Holy Lake can be described as beautiful. Characteristics of the lake: origin of lake basins and types of lakes. Types of lakes by origin

Music for happiness - gentle guitar

The first chord is light, a breath of wind, your fingers barely touch the strings. A vanishingly quiet sound, E minor, simpler and there is nothing...
The first snowflake is light, translucent, carried by an almost imperceptible wind. She is the harbinger of snowfall, a scout who was the first to descend to the ground...

The second chord – the fingers of the left hand are deftly rearranged, the right one confidently and softly leads along the strings. Down, down, up - simple and gives the simplest sound. It's not a blizzard or a storm - just snowfall. There can be nothing complicated about it. Snowflakes begin to fly more often - the vanguard of the main forces, sparkling ice stars.

Then the chords replace each other more viscously and tenderly, so that the ear almost does not notice the transition from one sound to another. A transition that always sounds harsh. Instead of a fight, it’s too much. Eight. The intro is played and even if it’s not an instrumental that sounds triumphant and joyful during a summer downpour or viscous and bewitching in a snowstorm, even if it’s just chords put together, the music surprisingly suits the snow outside the window, the white butterflies of winter, the icy tiny stars that are all dancing, dancing their dance in the night sky...

Singing is woven into the music - quiet, the words are indistinguishable, elude perception, mixed with the snowfall and the measured, natural beating of the heart. A clear rhythm and calm strength resound in them. The song has no end, it just softly intertwines with the dance of snowflakes and goes away imperceptibly, leaving the sky and snow alone...
Cold and darkness conceal sounds and movements, reconciling the city with winter...

And the Lord of Snowfall, having played his part on one of the roofs, gently puts his guitar, which has power over the elements, into its case. There is snow on his shoulders and hair, red cheerful sparks flash and go out - snowflakes reflect the light of distant lights. There is light in the windows of the house opposite. There are people there who don’t know how to weave the lace of the elements...

The staircase is an ordinary staircase of a nine-story building. Doors, an elevator always occupied by someone, the dim light of a light bulb on the landing... The Lord of Snowfall walks, holding his guitar, quietly and slowly walking up the steps. From the ninth floor to the first, carefully so as not to disturb the warm feeling of relaxed, trusting happiness that comes every time after completing the game...
And the usual angry question from the mother who opened the door:
– When will you stop playing your games and finally start thinking?
It hits the open soul like a knife. The soft snow wings given by the fulfillment of the present break and only misunderstanding and resentment remain.
Why does she hit where it hurts the most? For what?..

At night, a wild wind mixed with snow blew through the city. Broke tree branches, tore wires, swept roads...
It was the Lord of Snowfall's guitar singing again.

Geographical objects are everything that surrounds us, that is, they are stable or relatively stable objects with a certain location on Earth that can be described. Our article will tell you how to describe a lake.

Standard plan for describing geographical objects

Before making a plan for describing a lake, you should briefly make a plan for a story about any geographical feature. So, we can describe it:

• population in a certain territory;
• journey;
• natural resources of the country;
• geographical location of the continent;
• relief of the territory;
• climate;
• natural area/areas;
• country;
• Agriculture;
• description of the political map.

As can be seen from the list above, anything can be described and each object has its own plan. But if you don’t know it, then you can describe the object according to a standard plan, which is the following:

Lake description plan: where to start

As mentioned above, there are standard types of description, and each object has its own plan, including a water body such as a lake. First you need to make a brief plan, and then describe it in more detail.

Lake description plan:

In this plan for describing the lake, you can also add a division of salt lakes according to their chemical composition, which are divided into carbonate, sulfate and chloride. Lakes can also be divided according to nutrients:

• oligotrophic, i.e. low amount of nutrients;
• eutrophic, i.e. where there is a large amount of nutrients;
• dystrophic, i.e. poor in nutrients, mainly refers to swampy lakes.

Plan for describing basic information

The description of lakes can be done following the plan described above. It is universal and suitable for characterizing any body of water. But first, it’s worth giving a definition.

A lake is a naturally occurring body of water that is filled with water within the lake bowl and has no connection with the sea or ocean.

On planet Earth today there are more than 40 largest lakes, which have an area of ​​more than 4 thousand km2. The largest are the Caspian Sea, Huron, Victoria, Superior and Michigan.

The description of the lake should begin with its name. For example, this is where the story of Lake Huron can begin. It is located in North America in two countries: Canada and the USA. It occupies an area of ​​59 thousand 600 kilometers and has a depth of up to 229 meters.

Next, it is necessary to determine the type of basin, which are divided by origin into tectonic (i.e., formed in places of a fault or shift in the earth's crust); glacial (when the basin was formed by plowing a glacier); river; seaside; failures (formed where frozen soils began to thaw); underground; volcanic; artificial.

It should be clarified that Lake Huron is freshwater and was formed due to tectonic processes.

Other lakes should be described according to the same plan, for example, the largest in Russia and one of the largest among freshwater lakes - Lake Baikal. Let's look at a few examples.

Lake Baikal

It is worth starting the description of Lake Baikal according to the plan with its location. It is located in Central Asia, in Irkutsk region Russia. This is one of the largest lakes in the world, which ranks seventh in area and is the deepest among freshwater lakes. Its depth is 1637 meters.

Lake of tectonic origin. Scientists are still arguing about its origin, since they cannot fully establish the exact date. It stretches for 600 kilometers, and in some places its width can reach 80 kilometers. The area of ​​the reservoir is 31 thousand km2, the same as, for example, the area of ​​Belgium or Denmark. The coastline stretches for 2,100 kilometers, in the west the coast is rocky and steep, and in the east it is flatter.

Lake Baikal is a drainage lake, more than 300 rivers and streams flow into it, the largest are Snezhnaya, Barguzin, Sarma, and only the Angara River flows out.

The description of Lake Baikal according to the plan can be completed by clarifying the volume of water. They are huge, and account for 19% of all fresh water reserves, second only to the Caspian Sea. The lake is home to more than 2 thousand species of plants and animals, 2/3 of which are endemic, that is, living organisms that are found only in this reservoir. This abundance is explained by the high oxygen content throughout the water column.

Lake Victoria

The plan for describing Lake Victoria should begin with the fact that it is located in East Africa on the territory of three states, such as Kenya, Uganda and Tanzania. In terms of area, it ranks first on the mainland and third in the whole world and is 68 thousand km2, the maximum depth is 80 meters, and the length coastline stretches for 7 thousand kilometers.

The lake is a drainage lake, the Kagera River flows into it, and the Victoria and Nile flow out, but the main source of nutrition is precipitation, and not its tributaries.

The shores of the lake are mostly flat and low, heavily indented and swampy.

Lake Victoria is one of the largest freshwater lakes, which ranks third in area. It is home to more than 200 species of fish, on which many animals feed.

Lake Chad

The plan for describing Lake Chad needs to start with the fact that it is located in Central Africa on the territory of several states, more precisely the Republic of Chad, Nigeria, Niger and Cameroon.

The lake is in twelfth position among the largest lakes in the whole world and covers an area of ​​26 thousand km2. It is impossible to clearly indicate the area, because during rains it floods and the area increases to 50 thousand km2, and during drought the area decreases to 11 thousand km2. The maximum depth reaches 12 meters.

In the south, the Shari River, which is one of the food sources, flows into the lake, in the west the Komadugu-Vaube River, in the east Bar el-Ghazali.

Lake Superior is the name given by the pioneers to the largest lake on the North American continent.

This body of water is the northernmost of the Great Lakes, ranks second in the world ranking in terms of area and third in terms of fresh water reserves.

Lake Superior is one of the most beautiful natural attractions in the United States and Canada.

Great Lakes

A description of Lake Superior must begin with a description of the Great Lakes system. This is the name given to an extended and powerful chain of reservoirs located in the northern part of North America.

The huge chain consists of lakes such as Huron, Michigan, Ontario, Erie, Superior and smaller water bodies. Michigan belongs exclusively to the United States of America. The shorelines of the other four largest of the Great Lakes cross the US-Canadian border in one way or another. Lake Superior on the North American mainland is also no exception; it is also located on the border of two states.

The Great Lakes are an important part of the transport network of the two countries, as well as a place of pilgrimage for a huge number of tourists, primarily, of course, American and Canadian, because famous natural parks are located here. In addition to its critical importance in the modern economy, the Great Lakes played a large role in the history of the United States, in particular, it was here that the famous naval battles between the Americans and the British took place.

The original name of this gigantic body of water has survived to this day. Indians from the Ojibwe tribe, who inhabited the shores of the lake before the arrival of Europeans, gave it the name “Geechi Gami”, which can be translated as “ big water" This historical name suits this impressively sized body of water perfectly.

Lake Superior is the largest of the Great Lakes system. In its longest part it reaches 616 meters, and in its widest part - 257 meters. The area of ​​Lake Superior is huge, it is approximately 82.4 thousand square kilometers of water surface. This fact makes it the second largest area on the entire planet after the Caspian Sea, which is now considered a lake.

Lake Superior has a total volume of more than 11.5 thousand cubic kilometers (the maximum volume is more than 12 thousand cubic kilometers). This allows hydrologists to say that the reservoir contains a tenth of the world's fresh water reserves (the third largest in the world after our Baikal and Tanganyika in Africa). To imagine how huge this figure is, we can cite the following fact: if you distribute all the water in Verkhniy, spilling it over a huge plane, the area of ​​which is equal to North and South America, you will get a layer of water of 0.3 meters. The volume of water in this reservoir exceeds the total volume of all other Great Lakes combined.

The Upper Lake, despite its name, does not belong to the alpine category. It is located at an altitude of only 183.5 meters above sea level.

Lake Superior is also outside the deepest category. In terms of its depth, the reservoir claims only 36th place in the world ranking. Its average depth is 147 km, and its maximum depth is 406 meters. For comparison, the depth of Baikal is 1642 meters.

On the shores of the lake there is the Canadian province of Ontario on one side, and the American states of Michigan, Minnesota and Wisconsin on the other. The coastline of Lake Superior stretches for more than 4,000 kilometers.

Hydrological regime

More than two hundred rivers and streams carry their waters into the lake. Among the largest are the Pigeon River, Nipigon, Peak, St. Louis, White and many others.

From Superior flows the large St. Marys River, which feeds Huron, the second of the Great Lakes chain.

Despite the fact that the average annual water temperature in Verkhny is 4 degrees above zero, due to the great depth and strong and frequent waves (strong storms often occur here in autumn and winter), the water surface almost never freezes completely. The last case of complete freezing was noted in the 70s of the twentieth century. The rest of the time, only the coastal strip of water is covered with an ice crust. The period of coastal ice lasts from December to April.

Geographical position Lake Superior contributes to moderate fluctuations in water levels. The maximum level occurs in the summer months during periods of heavy rainfall, and the minimum level occurs in the winter months.

Geological history

Verkhneye is a relatively young American lake by geological standards. It was formed approximately 4-10 thousand years ago during the Ice Age. A powerful glacier, which at that time covered quite large areas North American continent, managed to push through the rocks of the stable Canadian Shield, thus forming a powerful and extensive recess in the earth's surface. According to geologists, the glacier subsequently melted, giving rise to a gigantic reservoir with its melt waters, which spread over the entire area where all the Great American Lakes now lie. The impressively sized reservoir gradually shrank, and the contours of the modern lake chain began to appear, including the shoreline of Lake Superior.

Islands

The largest of the upper lake islands is Isle Royale. It lives up to its “royal” name and reaches a length of 72 and a width of 14 kilometers. An interesting fact is that this island is often called “matryoshka”.

Why, you ask? It's simple: there are quite a lot of large lake, which also has an island. On this relatively small island there is a small pond on which smaller islands are scattered. Such a bizarre natural “architecture”.

Attractions

Important attractions of the Lake Superior region include specially protected natural areas. They include the famous American Isle Royale National Park, located on the island of the same name, and the no less famous Canadian Pukaskwa National Park. Tourists and travel enthusiasts come here, because the lake, despite the fact that it has long been discovered by man, has retained its pristine beauty and comparative purity of water. Since in Lake Superior There are valuable species of fish, this indicates the good ecological condition of the area.

Shipping

The largest and most important ports on the lake are the American ports of Ashland and Duluth, as well as the Canadian port of Thunder Bay.

The Verkhny region is the most important navigable territory for the two states.

Since the lake is characterized by a violent and restless temperament, severe storms and storms, it was wrecked great amount ships.

Cape White Fish, which is sometimes called the “tomb,” became especially notorious in this regard. It was here that many ships sank for certain reasons.

• Locals they claim that the lake is very reluctant to give up its drowned people, who almost never float to the surface. Apparently, this is due to the extremely low temperature of the water and the low content of microorganisms in it.
• Verkhny is home to several dozen valuable species of ichthyofauna, many of which are caught industrially (including sturgeon, smelt, salmon, trout, carp, whitefish, freshwater herring, pike perch and others). At the beginning of the 17th century, Europeans who visited here reported almost three-meter sturgeon and two-meter pike.
• About sixty species of orchids grow in the lake area.

- 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 They are distinguished by their large sizes, 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.

Volcanic lakes occupy craters and calderas 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, primary sea water can be greatly transformed and even completely displaced and replaced by atmospheric waters (Ladozhskoye, 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 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 and 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 composition 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 in the hot thermal zone are characterized by the warmest water at the surface, which 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. Katabatic 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 large, deep, transparent 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 raft, 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.