are 12 independent states on the territory of the mainland.

- the only continent on the territory of which there is only 1 state - the Commonwealth of Australia. Most of the mainland is occupied by plains, mountains are located only along the coast.

Australia is a unique continent with the largest number of endemic animals and plants. The indigenous people are Australian Aborigines, or Bushmen.

- the southernmost continent, completely covered with ice. The average thickness of the ice cover is 1600 m, the largest is 4000 m. If the ice in Antarctica melted, the level of the world's oceans would immediately rise by 60 meters!

Most of the mainland is occupied by an icy desert, life is glimmering only on the coasts. Antarctica is also the coldest continent. In winter, temperatures can drop below -80 ºC (record -89.2 ºC), in summer - up to -20 ºC.