What is a lake? Lakes by origin Types of lakes, origin, characteristics.

There are more than two million freshwater and salt lakes in Russia. The largest lakes in the European part of the country include Ladoga (17.87 thousand km²) and Onega (9.72 thousand km²) in the north-west, Lake Peipus (3.55 thousand km²) on the Estonian border, as well as the Rybinsk Reservoir ( 4.58 thousand km²) on the Volga north of Moscow.

Narrow lakes from 160 to 320 km in length, located behind dams on the Don, Volga and Kama. In Siberia, similar artificial lakes are located on the upper Yenisei and its tributary the Angara, where the 570 km long Bratsk reservoir is one of the largest in the world. But they are all insignificant compared to Lake Baikal, the largest reservoir of fresh water on the planet. 636 km long and with an average width of 50 km, Baikal's surface area is 31.72 thousand km² and its maximum depth is 1642 m.

There are also countless smaller lakes, located mainly in the poorly drained lowlands of the Russian and West Siberian Plains, especially in the more northern regions. Some of them reach significant sizes, in particular, Lake Beloe (1.29 thousand km²), Topozero (0.98 thousand km²), Vygozero (0.56 thousand km²) and Lake Ilmen (0.98 thousand km²) on the territory of the European north-west of the country, and Lake Chany (1.4-2 thousand km²) in south-west Siberia.

List of the largest lakes in Russia

We present to your attention the 10 largest lakes in the Russian Federation with descriptions, photos and geographical location on the map of the country.

Caspian Sea

The Caspian Sea is the world's largest inland body of water (area: 371 thousand km²). It is called a sea, not a lake, because the ancient Romans, who arrived in this region, discovered that its water was salty, and called it a sea after the Caspian tribes who lived near the shores of the lake. The Caspian Sea borders the following five countries: Russia, Kazakhstan, Turkmenistan, Azerbaijan and Iran. The main river feeding the lake is the Volga, which provides about 80% of the water inflow of the Caspian Sea, and the remaining 20% ​​comes from other smaller rivers.

The Caspian Sea is rich in oil and natural gas deposits, but their extraction is under development. The extraction process is also hampered by the problem of dividing the lake’s natural resources between the five countries bordering it. The Caspian Sea and the deltas of the rivers flowing into it are home to about 160 species and subspecies of fish from 60 genera. About 62% of species are endemic.

Baikal

Baikal is the deepest (1642 m), oldest (25-35 million years) and most voluminous (23.6 thousand km³) of all the lakes in the world, it is a superstar reservoir in the fields of hydrology, geology, ecology and history. Today Lake Baikal contains about 20 percent of the fresh water on the Earth's surface, which is comparable in volume to the entire Amazon River basin. Baikal has 27 islands, including one more than 70 km in length (Olkhon Island).

The shores of the lake are home to more than 1,500 species of animals, 80% of which are found nowhere else on the planet. The most famous representative of the Baikal fauna is the seal, which lives exclusively in fresh water. According to some reports, the population of seals is about 100,000 individuals. Also near the lake there are such large predators as do wolves, which occupy the top position of the Siberian food chain, feeding on deer, birds, rodents and smaller predators.

Ladoga lake

Lake Ladoga is the largest freshwater lake in Europe, located in northwestern Russia, 40 km east of St. Petersburg. The area of ​​the lake is 17.87 thousand km², the volume is 838 km³, and the maximum depth at a point west of the island of Valaam it reaches 230 m.

The lake depression appeared under the influence of glaciers. The northern shores are mostly high and rocky, and are separated by deep, ice-covered bays. The southern shores have many sandy or rocky beaches, mostly low, slightly concave, overgrown with willow and alder. In some places there are ancient coastal embankments covered with pine trees. The largest tributaries are the Volkhov, Svir and Vuoksa rivers.

48 different species of fish were found in the lake, of which the most common are roach, carp, bream, pike perch, perch and smelt. Of the 48 species, 25 are of commercial importance and 11 are classified as important food fish.

Lake Ladoga also serves as a key stopover for migratory birds along the North Atlantic Flyway, which typically mark the arrival of spring.

Lake Onega

Lake Onega is the second largest lake in Europe, located in the north-west of the European part of Russia, between Lake Ladoga and the White Sea. It covers an area of ​​9.72 thousand km², 248 km in length and up to 83 km in width. The greatest depth is about 127 m.

The lake basin was formed by the movement of the earth's crust and glaciers. The high rocky shores in the north and northwest are composed of laminated granite and covered with forest. There are deep bays in Petrozavodsk, Kondopoga and Pevenets. The southern shores are narrow, sandy, often swampy or flooded. Lake Onega has about 1,650 islands, covering a total of about 260 km², usually in the northern and northwestern bays.

The lake is home to more than 40 species of fish, including vendace (a small member of the salmon family), smelt, burbot bream, pike, perch, roach and salmon. Many fish species have significant economic value.

Taimyr

Taimyr is the second (after Baikal) largest lake in the Asian part of Russia, located in the central regions of the Taimyr Peninsula. It is located south of the Byrranga Mountains, in the zone.

The lake and tundra area is a popular destination for birds such as geese, swans, ducks, ruffed buzzards, peregrine falcons and snowy owls. Lives in Lake Taimyr a large number of fish, including grayling, muksun, char and whitefish. Although the area is relatively remote, stocks of certain commercial fish species are still being depleted.

Taimyr is famous for the largest population of reindeer in Eurasia. Animals such as argali, arctic fox, wolf and lemmings are also found in this region. In 1975, the area was reintroduced.

The lake and its surroundings have been included in the Taimyr Nature Reserve since 1983. Scientists have discovered plutonium in the lake sediment, which is believed to have entered Taimyr via wind-borne radioactive particles from nuclear tests conducted on Novaya Zemlya during the Cold War.

Khanka

Lake Khanka has an area of ​​4 thousand km², of which approximately 97% is located in Russia. The maximum depth of the lake is 10.6 m, and the average volume is 18.3 km². The lake is fed by 23 rivers, 8 of which are in China, and the rest in the Russian Federation. The only outflow is the Sungacha River, which flows east to the Ussuri River, which forms the international border, and flows north where it joins the Amur River.

Khanka is famous for being home to the highest diversity of birds in the entire temperate zone of Eurasia. At least 327 species of nesting, wintering and migratory birds have been observed in the lake area.

Lake Peipus-Pskov

Lake Peipus-Pskov is the largest transboundary and fifth (after Ladoga, Onega, Swedish Vänern and Finnish Saimaa) largest lake in Europe, located on the border between Estonia and Russia. It occupies 3.6% of the total area of ​​the Baltic Sea basin. A total of 30 islands are located on Lake Peipsi, and another 40 in the delta of the Velikaya River. Most of them rise only 1-2 m above the water level, and often suffer from floods.

About 54 species of coastal aquatic plants grow in the Lake Peipus basin, including reeds, calamus, reeds and various grasses. The waters of the lake are home to 42 species of fish, such as smelt, vendace, bream, perch, pike, roach and whitefish. Wetlands provide important nesting and feeding grounds for migratory birds such as swans, geese and ducks that migrate from the White Sea to the Baltic Sea. The region is home to one of the largest swallow colonies in Estonia.

Uvsu-Nur

Uvsu-Nur is the largest lake in Mongolia by surface area (3.35 thousand km²), as well as the largest salt lake in the country. The Uvs-Nur basin is one of the most important biodiversity poles in Eurasia. Although most of the lake is in Mongolia, its northeastern shores are located in the Tyva Republic of the Russian Federation.

The lake is shallow, very salty, and is the remnant of a large sea that existed several thousand years ago. The basin covers an area of ​​about 70 thousand km² and represents one of the best preserved natural steppe landscapes on the continent. This is where the northernmost part of the desert and the southernmost part of the tundra meet.

Reed and freshwater river deltas serve as resting and nesting sites for numerous migratory birds. More than 220 species of birds can be found around the lake, including black stork, osprey, white-tailed eagle, whooper and black-headed gull. About 29 different species of fish live in the waters of the lake, one of which is suitable for human consumption. The mountainous region is home to Mongolian gerbils, wild sheep and Siberian ibex.

Vats

Although Lake Chany is not very well known outside of Siberia, it is one of the largest lakes in the country. Chany is a shallow lake with salty and constantly fluctuating water, the level of which can change from season to season and from year to year. The lands of the lake basin serve as pastures for cattle.

In terms of area, Beloe is the second (after Onega) natural lake in the Vologda region, and the third (after the Rybinsk reservoir). It is one of the ten largest natural lakes in Europe. The lake has a relatively round shape with a diameter of 46 km. Its area is 1.29 thousand km², and the basin area is about 14 thousand km².

The lake is famous for its fish stocks, the most famous delicacy being Belozersk smelt. The food supply and high oxygen levels create favorable conditions for the life of many species. The following types of fish are common in the waters of the lake: perch, pike, bream, ruffe, sabrefish, roach, bleak, burbot, chub, rudd, whitefish, ide, tench, asp, dace and gudgeon).

Table of the 10 largest lakes in Russia

Lake name	Area, km²	Volume, km³	Dimensions, km	Maximum depth, m	Average depth, m
Caspian Sea	371000	78200	1200 by 435	1025	208
Baikal	31722	23615	636 by 79.5	1642	744,4
Ladoga lake	17870	838	219 by 125	230	46,9
Lake Onega	9720	285	248 by 83	127	30
Taimyr	4560	12,8	-	26	2,8
Khanka	4070	18,3	90 to 45	10,6	4,5
Lake Peipus-Pskov	3555	25	width 50	15	7,1
Uvsu-Nur	3350	35,7	85 to 80	20	10,1
Vats	1400-2000	-	91 to 88	7	2,1
White Lake	1290	5,2	46 by 33	20	4

When we all hear the word “lake,” we imagine some quiet body of water surrounded by a visible shore line. There will be no such lakes in this article. Have you ever heard of lakes that are subject to storm surges and are larger than some seas?

I present to your attention a selection of “the largest lakes in the world,” which includes the 10 largest lakes. Read, rate, leave comments and feedback in discussions.

Sasha Mitrakhovich 22.03.2016 15:06

The largest lake in the world- Caspian Sea.

The Caspian Sea tops the ranking - despite the fact that it is called a sea, in fact it is the largest endorheic lake on the planet. It is located at the junction of Europe and Asia, and is called a sea only because of its size. The Caspian Sea is an endorheic lake, and the water in it is salty, from 0.05 ‰ near the mouth of the Volga to 11-13 ‰ in the southeast.

The Caspian Sea is shaped like the Latin letter S, its length from north to south is approximately 1200 kilometers, from west to east - from 195 to 435 kilometers, on average 310-320 kilometers.

The Caspian Sea is conventionally divided according to physical and geographical conditions into 3 parts - the Northern Caspian, the Middle Caspian and the Southern Caspian. The conditional border between the Northern and Middle Caspian Seas runs along the line Chechen (island) - Tyub-Karagansky Cape, between the Middle and Southern Caspian Seas - along the line Zhilaya (island) - Gan-Gulu (cape). The area of ​​the Northern, Middle and Southern Caspian Sea is respectively 25, 36, 39 percent of the total area of ​​the Caspian Sea.

The length of the coastline of the Caspian Sea is estimated at approximately 6,500 - 6,700 kilometers, with islands - up to 7,000 kilometers. The shores of the Caspian Sea in most of its territory are low-lying and smooth. In the northern part, the coastline is indented by water channels and islands of the Volga and Ural deltas, the banks are low and swampy, and the water surface in many places is covered with thickets.

The east coast is dominated by limestone shores adjacent to semi-deserts and deserts. The most winding shores are on the western coast in the area of ​​the Absheron Peninsula and on the eastern coast in the area of ​​the Kazakh Gulf and Kara-Bogaz-Gol.

The territory adjacent to the Caspian Sea is called the Caspian region.

Area and volume of water Caspian Sea varies significantly depending on fluctuations in water level. At a water level of 26.75 m, the area is approximately 371,000 km square kilometers, the volume of water is 78,648 cubic kilometers, which is approximately 44 percent of the world's lake water reserves. The maximum depth of the Caspian Sea is in the South Caspian depression, 1025 meters from its surface level. In terms of maximum depth, the Caspian Sea is second only to Baikal (1620 m) and Tanganyika (1435 m). The average depth of the Caspian Sea is 208 meters. At the same time, the northern part of the Caspian Sea is shallow, its maximum depth does not exceed 25 meters, and the average depth is 4 meters.

Sasha Mitrakhovich 22.03.2016 15:19

Confidently secured second place among lake superior- the largest, deepest and coldest of the Great Lakes and, concurrently, the largest freshwater lake in the world.

In the north, Lake Superior is bounded by the Canadian province of Ontario, in the west by the American state of Minnesota, and in the south by the states of Wisconsin and Michigan.

The basins of Lake Superior and the northern part of Lake Huron were developed in the crystalline rocks of the southern part of the Canadian Shield, the basins of the remaining lakes were developed in the limestone, dolomite and sandstone of the Paleozoic North American Platform. Basin Lake Superior formed as a result of tectonic movements, pre-glacial river and glacial erosion.

The origin of the water mass of Lake Superior is associated with the melting of the ice sheet, during the retreat of which a number of large lakes were formed in this area, which repeatedly changed their outlines.

In the northern part of the Great Lakes, the coastline is dissected, the islands and shores (up to 400 m high) are rocky, steep, very picturesque, especially the shores of Lake Superior and the northern part of Lake Huron.

Fluctuations in the level of Lake Superior are artificially regulated for the purposes of navigation, energy, etc. The amplitude of seasonal fluctuations is 30-60 cm, the highest level is observed in summer, the lowest in winter. Short-term fluctuations in level caused by strong surge winds and seiches reach 3-4 m, tidal height is 3-4 cm

Sasha Mitrakhovich 22.03.2016 15:26

The third is Lake Victoria, a lake in East Africa, in Tanzania, Kenya and Uganda. Located in the tectonic trough of the East African Platform, at an altitude of 1134 m. It is the 2nd largest freshwater lake in the world after Lake Superior and the largest lake in Africa

The lake was discovered and named in honor of Queen Victoria by British traveler John Henning Speke in 1858.

Square Lake Victoria 68 thousand square kilometers, length 320 km, maximum width 275 km. It is part of the Victoria Reservoir. Many islands. The high-water Kagera River flows in and the Victoria Nile River flows out. The lake is navigable, local residents They are engaged in fishing on it.

The northern coast of the lake crosses the equator. The lake, with a maximum depth of 80 m, is a fairly deep lake.

Unlike its deep-sea neighbors Tanganyika and Nyasa, which lie within the African gorge system, Lake Victoria fills the shallow depression between the eastern and western sides of the Great Gorge valley. The lake receives a huge amount of water from rain, more than from all its tributaries.

30 million people live in the vicinity of the lake. On the southern and western shores of the lake live the Haya people, who knew how to grow coffee long before the arrival of Europeans. Main ports: Entebbe (Uganda), Mwanza, Bukoba (Tanzania), Kisumu (Kenya), near the northern coast of Kampala, the capital of Uganda.

Sasha Mitrakhovich 22.03.2016 15:30

Lake Huron is the fourth largest among. This lake is in the USA and Canada, one of the North American Great Lakes. Located east of Lake Michigan, connected to it by the Strait of Mackinac. From a hydrographic point of view, Michigan and Huron form a single system (they are connected by the Strait of Mackinac), but geographically they are considered to be separate lakes.

The area of ​​Huron is about 59.6 thousand square kilometers (the second largest among the Great Lakes). The surface height above sea level is about 176 m (same as Michigan), the depth is up to 229 m.

The states of Michigan and the Canadian province of Ontario have access to the lake. The main ports on Huron are Saginaw, Bay City, Alpina (USA) and Sarnia (Canada).

The name of the lake, introduced by the French, comes from the name of the Huron Indian tribe. Manitoulin is located on Huron - the most big Island world, located in a fresh lake.

Sasha Mitrakhovich 22.03.2016 15:37

In the middle of the list, in 5th place among is lake michigan- one of the North American Great Lakes.

The only Great Lakes located entirely within the United States. Located south of the lake The upper one is connected to Lake Huron by the Strait of Mackinac, with the Mississippi River system - the Chicago - Lockport Canal.

From a hydrographic point of view, Michigan and Huron form a single system, but geographically they are considered to be separate lakes.

Square Michigan- about 57,750 km2 (the third largest among the Great Lakes), length about 500 km, width about 190 km. The surface height above sea level is 177 m (same as Huron), the depth is up to 281 m. It is covered with ice for about four months a year. Islands - Beaver, North Manitou, South Manitou.

The states of Michigan, Indiana, Illinois and Wisconsin have access to the lake. Big cities on Lake Michigan include Chicago, Evanston and Highland Park (IL), Milwaukee and Green Bay (WI), and Gary and Hammond (IN).

The name of the lake comes from the word mishigami, meaning “big water” in the Ojibwa Indian language. The first European to discover the lake was the Frenchman Jean Nicolet in 1634.

Sasha Mitrakhovich 22.03.2016 15:42

Sixth among is Aral Sea.

The Aral Sea is an endorheic salt lake in Central Asia, on the border of Kazakhstan and Uzbekistan. Since the 1960s of the 20th century, sea level (and the volume of water in it) has been rapidly declining due to the withdrawal of water from the main feeding rivers Amu Darya and Syr Darya for irrigation purposes. Before the start of shallowing, the Aral Sea was the fourth largest lake in the world.

Collector-drainage waters flowing from the fields into the bed of the Syr Darya and Amu Darya have caused deposits of pesticides and various other agricultural pesticides, appearing in places on 54 thousand square kilometers of the former seabed covered with salt. Dust storms carry salt, dust and toxic chemicals up to 500 km. Sodium bicarbonate, sodium chloride and sodium sulfate are airborne and destroy or retard the development of natural vegetation and crops. The local population suffers from a high prevalence of respiratory diseases, anemia, cancer of the larynx and esophagus, and digestive disorders. Liver and kidney diseases and eye diseases have become more frequent.

In 2001, as a result of a drop in water level, Vozrozhdenie Island connected with the mainland. On this island, the Soviet Union tested bacteriological weapons: the causative agents of anthrax, tularemia, brucellosis, plague, typhoid, smallpox, as well as botulinum toxin were tested here on horses, monkeys, sheep, donkeys and other laboratory animals. This is the reason for fears that deadly microorganisms have remained viable, and infected rodents may spread them to other regions.

According to scientists' calculations, it is no longer possible to save the Aral Sea. Even if we completely abandon the intake of water from the Amu Darya and Syr Darya, the previous water level in it will be restored no earlier than in 200 years.

The Aral Sea once occupied 68 thousand square kilometers and was the fourth largest in area in the world. Now its area is about 10% of that recorded in the 60s of the last century. Photos from 1989 and 2003:

From the 1950s to the present, projects have been repeatedly proposed to build a canal to transfer water from the Ob basin to the Aral Sea basin, which would significantly develop the economy of the Aral region (in particular, agriculture) and partially revive the Aral Sea. Such construction will require very large material costs (on the part of several states - Russia, Kazakhstan, Uzbekistan), so there is no talk yet about the practical implementation of these projects.

Some scientists predict the Aral Sea will completely disappear by 2020...

Sasha Mitrakhovich 22.03.2016 15:47

Lake Tanganyika- a large lake in Central Africa. This is one of and equally ancient in origin. In terms of volume and depth, Tanganyika ranks second after Lake Baikal. The shores of the lake belong to four countries - the Democratic Republic of the Congo, Tanzania, Zambia and Burundi.

The length of the lake is about 650 km, width is 40-80 km. Area 34 thousand sq. km. It lies at an altitude of 773 meters above sea level in the tectonic basin of the East African Rift Zone. Coastal landscapes, as a rule, consist of huge rocks and only on the eastern side the shores are gentle. On the west coast, the steep sidewalls of the East African Rift Zone that form the coastline reach 2000 m in height. The coastline is dotted with bays and bays. The largest of them is Burton Bay. The lake is fed by several tributaries. The only river that flows out is the Lukuga, which begins in the middle part of the west coast and flows west, connecting with the Zaire River, which flows into the Atlantic.

The lake is home to hippopotamuses, crocodiles, and many waterfowl. Fishing and shipping are well developed.

The antiquity of the lake and the long period of isolation resulted in the development of a large number of endemic organisms, including those from the family Cichlidae (cichlids). Of the more than 200 species of fish found in the lake, about 170 are endemic.

Tanganyika is inhabited to approximately a depth of 200 m; below this level there is a high concentration of hydrogen sulfide and there is no life until the very bottom. This layer of the lake is a huge “burial ground” consisting of organic silt and sedimentary mineral compounds.

The water temperature of Tanganyika varies strictly among layers. Thus, in the upper layer the temperature ranges from 24 to 30 degrees, with a decrease at greater depths. Due to different densities of water and the absence of bottom current, the layers do not mix, and the temperature on the lower horizons reaches only 6-8 degrees.

The depth of the temperature jump layer is about 100 m. The water of Tanganika is very transparent (up to 30 m). Many salts are dissolved in it in small concentrations, so its composition resembles highly diluted sea salt. Water hardness (mainly caused by magnesium salts) ranges from 8 to 15 degrees. Water has an alkaline reaction, pH 8.0 - 9.5.

- a body of water formed on the surface of the land in a natural depression. Since the lake does not have a direct connection with the ocean, it is a body of slow water exchange.

The total area of ​​lakes on the globe is about 2.7 million km 3, which is 1.8% of the land surface.

Main characteristics of the lake:

• lake area - water surface area;
• coastline length - water edge length;
• lake length - the shortest distance between the two most distant points on the coastline, average width - area to length ratio;
• lake volume - volume of the basin filled with water;
• average depth - ratio of water mass volume to area;
• maximum depth - is found by direct measurements.

The largest lake on Earth by water surface area is the Caspian (376 thousand km 2 at a water level of 28 m), and the deepest is Baikal (1620 m).

The characteristics of the largest lakes in the world are given in table. 1.

Each lake has three interconnected components: the basin, the water mass, the vegetation and fauna of the reservoir.

Lakes of the world

By position In the lake basin, lakes are divided into above-ground and underground. The latter are sometimes filled with juvenile water. The subglacial lake in Antarctica can also be classified as an underground lake.

Lake basins could be like endogenous, so exogenous origin, which most significantly affects their size, shape, and water regime.

The largest lake basins. They can be located in tectonic depressions (Ilmen), in foothill and intermountain troughs, in grabens (Baikal, Nyasa, Tanganyika). Most large lake basins have a complex tectonic origin; both fault and fold movements are involved in their formation (Issyk-Kul, Balkhash, Victoria, etc.). All tectonic lakes are large in size, and most have significant depths and steep rocky slopes. The bottoms of many deep lakes lie below the level of the World Ocean, and the surface of the lake lies above the level. Certain patterns are observed in the location of tectonic lakes: they are concentrated along faults in the earth’s crust or in rift zones (Syrian-African, Baikal), or frame shields: along the Canadian shield are located the Great Bear Lake, the Great Slave Lake, the Great North American Lakes, along the Baltic Shield — Onega, Ladoga, etc.

Lake name	Maximum surface area, thousand km 2	Altitude above sea level, m	Maximum depth, m
Caspian Sea
				North America
Victoria
				North America
				North America
Aral Sea
Tanganyika
Nyasa (Malawi)
Big Bear				North America
Great Slave				North America
				North America
Winnipeg				North America
				North America
Ladoga
Maracaibo				South America
Bangweulu
Onega
Tonle Sap
Nicaragua				North America
Titicaca				South America
Athabasca				North America
				North America
Issyk-Kul
Bolshoye Solenoye				North America
				Australia

Volcanic lakes occupy craters and calderas of extinct volcanoes (Kronopkoye Lake in Kamchatka, lakes in Java, New Zealand).

Along with lake basins created by internal processes of the Earth, there are very numerous lake baths formed due to exogenous processes.

Among them the most common glacial lakes on the plains and in the mountains, located both in basins plowed by glaciers and in depressions between hills with uneven deposition of moraine. The lakes of Karelia and Finland, which are elongated in the direction of glacier movement from northwest to southeast along tectonic cracks, owe their origin to the destructive activity of ancient glaciers. In fact, Ladoga, Onega and other lakes have a mixed glacial-tectonic origin. Glacial basins in the mountains include numerous, but small carts lakes located in bowl-shaped depressions on mountain slopes below the snow line (in the Alps, Caucasus, Altai), and trogous lakes - in trough-shaped glacial valleys in the mountains.

The uneven accumulation of glacial deposits on the plains is associated with lakes among hilly and moraine terrain: in the north-west of the East European Plain, especially in the Valdai Upland, in the Baltic states, Poland, Germany, Canada and the northern USA. These lakes are usually shallow, wide, with lobed shores, with islands (Seliger, Valdai, etc.). In the mountains, such lakes arose on the site of former glacier tongues (Como, Garda, Würm in the Alps). In areas of ancient glaciations, there are numerous lakes in the hollows of the runoff of melted glacial waters; they are elongated, trough-shaped, usually small and shallow (for example, Dolgoe, Krugloe - near Moscow).

Karst lakes are formed in places where rocks are leached by underground and partly surface waters. They are deep, but small, often round in shape (in the Crimea, the Caucasus, in the Dinaric and other mountainous regions).

Suffosion lakes are formed in basins of subsidence origin at the site of intensive removal of fine earth and mineral particles by groundwater (southern Western Siberia).

Thermokarst Lakes appear when permafrost soil melts or ice melts. Thanks to them, the Kolyma Lowland is one of the most lake regions in Russia. Many relict thermokarst lake basins are located in the north-west of the East European Plain in the former periglacial zone.

Aeolian lakes arise in blowing basins (Lake Teke in Kazakhstan).

Zaprudnye lakes are formed in the mountains, often after earthquakes, as a result of landslides and landslides blocking river valleys (Lake Sarez in the Murghab valley in the Pamirs).

In the valleys of lowland rivers, the most numerous are floodplain oxbow lakes of a characteristic horseshoe shape, formed as a result of meandering of rivers and subsequent straightening of channels; when rivers dry up, river lakes are formed in bochagas - reaches; in river deltas there are small ilmen lakes, in place of channels, often overgrown with reeds and reeds (ilmen lakes of the Volga delta, lakes of the Kuban flood plains).

On the low-lying coasts of the seas, coastal lakes are typical in place of estuaries and lagoons, if the latter are separated from the sea by sandy alluvial bridges: spits, bars.

A special type is organogenic lakes among swamps and coral buildings.

These are the main genetic types of lake basins, determined by natural processes. Their location on the continents is presented in Table. 2. But recently, more and more “man-made” lakes created by man have appeared - so-called anthropogenic lakes: lakes - reservoirs on rivers, lakes - ponds in quarries, in salt mines, on the site of peat mining.

By genesis of water masses There are two types of lakes. Some have water of atmospheric origin: precipitation, river and groundwater. Such lakes fresh, although in dry climates they may eventually become salty.

Other lakes were part of the World Ocean - these are relict salty lakes (Caspian, Aral). But even in such lakes the primary sea ​​water can be greatly transformed and even completely displaced and replaced by atmospheric waters (Ladozhskoe, etc.).

Table 2. Distribution of the main genetic groups of lakes by continent and part of the world

Genetic groups of lakes	Continents and parts of the world
	Western Europe	Foreign Asia	North America	South America		Australia
Glacial
Glacial-tectonic
Tectonic
Volcanic
Karst
Residual
Lagoon
Floodplain

Depending from water balance, t.s. According to the conditions of inflow and outflow, lakes are divided into drainage and drainageless. Lakes that discharge part of their waters in the form of river runoff - sewage; a special case of them are flowing lakes. Many rivers can flow into the lake, but only one flows out (the Angara from Lake Baikal, the Neva from Lake Ladoga, etc.). Lakes that do not drain into the World Ocean - drainless(Caspian, Aral, Bolshoye Solenoye). The water level in such lakes is subject to fluctuations of varying duration, which is primarily due to long-term and seasonal climate changes. At the same time, the morphometric characteristics of lakes and the properties of water masses change. This is especially noticeable on lakes in arid regions, which promise long cycles of climate moisture and aridity.

Lake waters, like other natural waters, are characterized by different chemical compositions and varying degrees of mineralization.

Based on the composition of salts in the water, lakes are divided into three types: carbonate, sulfate, and chloride.

By degree of mineralization lakes are divided into fresh(less than 1%o), brackish(1-24.7%c), salty(24.7-47%o) and mineral(more than 47%c). An example of a fresh lake is Baikal, the salinity of which is 0.1%, brackish - Caspian sea water - 12-13%, Bolshoye Solenoye - 137-300%, Dead Sea - 260-270%, in some years - up to 310%c.

The distribution of lakes with varying degrees of mineralization on the earth's surface shows geographic zonality, determined by the moisture coefficient. In addition, those lakes into which rivers flow are characterized by low salinity.

However, the degree of mineralization can vary within the same lake. For example, in the closed lake Balkhash, located in an arid zone, in the western part, where the river flows. Or, the water is fresh, but in the eastern part, which is connected to the western part only by a narrow (4 km) shallow strait, the water is brackish.

When lakes become oversaturated, salts begin to precipitate from the brine and crystallize. Such mineral lakes are called self-planting(for example, Elton, Baskunchak). Mineral lakes in which lamellar fine needles are deposited are known as mud.

Plays an important role in the life of lakes thermal regime.

Freshwater lakes of the hot thermal zone are characterized by the most warm water near the surface, it gradually decreases with depth. This temperature distribution over depth is called direct thermal stratification. Lakes in the cold thermal zone have the coldest (about 0 °C) and lightest water at the top almost all year round; With depth, the water temperature increases (up to 4°C), the water becomes denser and heavier. This temperature distribution over depth is called reverse thermal stratification. Lakes in the temperate thermal zone have variable stratification by season: direct in summer, reverse in winter. In spring and autumn there come moments when the vertical temperature is the same (4 °C) at different depths. The phenomenon of constant temperature over depth is called homothermy(spring and autumn).

The annual thermal cycle in temperate lakes is divided into four periods: spring heating (from 0 to 4 °C) is due to convective mixing; summer heating (from 4 °C to maximum temperature) - by molecular thermal conductivity; autumn cooling (from maximum temperature to 4 °C) - by convective mixing; winter cooling (from 4 to 0 °C) - again by molecular thermal conductivity.

In the winter period, freezing lakes have the same three phases as rivers: freezing, freezing, opening. The process of ice formation and melting is similar to rivers. Lakes tend to be covered with ice for 2-3 weeks longer than rivers in the region. The thermal regime of freezing salt lakes resembles that of seas and oceans.

Dynamic phenomena in lakes include currents, waves and seiches. Discharge currents occur when a river flows into a lake and water flows out of the lake into the river. In flowing lakes they can be traced throughout the entire water area of ​​the lake, in non-flowing lakes - in areas adjacent to the mouth or source of the river.

The height of the waves on the lake is less, but the steepness is greater compared to the seas and oceans.

The movement of water in lakes, along with dense convection, promotes mixing of water, penetration of oxygen into the lower layers, and uniform distribution of nutrients, which is important for the very diverse inhabitants of lakes.

By nutritional properties of water mass and the conditions for the development of life, lakes are divided into three biological types: oligotrophic, eutrophic, dystrophic.

Oligotrophic- low-nutrient lakes. These are big deep clear lakes with greenish-blue water rich in oxygen, so organic residues are intensively mineralized. Due to the small amount of nutrients, they are poor in plankton. Life is not rich, but there are fish and crustaceans. These are many mountain lakes, Baikal, Geneva, etc.

Eutrophic the lakes have a high content of nutrients, especially nitrogen and phosphorus compounds, are shallow (up to 1015 m), well heated, with brownish-green water. The oxygen content decreases with depth, which is why fish and other animals die in winter. The bottom is peaty or muddy with an abundance of organic residues. In summer, water blooms occur due to the strong development of phytoplankton. The lakes have a rich flora and fauna. They are most common in forest-steppe and steppe zones.

Dystrophic the lakes are poor in nutrients and oxygen and are shallow. The water in them is acidic, slightly transparent, and brown due to the abundance of humic acids. The bottom is peaty, there is little phytoplankton and higher aquatic vegetation, as well as animals. These lakes are common in heavily swampy areas.

In the last decade, due to the increased supply of phosphorus and nitrogen compounds from fields, as well as the discharge of wastewater from some industrial enterprises, eutrophication of lakes has been observed. The first sign of this unfavorable phenomenon is a strong bloom of blue-green algae, then the amount of oxygen in the reservoir decreases, silt forms, and hydrogen sulfide appears. All this will create unfavorable living conditions for fish, waterfowl, etc.

Evolution of lakes occurs in different ways in humid and dry climates: in the first case they gradually turn into swamps, in the second - into salt marshes.

In a humid (humid) climate, the leading role in filling the lake and turning it into a swamp belongs to vegetation, partly to the remains of the animal population, which together form organic remains. Temporary streams and rivers bring mineral deposits. Small lakes with gentle shores are overgrown by pushing vegetation ecological zones from the periphery to the center. Eventually the lake becomes a grassy, ​​low-lying marsh.

Deep lakes with steep banks overgrow differently: by growing from above alloys(swell) - a layer of living and dead plants. It is based on plants with long rhizomes (cinquefoil, cinquefoil, whitewing), and other herbaceous plants and even shrubs (alder, willow) settle on the network of rhizomes. The float first appears on the shores, protected from the wind, where there is no waves, and gradually advances onto the lake, increasing in power. Some plants die and fall to the bottom, forming peat. Gradually, only “windows” of water remain in the ravine, and then they disappear, although the basin is not yet filled with sediments, and only over time the raft closes with the peat layer.

In dry climates, lakes eventually become salt marshes. This is facilitated by an insignificant amount of precipitation, intense evaporation, a decrease in the influx of river water, and the deposition of solid sediments brought by rivers and dust storms. As a result, the water mass of the lake decreases, the level decreases, the area decreases, the concentration of salts increases, and even a fresh lake can first turn into a salt lake (Bolshoy Salt Lake in North America), and then into the salt marsh.

Lakes, especially large ones, have a softening effect on the climate of the surrounding areas: they are warmer in winter and cooler in summer. Thus, at coastal weather stations near Lake Baikal the temperature in winter is 8-10 °C higher, and in summer by 6-8 °C lower than at stations outside the influence of the lake. Air humidity near the lake is higher due to increased evaporation.

What is a lake? How is it different from a pond? How do they appear on Earth?

There are many wonders on our planet that we do not see only because we are in too much of a hurry. Roads have replaced nature travel, but once you stop and get out of the car, you can see a small pond.

Several hundred years ago, there may have been a collision with a “guest” from deep space. Or a supervolcano erupted. Nature leaves traces of the past under our feet; it’s up to you to read them or not.

What is a lake and what are its signs

The name of this type of reservoir translated from Old English (sounds like “laka”) is translated as pond or pool. From other languages ​​it can be translated as puddle, stream and even waterway.

The main problem in the definition is the confusion of the natural source of fresh (salt) water described here with an ordinary pond. To exclude such a connection, some definitions are interpreted to indicate the size of the source from two to five hectares.

No matter what size the lake is, it has the main difference from rivers and seas is isolation. Not even the largest lake is connected to the ocean. As a rule, it is surrounded by land along its perimeter.

The bulk of lakes on planet Earth are filled with fresh water and have a drainage system.

Reservoirs where nature provides for the outflow of water in the form of rivers are called wastewater. If the water balance is maintained solely by evaporation and penetration underground, then they are called drainless.

Maline Lake (Canada)

The largest number of lakes are in Canada (there are about 32 thousand) and Russia (more than 2 million). Beautiful lake landscapes can be found in Finland (190 thousand).

In nature there are reservoirs of artificial origin created for agriculture, decorative and industrial purposes.

Types and classification of lakes

Scientists classify lakes into several types.

By origin:

1. Tectonic– lakes of tectonic origin are formed as a result of deformation of the earth’s crust.
   The most famous is located on the territory of our country - lake. Baikal. This includes the lakes of the Caspian basin. Sometimes the soil simply subsides, forming thermokarst lakes.
2. Volcanic– occupying local volcanic depressions. For example, in craters (Craters) volcanic calderas (Calderas). Over time, such irregularities are filled with natural precipitation.

   

   Crater Lake in Oregon

   The creation process occurs quite quickly due to evaporation or the release of groundwater. Sometimes both lake names are mixed into one. An example is Crater Lake in Oregon, in the caldera of Mount Mazama.

3. Glacial– created under the direct influence of glaciers or continental glaciers. A wide variety of glacial processes create closed basins. Subspecies – karids.
   On the world map, something similar can be found in Antarctica - Lake Vostok.
4. Floodplain– form where sediment from a tributary dams the main river.
   Estuary lakes of the Azov Sea. Sometimes large seas dry out, forming residual ones.
5. Landslides– lakes are common in mountainous areas where there was an earthquake.

   

   Quake Lake in North America

   Although landslide lakes can be large and quite deep, they are short-lived. Quake in North America, Montana.

6. Aeolian- These are lakes created by the wind. Example - lake. Moses Lake, Washington.
7. Coastal– are formed due to blockages of beach ridges by longline and other currents. Oz. Beregovoe, Kemerovo region, Russia.
8. Organic– created by the actions of plants and animals.
9. Peat- this is a form of organic lake - lake. Torfyanoe, Moscow, Russia.
10. Anthropogenic- These are artificially created lakes formed by human activity. They may be the result of deliberate damming of rivers and streams.
    An example is a lake in Altai (Russia) near the Turquoise Katun tourist camp.
11. Meteoric– lakes created by catastrophic extraterrestrial impacts of either a meteorite or an asteroid.
    Example - lake. Yanisjarvi, Russia, Republic of Karelia.

By type of mineralization:

By nutritional value:

By chemical composition:

Characteristics of famous lakes of the world in the table

The table provides a brief description of the most famous lakes in the world.

Conclusion

From the school course it is clear to us that most of the planet is covered with water. Some of them are deep lakes (like Baikal), some are shallow and very salty (like Sol-Iletsk). But any of them is a beautiful creation of the material world of the Earth, which sometimes tells us that nature is the most talented architect of the world in which we live.

A lake is a component of the hydrosphere, which is a naturally occurring body of water filled within a lake bowl (lake bed) with water and not having a direct connection with the sea (ocean). Lakes are the subject of study of the science of limnology.

From the point of view of planetology, a lake is an object that exists stably in time and space, filled with a substance in the liquid phase, the dimensions of which occupy an intermediate position between the sea and the pond.

From a geographic point of view, a lake is a closed depression of land into which water flows and accumulates. Lakes are not part of the World Ocean.

Although the chemical composition of lakes remains constant for a relatively long time, unlike a river, the substance filling it is renewed much less frequently, and the currents present in it are not the predominant factor determining its regime. Lakes regulate river flow by retaining hollow waters in their basins and releasing them at other times. Chemical reactions occur in lake waters. Some elements move from water to bottom sediments, others - vice versa. In a number of lakes, mostly without drainage, the concentration of salts increases due to water evaporation. The result is significant changes in the mineralization and salt composition of lakes. Due to the significant thermal inertia of the water mass large lakes soften the climate of adjacent areas, reducing annual and seasonal fluctuations in meteorological elements.

The shape, size and topography of the bottom of lake basins change significantly with the accumulation of bottom sediments. The overgrowing of lakes creates new forms of relief, flat or even convex. Lakes and, especially, reservoirs often create a backwater of groundwater, causing swamping of nearby land areas. As a result of the continuous accumulation of organic and mineral particles in lakes, thick layers of bottom sediments are formed. These deposits are modified with the further development of reservoirs and their transformation into swamps or dry land. Under certain conditions, they transform into rocks of organic origin.

Lake classification

Based on their origin, lakes are divided into:

• Tectonic: formed by filling cracks in the earth's crust. A striking example of a tectonic lake is Lake Baikal.
• Glacial: formed by a melting glacier. A typical glacial lake left over from the last ice age is Arbersee, located at the foot of the Great Arber mountain (1456 m) - the highest mountain in the Bohemian Forest.
• River(or old women).
• Primorskie(lagoons and estuaries). The most famous lagoon is the Venetian lagoon, located in the northern part of the Adriatic Sea.
• Failed(karst, thermokarst). A feature of some sinkhole lakes is their periodic disappearance and reappearance, depending on the peculiar dynamics of groundwater. A typical representative is Lake Ertso in South Ossetia.
• Dammed: formed when part of a mountain collapses (for example, Lake Ritsa in Abkhazia).
• Mountain: located in mountain basins.
• Crater: located in the craters of extinct volcanoes and explosion pipes. In Europe, similar lakes are located in the Eifel region (Germany). Near them there are weak manifestations of volcanic activity in the form of hot springs.
• Artificial(reservoirs, ponds). The creation of such lakes can be an end in itself, for example, for creating reservoirs for various purposes. Often this creation is associated with more or less significant excavation work. But in some cases, such lakes arise as a side effect of such work, for example, in mined-out quarries.

According to their position, lakes are divided into (in relation to planet Earth):

• Ground, the waters of which take an active part in the water cycle in nature and underground waters, the waters of which, if they take part in it, are only indirect. Sometimes these lakes are filled with juvenile, that is, native water.
• Underground. The subglacial lake in Antarctica can also be classified as underground lakes.

According to water balance, lakes are divided into:

• Sewage(have a drainage, mainly in the form of a river).
• Drainless(they do not have surface runoff or underground drainage of water to neighboring watersheds. Water consumption occurs due to evaporation).

By type of mineralization

• fresh;
• ultra-fresh

mineral (salty).

• brackish
• salty

According to the chemical composition of the water, mineral lakes are divided into

• carbonate (soda)
• sulfate (bitter-salty)
• chloride (salty)

Based on the nutritional value of the substances contained in the lake (trophicity), three types of lakes are distinguished:

• Oligotrophic (with a small amount of nutrients) - lakes are usually characterized by large or medium depths, a significant mass of water below the temperature jump layer, high transparency, water color from blue to green, a gradual drop in O2 content to the bottom, near which the water always contains significant amounts of O2 (at least 60% of its content on the surface)
• Eutrophic (with a high content of nutrients) - well-warmed lakes (the layer below the temperature jump is very small), transparency is low, the color of the water is from green to brown, the bottom is covered with organic silt. The water is rich in nutritious salts, the O2 content drops sharply towards the bottom, where it often disappears completely.
• Dystrophic (poor in nutrients) - swampy lakes with low transparency and yellow or brown (due to the high content of humic substances) water color. The mineralization of water is low, the O2 content is low due to its consumption for the oxidation of organic substances.

In modern hydrology and hydroecology, intermediate levels of trophic classification are distinguished: mesotrophic (between oligotrophic and eutrophic) and hypertrophic.

According to their location on celestial bodies, lakes are divided into:

• earthly;
• extraterrestrial.

The largest lakes on Earth

The total area of ​​the world's lakes is about 1.8% of the land (approximately 2.7 million km²).

Lake name	Maximum surface area, thousand km²	Altitude above sea level, m	Maximum depth, m	Part of the world
Caspian Sea
Upper				North America
Victoria
Huron				North America
Michigan				North America (USA)
Tanganyika
Baikal				Asia (Russia)
Malawi
Big Bear
Great Slave				North America (Canada)
Erie
Chad
Winnipeg				North America (Canada)
Balkhash				Asia (Kazakhstan)
Ontario				North America
Aral Sea
Ladoga				Europe (Russia)