What rivers and lakes are there? Lake Peipsi - the grandeur of the dunes

Fresh water is Russia's main wealth. This is something our children and grandchildren should be proud of. It is in the Russian Federation that the largest number of people in the world are located clean water. Below is a ranking of the ten largest Russian lakes by area, which are considered among the cleanest and deepest in the world. Well, are you ready? Let's go...

Lake Ilmen is located in the Novgorod region. Its area is 982 sq. km. The greatest depth is up to 10 meters.

This lake has a very winding coastline. Its area is 986 sq. km. The maximum depth is up to 56 meters. This place is very popular with kayakers and fishermen.

White Lake is located in the Vologda region. Its area is approximately 1284 sq. km. The average depth is 5–7 m. Approximately 29 species of different fish live here.

Lake Chany is located in the Novosibirsk region. Its water is salty. The area varies according to various estimates. from 1400 to 2000 sq. km. The greatest depth is 7 m. According to ancient legends, a huge snake lives in this lake, which devours people and livestock.

Lake Khanka is located on Far East Russia. Its maximum depth is about 11 m, area - 4,070 sq. km.

Lake Taimyr is located on the peninsula of the same name in the Krasnoyarsk Territory and is considered the northernmost in the world. Almost always covered with ice. Due to fluctuations in water level, its area can change and reach 4,560 sq. km. Max. depth - up to 26 m.

Lake Onega is located on the territory of Karelia, Leningrad and Vologda regions. Its Area is approx. 9,700 sq. km. The greatest depth is 127 m.

Lake Ladoga is located in Karelia and Leningrad region. It is the largest freshwater lake in Europe. Its area is more than 17.6 thousand sq. km. The maximum depth is 230 meters. 35 rivers flow into it.

Posted Mon, 15/08/2016 - 08:53 by Cap

Etymology

In early Russian written monuments, the origin of the name is unknown. Probably the ancient, Dauphinian origin of the name of the lake.

There are several versions of the origin of the name:
Academician A. M. Sjögren derives the name of the lake from the Finnish. ääni - sound, voice, hence - “sounding (noisy) lake.”
A.L. Pogodin deciphers this toponym from the Sami. agne - “sand” + jegge - “low-lying plain”.
Professor, Doctor of Philology I. I. Mullonen believes that the name of the lake could have come from the Sami. äne and Baltic-Finnish änine/äniz, which means “large, significant”.

The main beach of Novgorod is located on the banks of the Volkhov, right next to the walls of the Kremlin. However, in hot weather it is packed to capacity, and it would seem that relaxing on Ilmen is more pleasant than in the city. However, the lake shores are low, often swampy, overgrown with reeds and indented by channels, so there are few beaches in the usual sense on Ilmen. All places suitable for swimming can be recognized by the quality of dachas and country houses - real estate in “resort” areas is expensive. Good sandy beach is located near the Perynsky monastery, a good one is near the villages of Ondvor and Ilmen, as well as near Sergovo. They are all wild, i.e. unfurnished. Their cleanliness depends only on the environmental consciousness of vacationers, which still leaves much to be desired. On south coast lakes, 30 km from Staraya Russa, there is a popular place Korostyn with a pebble beach.

Another name is Ostashkovskoye, after the name of the city of Ostashkov, located on the lake shore.
The area of ​​the lake is 260 km², including about 38 km² of islands (there are more than 160 of them on Seliger). The largest is Khachin.
The area of ​​the entire basin is 2275 km².

Maximum depth: 55 m
Area: 300 hectares
Altitude: 1790 m
Administrative region: Ust-Koksinsky
Tourist area: Katunskie squirrels

Its name comes from the Altai tribe of Teleuts, and in Altai it is called Altyn-Kol, which means " golden lake"According to an old legend, in ancient times there was a famine in Altai. One Altai man had a large gold bar, but, having walked all over Altai, he could not buy anything with it. Frustrated and hungry, the “rich” poor man threw his bar into the lake and He himself died in its waves. Since then, in the Altai language the lake is called Altyn-Kol - “golden lake”.

Translated from Bashkir, the name of the lake means “Beaver Lake”. Beavers lived here before, but now you won’t see them here anymore.

There is another version: but according to legend, on the northern shore, on the red sandy mountain from which stones fall into the lake, there used to be a khan’s headquarters.

Over time, the area began to be called “Khan-tora”, “Khan-torganer”, the place where the khan lives gradually began to be called Kandra.

The food is mixed, snow, underground and rain.

The water in the lake is slightly brackish with high mineralization.

The vegetation is represented by reeds, cattails and common reeds.

Lake Asylykul was formed, as many researchers claim, on the site of a giant karst sinkhole, gradually filled with water due to precipitation and groundwater. This happened, according to scientists, a million years ago.

In strong windy weather it resembles the sea: huge waves They float ashore, creating truly the sound of the sea surf. The southern coast is a rather steep slope with a height difference from 210 to 370 meters. The eastern side of this slope is covered with mixed forest, the middle part is covered with young larch and pine plantations.

ORIGIN OF THE NAME OF THE LAKE

There are several translation options for the name of the lake - “bitter lake”, “collapsed lake”, “bright lake”.

The presence of the word “bitter” in one of the interpretations of the name is explained by the salinity of the lake due to the high mineralization of the water due to the drainage of the lake. A kind of small sea in the center of Bashkiria.

first ice on Lake Galich


The water level in the lake is 100 m above sea level. Lake Galich is fed mainly by groundwater. From the eastern side several rivers flow into it, the largest are Chelsma and Serednaya, and Vyoksa flows out.
On the southern shore of the lake is the city of Galich.
The lake is rich in fish, but in recent years there has been a tendency for it to become shallower. Due to the shallowness of the water, 70% of the reservoir's area is overgrown with thickets and silt, which can threaten the lake's ecosystem.

SALT LAKE CAMPAIGN

Camber - small salt lake artificial origin, located on the southern outskirts of the city of Sol-Iletsk Orenburg region. Lake Razval is the largest of the group of Iletsk lakes: Tuzluchnoe, Teploye, Dunino, Novoe, Maloe and Bolshoye Gorodskoe lakes.
In the middle of the 18th century (1754), the industrial development of the Iletsk salt dome began in the Sol-Iletsk district of the Orenburg region. At the point where the salt core emerged on the day surface, Mount Tuz-Tyube rose. TO end of the 19th century century, in place of the mountain a hollow appeared, up to 35 meters deep, 300 meters long, 240 meters wide. In April 1906, as a result of the flooding of the basin by the flood waters of the Peschanka River, Lake Razval was formed with an area of ​​6.8 hectares with maximum depths of up to 22 meters.
The water in Lake Sol-Iletsk is a saturated saline solution containing more than 200 grams of salt per liter of water.
Lake Razval does not freeze even in the most severe frosts, and from a depth of 2-3 meters to the bottom it has negative temperatures all year round. In terms of the chemical composition and salt concentration, the water in Lake Sol-Iletsk is similar to the water in the Dead Sea. There are no living organisms or vegetation in the lake. No household waste is dumped into Razval, so the lake is environmentally friendly.
Due to the high salinity, the water in the lake has a higher density than the human body, and therefore it is impossible to go to the bottom while swimming. Since 2002, the lake has been surrounded by a lattice-metal fence.
There are several restaurants and a beach disco here. People from various countries come to the lake, mainly Russia and Kazakhstan.

Lake Tuzluchnoe (mud)
It is the oldest of all the surviving lakes of the Sol-Iletsk salt dome.
The area of ​​the lake is 23,750 sq. m., depth 2.5 meters, thickness of the mud layer up to 2 meters or more. The most active part of the mud is the colloidal complex.
It contains iron sulfide, silicic acid, and tiny clay particles. Hormones and biogenic stimulants - substances make up the most valuable part of the mud. A course of treatment with mud helps to resolve scars, improve joint function, scar ulcers, relieve chronic pain syndromes, normalize the function of the reproductive system, and treat the female genital area.

Lake Dunino (bromine, formed in 1896)
Formed in 1896. It is located 50 meters east of Lake Razval
The area of ​​the lake is 88,550 sq.m. , depth 13 meters. It contains more than 20 thousand cubic meters of healing mud and a lot of bromine.
Swimming in this lake is recommended for people with increased irritability, nervous breakdowns, as well as patients with initial manifestations of hypertension, stomach ulcers, and skin diseases.
In the lake, crustaceans and salted brine shrimp multiply in large numbers, which give the lake a unique color. One liter of water contains 165.5 grams of various salts.

It is located 40 km west of the city of Chita. (right tributary of the Selenga).
The water surface area is 58.5 km², the catchment area is 256 km², the volume of water is 0.610 km³.

Length - 10.9 km, greatest width - 6.8 km. Height above sea level - 965.1 m.
The water in the lake is fresh and running. Mineralization - 100-200 mg/dm³.
Lake Arakhlei differs from other Ivano-Arakhlei lakes in its significant depths - the greatest depth is 19.5 m in the northeastern part of the reservoir.
In the central part, depths reach more than 16 m. A rapid increase in depths can be observed in the northern part of the lake. In the southern part the bottom is flat with a gradual increase in depth towards the center of the lake.

Lake Arakhlei
In the coastal part the bottom is sandy and pebble, down to a depth of 3-5 meters it is sandy and silty. The rest of the bottom is covered with organic silt.
Two small rivers flow into the lake - Domka and Gryaznukha (Shaborta).
In high-water years, the Kholoi stream flows out of the lake and flows into Lake Shakshinskoye ().
On the shores of the lake there are the villages of Arakhlei, Preobrazhenka and various recreation centers.

(Beklemishevskie lakes, Chita lakes) - a system of lakes.
It is located at an altitude of 945-965 meters above sea level in the basin between the Osinov and Yablonov ridges west of Chita.
It consists of 6 large lakes with a water surface of more than 10 km² (Arakhlei, Shakshinskoye, Irgen, Ivan, Tasey, Bolshoi Undugun) and approximately 20 small reservoirs with an area of ​​less than 1 km².
Ivan and Tasei belong to the Lena basin, and Arakhlei, Shakshinskoye, Bolshoi Undugun and Irgen belong to the Baikal basin.
The lakes are the center of the protected area of ​​the Ivano-Arakhleisky reserve.

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SOURCE OF INFORMATION AND PHOTO:
Team Nomads
Geography of the USSR.
http://gruzdoff.ru/
Wikipedia website.
http://ucrazy.ru/
http://geographyofrussia.com/
Waterfalls of Russia.

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Caspian Sea- lake, the largest in the world in terms of area and volume of water. Its waters wash the shores of five states, including southern Russia. . The salinity of most of the sea-lake is approximately three times less than that of the ocean; in the northern part (the coast of Russia), the water in the lake is almost fresh. In this part of it, the lake is rich in fish, especially sturgeon: a total of 101 species of fish, as well as many freshwater fish - such as roach, carp, pike perch. The lake is the breadwinner!

The length of the coastline of the Caspian Sea is estimated at approximately 6500 - 6700 kilometers, with islands - up to 7000 kilometers.

130 rivers flow into the Caspian Sea, nine of them have a delta-shaped mouth. The largest rivers flowing into the Caspian Sea: Volga, Terek (Russia), Ural, Emba (Kazakhstan), Kura (Azerbaijan), Samur (Russian border with Azerbaijan), Atrek (Turkmenistan)

The most important dangers for the Caspian Sea are associated with water pollution as a result of oil production and transportation on the continental shelf, the flow of pollutants from the Volga and other rivers flowing into the Caspian Sea, the life of coastal cities, as well as the flooding of individual objects due to rising levels of the Caspian Sea .

Famous Lake Baikal- the biggest freshwater lake Eurasia. The most deep lake in the world its depth is 1642 meters.

The water reserves in Baikal are simply gigantic - 23,615.39 km³ (about 19% of the world's lake fresh water reserves - all fresh lakes in the world contain 123 thousand km³ of water). In terms of water reserves, Baikal is second only to the Caspian Sea.

336 rivers and streams flow into Baikal

In winter, the surface of Lake Baikal freezes almost completely; there is only a small section 15-20 km long, located at the source of the Angara.

Lake Baikal is home to 2,630 species and varieties of plants and animals

Ladoga And Lake Onega - the largest in Europe.

Large rivers carry their waters into Lake Ladoga: Svir, Vuoksa and Volkhov, several dozen medium-sized rivers and more than a hundred small ones. Only one flows out of the lake - the Neva.

Lake Ladoga has an abundance of islands, the number of which exceeds 650

Lake Onega is one of the largest freshwater bodies of water in Europe. Its area is about 10,000 square kilometers, length up to 248 kilometers, width up to 80 kilometers. The average depth of the lake is 30 meters.

The lake is famous for its huge number of islands, especially in the northern part. Their total number reaches 1369

Lake Elton

Lake Elton is one of the most interesting natural sites in the territory Volgograd region. A salt lake of enormous size, comparable only to the Israeli one Dead Sea, located in the middle of the Pallasovskaya steppe.

Lake Elton appears to be the largest and richest of all known salt lakes in the world. The thickness of the salt layer has not yet been precisely determined. But the most important thing about Elton is its healing properties. Once upon a time there was even a Museum of Abandoned Crutches: people who came here on crutches returned home after a month or two, leaving their crutches in a local sanatorium

It has long been noticed that by the end of summer the surface of the lake turns a mysterious purple-golden color.

Lotus Lake

In Russia, lotuses grow in only two places - in Astrakhan region and in the Far East. Lotus Lake (or Goose Lake) is a unique body of water, covered with a carpet of rare pink flowers all summer. This lake is located on one of the most picturesque islands Peter the Great Bay

A wonderful legend is told about the lake. As if there used to be a valley in its place where the village was located. There was a well in the middle of the village. One day, water began to flow from this well, which flooded the village. It is believed that the waters of Lake Baikal broke through, with which Gusinoye is connected by a huge underground canal. They say that even wrecks of ships that sank in Lake Baikal are found here. And the endemic omul is also found in Lotus Lake.

The most beautiful and amazing lakes, isn't it?

- 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: basin, water mass, vegetation and fauna 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 They are distinguished by their large sizes, and most have significant depths and steep rocky slopes. The bottom of many deep lakes lie below the level of the World Ocean, and the mirror oxen 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.

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 owe their origin to the destructive activity of ancient glaciers, which are elongated in the direction of glacier movement from northwest to southeast along tectonic cracks. 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

Depending from water balance, t.s. According to the conditions of inflow and outflow, lakes are divided into drainage and drainage. 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 changes climate. 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.

In the distribution of lakes with varying degrees of mineralization on the earth's surface, geographic zonality can be traced, 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 are generally 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, there is a “blooming” of water 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, and a decrease in inflow river waters, 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 salt concentration increases, and even fresh lake may turn first into a salt lake (Great 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.

The most big 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 closed 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 runs along the line Chechen (island) - Tyub-Karagansky Cape, between the Middle and Southern Caspian - along the line Zhilaya (island) - Gan-Gulu (cape). The area of ​​the Northern, Middle and Southern Caspian is respectively 25, 36, 39 percent of total area 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.

On east coast Limestone coasts predominate, adjacent to semi-deserts and deserts. The most winding shores are on the west coast in the area Absheron Peninsula and on the east 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.

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

Rounding out the top three 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 north coast Kampala, capital of Uganda.

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 the lake Michigan, connected to it by the Straits 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 Indian tribe Huron. Manitoulin is located on Huron - the most big island world, located in a fresh lake.

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 Lake Superior, 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. Major 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.

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 kill or retard the development of natural vegetation and crops. 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 raises concerns that deadly microorganisms remain viable, and infected rodents could 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 Aral Sea complete disappearance by 2020...

Lake Tanganyika — 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 - Democratic Republic 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 side walls of the East African Rift Zone that form the coastline reach 2000 m in height. Coastline 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 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 ended with the development large quantity 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.