- Name the most large lakes Russia.
- Which lakes in our country have basins of the same origin as the largest lakes in Africa; North America?
- Remember the main reasons for the formation of swamps.
- How are formed The groundwater?
Lakes... There are a little less than three million lakes in our country. Among the lakes of Russia, the largest sea-lake in the world is the Caspian and the deepest (1637 m) freshwater lake Baikal.
Table 4. The largest lakes in Russia
The distribution of lakes throughout the country is very uneven and depends on many reasons: geological structure and terrain, climatic conditions, occurrence features groundwater.
By climate maps determine in which part of our country the conditions for the existence of lakes are the most favorable.
The number of lakes decreases significantly to the south due to the increasing aridity of the climate.
The origin of the lake basins is diverse (Table 5).
Lakes are springs fresh water, food products, raw materials (for example, salt in lakes Elton and Baskunchak), flow regulators, navigable routes, wonderful places of rest.
Unlike rivers, lakes are reservoirs with calm water, but they also actively influence other components of nature. Lakes change the relief: they create the bottom and shores, cliffs and terraces, overwhelm their basins with peat, silt, salt, turning them into swampy plains, salt marshes and even salt deposits. Lakes influence the climate: in summer they moderate the heat, in winter they soften the cold; moisten the windward shores with moisture evaporating from their surface.
Table 5. Origin of lake basins in our country
Think, in which areas of our country, instead of lakes, swampy plains can form; salt marshes.
Reservoirs, which are created on rivers by the construction of dams, have become a new type of lakes. But in addition to the benefits of reservoirs, they can negatively affect nature: destroy the banks, raise flooded peat bogs from the bottom, cut roads, flood and flood forests and agricultural land.
Swamps... The area of bogs in Russia is about 2 million km2, that is, over 10% of the entire territory.
Reasons for the emergence of swamps: waterlogging of the soil with a large amount of precipitation, low evaporation and slow runoff. The evolution of small lakes also ends with the formation of bogs. The Northwest of the Russian Plain (up to 20-30%), Vasyugane in the West Siberian Plain (up to 70%), and the Amur basin (10-12%) are heavily bogged.
Remember how the swamps are depicted on the map. Find the main swamp areas.
Bogs are an important source of nutrition for rivers and lakes, and many useful berries: cranberries, cloudberries. Therefore, the conservation of wetlands is important for the protection and rational use the wealth of nature.
Diverse and practical use swamps. About 80% of the country's peat reserves are concentrated in the swamps of the forest zone, which is used for thermal power plants and as a raw material for the chemical industry.
The groundwater although hidden from view, their role is great both in nature and in human life. These waters make their way at the bottom of the rivers with cold springs, come to the surface as ice springs. Extracted from wells or wells, these waters are used for domestic needs, irrigation of fields, watering of pastures.
Groundwater has different origins: some of them were formed as a result of the penetration of melt and rainwater to the first water-resistant horizon (that is, to a depth of 1.5-2.0 m - this is the so-called top water); others occupy deeper cavities in the ground.
Rice. 49. Transition of surface runoff into underground
Groundwater is fresh and mineral, containing quite large quantities of soluble salts and gases. Mineral waters are used in medicinal purposes... In different regions of the country - in Kamchatka, the Caucasus and elsewhere - reserves of thermal groundwater with temperatures ranging from 30 to 300 ° C have been identified.
Groundwater reserves in our country are estimated in many trillion cubic meters, of which 350 billion are considered suitable for use. However, only a small fraction of these reserves is still used - about 5%. But even such reserves are not unlimited. They, no less than ground waters, need protection, careful use, protection from pollution.
Glaciers currently occupy about 11% of the land; underground ice (permafrost) is spread over 14% of the Earth's land mass. In Russia, permafrost occupies 11.1 million km 2, that is, more than half of the entire territory.
Glaciers have a noticeable impact on nature: they are stores of moisture, they own important role in the feeding of rivers, they noticeably change the relief. Large covers land ice, similar to the Antarctic and Greenlandic, we do not have, but smaller ice sheets ("island" caps) are found on the Arctic islands. Mountain glaciers are common in the Caucasus, Northern Urals, Altai, Eastern Siberia, Sayan Mountains, Transbaikalia and Kamchatka. Their total area about 3 thousand km 2.
In the highlands there is the so-called snow border, above which the snow falling during the cold season does not have time to melt and persists until next winter and then turns to ice.
V southern mountains the snow border lies higher than in the northern ones, and in the Arctic it goes down to sea level. Its height depends on the severity and humidity of the climate. On the well-moistened slopes of the Western Caucasus, this boundary can be traced at altitudes of 2700-2800 m, and on the drier slopes of the Eastern Caucasus - at altitudes of 3000-3200 m. In the Caucasus, there are up to 1400 glaciers; in Altai - 754, in the mountains of Eastern Siberia - 200 glaciers.
Permafrost - these are the strata rocks containing ice that does not thaw for a long time, usually tens or many hundreds of years. Permafrost occupies the coast of the Northern Arctic Ocean in the European part of Russia, including the entire Kola Peninsula; Siberia is practically all (except for the south Western Siberia and Far Eastern Primorye) lies within its boundaries. Thus, more than 60% of the area of Russia is, to one degree or another, occupied by permafrost. In areas with the most severe climate - at the mouth of the Vilyui, in Oymyakon, where the sum of average daily negative temperatures reaches 6000-7000 ° C - the thickness of the permafrost layer is on average 600-800 m, and in some places it reaches 1500 m.
Permafrost has a significant impact on nature, as well as on human life and activities.
Rice. 50. State of permafrost during the year
Permafrost is a "refrigerator" for soil and surface air; it limits the depth of root penetration into the ground and their water supply. Waters accumulating on the permafrost swamp the area, leading to the formation of subsidence, flooding and swelling of the surface. Permafrost complicates the construction of roads, buildings, and mining. Our country has accumulated extensive experience in construction and economic activity in permafrost conditions. It was used in the construction of new cities - Norilsk, Mirny, in the construction of the BAM.
Questions and tasks
- What types of lake basins are there in our country? Is there a pattern in their placement?
- Think about what contributes to the formation of swamps; where there are especially many large swamps in our country. What is the role of swamps in nature?
- How important is groundwater for human life?
- In what areas are glaciers concentrated? Why?
- What are the reasons for the formation of permafrost. How does it affect nature, life and human activity?
Lakes, groundwater, permafrost and glaciers are wealth water resources, a variety of landscapes.
Tasks when studying the topic:
Formation of understanding that any object of inland waters (river, lake, etc.) is a complex natural system that requires deep study and knowledge for economic use and requiring protection and rational use.
Requirements for the preparation of students:
Give examples of the importance of different types of inland waters as water resources. Show on the map large lakes, areas of permafrost, glaciers. Explain the location of inland waters throughout the country.
Goals and objectives of the lesson:
- To form knowledge about lakes, swamps, groundwater, glaciers, snow cover, permafrost, their characteristics, location, significance in nature and in human life.
- To give an idea of the location, features, origin, significance of lakes, swamps, groundwater, glaciers, permafrost.
- Continue learning to work with maps, tables and other sources of information.
Equipment: Physical map of Russia, soil map (with permafrost boundary), tables: lakes, groundwater, glaciers. Presentations "Museum of Permafrost", "The Amazing World of Swamps".
During the classes
I. Organizational moment.
II. Repetition. Homework check.
Option I.
1. Most of the rivers in Russia are fed:
a) rain;
b) glacial;
c) snow;
d) mixed.
2. Erosion of rocks, soils by flowing water is called:
a) accumulation;
b) erosion;
c) the fall of the river.
a) Yenisei;
4. Border rivers are:
c) Yenisei;
d) Ussuri.
5. Sudden rise in the water level in the river:
a) flood;
b) flood;
c) flood.
6. Funnel-shaped mouth of the river, widening towards the sea:
a) estuary;
b) delta.
7. Rivers of the Pacific Ocean basin:
a) Ussuri;
b) Anadyr;
c) Kolyma;
8. Rivers of the internal drainage basin:
d) Northern Dvina.
9. The most widely used water for economic purposes:
c) underground;
d) glaciers.
10. The mountain river is:
c) Pechora;
11. Most of the rivers in Russia have a mixed diet with a predominance of:
a) rain;
b) snow;
c) underground;
d) glacial.
Test of knowledge of the map: show the rivers of the basins of the Arctic, Atlantic oceans.
Rivers of the Arctic Ocean basin: North. Dvina, Onega, Pechora, Ob with Irtysh, Yenisei with Angara, Lena with Vilyuy and Aldan, Yana, Indigirka, Kolyma. Basin rivers Atlantic Ocean- Neva (flows out of Lake Ladoga and flows into the Gulf of Finland Baltic Sea... Dnieper, Don, Kuban).
Frontal work.
Repeat terms: river system, source, mouth, basin, river fall, river slope, water discharge, annual flow, river regime, solid flow, flood, flood.
III. Learning new material
Lakes are closed basins filled with water.
Salts accumulate in such a lake.
1) The deepest lakes are of tectonic origin(in faults, cracks in the earth's crust). Such lakes are oblong: narrow and long. This origin has the most deep lake the world - Baikal (1637 m).
Lakes of glacial-tectonic origin (tectonic depressions were deepened under the weight of an ancient glacier) are located in the northwest of the Russian Plain. The largest of them are Ladoga, Onega, Imandra.
Moraine lakes occupy depressions between moraine basins. Such a lake is Lake Seliger on the Valdai Upland.
Volcanic lakes are located in the craters of volcanoes on the Kuril Islands, on the Kamchatka Peninsula. When a volcano erupts, such a lake boils away.
On the territory with permafrost, thermokarst lakes are formed. In summer, the permafrost thaws, the soil subsides, and shallow basins are formed, filled with melt water. There are many such lakes in Yakutia, the most famous is Lake Nejeli.
In river valleys common small lakes - oxbows- these are old riverbeds that have the shape of a horseshoe - since these are former river bends, meanders.
If there is a distribution of water-soluble rocks, for example, limestone, gypsum, dolomite, then in such areas karst lakes are formed. As a rule, they have a rounded shape.
Why are there a lot of lakes in some areas, while in others there are almost none? What are the conditions for the formation of lakes? ( Humid climate, excessive moisture; the presence of hollows; close occurrence of groundwater; close occurrence of waterproof layers that do not allow surface water to seep out).
Man is the force that creates artificial reservoirs - ponds and larger reservoirs. Most of the reservoirs are on the Volga. Why? (Several hydroelectric dams have been built here. The largest are Kuibyshevskoe, Rybinskoe, Cheboksarskoe. On Angara-Bratskoe.)
Lakes influence the components of nature:
It changes the microclimate, cooling and humidifying the air on the coast in summer. In autumn, frosts occur later near the lakes.
Contribute to raising the level of groundwater.
Lakes turn into swamps, where peat accumulates.
Salt lakes are accumulating salts. For example, in lakes Baskunchak and Elton.
They affect the relief: the waves of the lake destroy the shores, and accumulation processes take place at the bottom of the lake (deposits of sedimentary material - silt, sand, clay).
Swamps.
Guys! Guess the riddle: "Not the sea, not the land, ships do not float, but you cannot walk." What is it? (Swamp.) Each of you, for sure, has been to the swamp. Look at the world map. It shows in color how many percent of the area in each area of the Earth is occupied by swamps. Mainly in the Northern Hemisphere, the total area is about 350 million hectares. Around us are swamps, swamps, swamps ... Question? What is this such a swamp? Swamps are land areas where the soil is constantly or most of the year waterlogged.
In bog ecosystems, plant residues do not completely rot, and therefore not humus is formed, but peat.
How are swamps formed? What types of swamps do you know? Horse, lowland, transitional; by the predominance of vegetation: forest, moss, herbaceous, dwarf shrubs. Did you know that February 2 is World Wetlands Day? In 1975, the Convention on Wetlands, adopted on February 2, 1972, came into force, ratified by the Soviet Union 2 years later. Its main task is to protect sea bays, lakes and wetlands from chemical pollution. In Russia, 35 territories and water areas of wetlands of international importance are taken under protection, and another 166 sites are recommended for inclusion in the list of wetlands protected by the Ramsar Convention. Question? How do you feel about swamps? Most people say, "Bad!" The swamp is mosquitoes, mud, you can drown, it's scary there. Swamps are not useful, they interfere with agriculture. Only hunters and cranberry pickers will praise the swamps. This attitude was passed down to us in part from distant ancestors. The swamp, as a place difficult to access and unsuitable for human habitation, was rarely visited by people.
And where, if not in this remote place, should the "unknown and unclean forces" created by the rich people's imagination have settled? Superstitions are known to last a long time. Nowadays, attitudes towards swamps are changing. Question? What are the benefits of swamps? If forests are often compared with the lungs of our planet, and streams and rivers with its circulatory system, then the role of bogs in the biosphere can be compared with the role of the liver and kidneys in the body. The ability of swamps to purify water is striking. The marshes are even used to clean the sewage from pig farms! These drains not only smell bad, but are also poisonous. If you water the soil with them, the yield will decrease. Microorganisms that inhabit peat do an excellent job with these "aromas".
In the water flowing out of the swamp, there is not even a hint of what was drained into it from the pig farm! And the peat of such a "swamp swamp" becomes an excellent fertilizer. The main value swamps - the ability to store water and improve its quality. Swamps are the guardians of all other aquatic ecosystems that provide the biosphere with fresh and clean water. Question? Let's take a walk through the swamp! Afraid to walk on it? Yes, it is unsteady, boggy, but how, during the war, our troops went on the offensive along it with cannons and other equipment? Do you know what plants grow in the swamp? Well done! Indeed, there are not so many plants in the swamp, but they are very peculiar. These plants are not able to grow in other territories, as they cannot compete with other species. It is difficult for plants in a swamp: high humidity, air and heat poorly penetrate deep into the peat mass, the water is poor in nitrogen, and has an acidic reaction. Few plants can live in such conditions, because they have to constantly fight against the burial of living parts under a layer of growing peat. (The presenter tells and demonstrates slides.) Perhaps the most striking and well-known adaptation is the carnivorousness of some marsh plants (predatory plants!). They are able to "catch" and digest insects! We have such a plant in the swamps, only a very small one - the round-leaved sundew. Try an experiment with a sundew: "treat" it with a piece of meat or a boiled egg. You will see that the sundew will eat this treat without a trace!
I just want to call this plant a predator! But the sundew is a useful plant, a cough medicine is made from it. Question? What plant smells good in the swamp, but if you stay near it for more than half an hour, your head starts to hurt? This is wild rosemary, right. Its stems and leaves give off a volatile aromatic oil. And this plant is also a bog bush. He, like wild rosemary, leaves green leaves for the winter and with them hides from the frost under the snow. Its purple small flowers smell sweetly of nectar; bumblebees prepare a special honey from it. Do you know what this plant is called? I whipped it up. The relatives of the podbel are well known to all of you. These are cranberries, lingonberries, blueberries. How are they similar? These plants belong to the heather family.
They are united by the fact that they are all shrubs or semi-shrubs with woody stems and leathery leaves. They can be evergreen (like lingonberries) or deciduous (like blueberries). Their flowers resemble a glass in shape. Heather grow in the most unfavorable conditions: on sands, swamps, that is, where other plants cannot live.
One of the marsh sedges is called cotton grass. When ripe, fluff forms at the ends of the stems. They help small, light seeds fly away with the wind. Cotton wool was used to fill pillows and mattresses in villages near swamps, and even made fabrics from it. Assignment - a question? Do you know what a cattail looks like? Draw it. Hint: Popularly, it is often incorrectly called reed or reed. The cattail has two wonderful adaptations to survive the winter. The first is seeds. Those very velvet heads that you often admire in the summer. They consist of many seeds with dandelion-like flying hairs. The second adaptation is thick rhizomes that grow in muddy, muddy soil. They store nutrients for the winter.
The cattail will need them in the spring when it's time to wake up. Other plants, such as water lilies, have the same rhizomes. If you have been to the swamp, you have noticed what little pines and birches there are. Have you seen a real dwarf birch? How is it different from the usual birch that grows in almost every yard? Why is she so small in the swamp? Look at this cut of a pine tree that grew in a swamp. How old do you think she is? This pine tree is 40 years old! Due to the poor nutrition in the swamp, she had to grow up long and hard. And this is a cut of a pine tree that grew in good conditions, in the forest. She, of course, is not 40 years old, but much more, but when she was the same age as the swamp pine tree, it was just this diameter. Teacher. Guess another riddle. "Soft, not fluff, green, not grass." (Moss) Most of all moss in the swamp. They cover all bumps and depressions with a fluffy green-brown, brownish carpet.
And the most common among them is sphagnum. This moss has a wonderful property - it absorbs and retains a lot of water. Dozens of times more than it weighs itself! No wonder in translation from Greek "sphagnos" means "sponge". Sphagnum moss has a strong bactericidal (i.e., killing bacteria) effect. During the war, it was used for bandages. Sphagnum is also used for wall insulation (it is laid between the logs). Where else can this moss be applied? Teacher. We continue our acquaintance with bog secrets and riddles. Remnants of mosses, grasses, stems and leaves die off and lay in layers on top of each other. Tens or even hundreds of years pass, and in the swamp there is: - peat deposit. And what is the significance of peat. 1. Peat is a good fuel. Stoves have been stoked with it for a long time. 2. Peat is also an excellent fertilizer. If you add it to the soil, then you will definitely get a good harvest. 3. And for home flowers and seedlings, peat pots are made from peat. Why are they good? Keep in shape; planted plants receive fertilizers; seedlings can be planted in the ground together with a pot. 4. In medicine - peat therapy. The swamp is always a mystery, a mystery not only for us, but also for scientists. It is truly an undiscovered treasure trove from which we can learn not only about past landscapes, but also our history. In addition to the remains of plants, swamps store in their thickness the tools of labor and war of the past, and even the remains of the owners of these tools. So, in Britain, a knight was found in full armor... Despite all the mystery and enigma of the swamps, people have long settled near them. One of the Mansi nationalities - "na-ras-mahun" - is translated as "swamp people". And they consider the frog their ancestor. And the Mansi also believed that one of the sons of Numitorum (the supreme being) had the appearance of a frog.
Swamps are waterlogged areas of the terrain. Swamps are divided into two types: lowland and raised.
Lowland bogs are found where groundwater approaches the surface close to the surface. They are located in the depressions of the relief, they have a concave shape. Lowland swamps are impassable or impassable. Low-lying bogs, with the accumulation of a peat layer, break away from the groundwater supplying them and become upstream. To preserve raised bogs, the main condition is necessary - excessive moisture.
The most large area in Russia, swamps occupy the West Siberian Plain. Especially the territory of Vasyuganya, where swamps occupy 70% of the entire area. There are also many swamps in the Northwest of the Russian Plain.
Conditions for the formation of swamps:
- excessive moisture (k> 1);
- flat relief, slow runoff;
- overgrowth of lakes;
- proximity to groundwater;
- proximity to the surface of the water-resistant layer (permafrost, platform shield).
Why can't all the swamps be drained?
Water purification is underway in the bogs, and the bogs give rise to many rivers.
Valuable berries grow in the swamps - cranberries, cloudberries, blueberries.
Peat is formed in swamps, which is used as fuel and fertilizer.
Swamps are habitats for waterfowl - ducks, waders, geese, etc.
The groundwater.
Groundwater is the water found in the earth's crust. Their reserves are enormous. Groundwater - divided into groundwater and interstratal.
Groundwater is the water found in the earth's crust. Their reserves are enormous. Groundwater - divided into groundwater and interstratal. There is a permeable layer above the groundwater. In village wells (krinitsa) pound water. Groundwater comes out to the surface of the earth by springs, springs.
Interstratal waters occur deeper, between water-resistant strata. Reserves of interstratal waters are called artesian basins. They are obtained by drilling a well into interstratal waters - an artesian well.
Answer the questions:
What two types of groundwater do you know? (Soil, interstratal.)
How does the composition and quality of groundwater differ? (Thermal, mineral, fresh.)
What determines the depth of groundwater?
Why is there little water in the wells in winter and a lot in spring?
What serves as a waterproofing layer for groundwater in deserts? (Crystalline Foundation.)
How are thermal and mineral water?
Fresh groundwater is of the best quality drinking water that has passed natural filtration (mechanical cleaning).
Thermal waters are underground waters with temperatures from +30 to + 300 ° С. They are heated by magma in areas where volcanism is widespread (Kuriles, Kamchatka).
Mineral underground waters have a high concentration of dissolved substances and gases and are used for medicinal purposes.
The reserves and depth of groundwater are not the same in the regions and depend on the climate (moisture in the territory), the composition of rocks (water-resistant layer), relief (hollows).
Answer the questions:
- What two types of groundwater do you know? (Soil, interstratal.)
- How does the composition and quality of groundwater differ? (Thermal, mineral, fresh.)
- What determines the depth of groundwater?
- Why is there little water in the wells in winter and a lot in spring?
- What serves as a waterproofing layer for groundwater in deserts? (Crystalline Foundation.)
- How are thermal and mineral waters used by humans?
Permafrost.
Permafrost is underground glaciation, the upper layer crust having all year round negative temperatures and for hundreds and thousands of years, preserving ice in the ground. Permafrost occupies about half of the territory of Russia. The thickness of frozen soils in Yakutia reaches 1500 m, and the temperature is -16 ° C. In summer, the upper permafrost layer thaws from 20 cm in the Arctic to 2.5 m in the southern regions of the permafrost distribution.
The southern boundary of permafrost is shown on the soil map. In the European part of Russia, permafrost occupies the coast of the Arctic Ocean, the border in the Ural Mountains moves south to the latitudinal course of the Ob River, Eastern Siberia and Far East(except for Primorye) lie entirely within its boundaries.
When did permafrost form? Scientists believe that thousands of years ago, when there were several stages (periods) of cooling in the Quaternary period. The reason for the formation of permafrost is severe winters with little snow, short summer and the average annual temperature is below 0 ° C. V modern conditions permafrost persists in areas where the average annual temperature is below 0 ° C.
What effect does permafrost have on nature? Remember how the roots are distributed in larch? (In the surface layer.)
Permafrost inhibits plant development and soil formation processes. It also affects groundwater, being a water-resistant layer, retains moisture in the upper layers of the earth, and contributes to waterlogging of the territory. In winter, permafrost deprives the underground supply of the river, and they freeze to the bottom. Due to the permafrost, ice on the rivers "explodes" and ice forms (tarry). Permafrost is a relief-forming factor, forming permafrost landforms (bulguns, swelling mounds).
Permafrost also affects human economic activity. It significantly complicates the construction of buildings, roads, pipelines, mining. The pipelines are laid above the surface of the earth, because when the permafrost thaws, there is a danger of pipeline destruction. Houses on permafrost are placed on piles in order to preserve the permafrost soils, and, therefore, to avoid subsidence and destruction of buildings. But permafrost is also a natural "refrigerator" where you can store food.
As the story progresses, the teacher draws a diagram on the blackboard:
Glaciers.
Glaciers are accumulations of ice formed from snow.
Covering glaciers with a thick layer of up to 4 km lie on the Antarctic. In Russia, ice sheets are present on the Arctic islands. The area of ice on the islands is more than 55 thousand km 2, they make up more than 90% of the area modern glaciation Russia. There is as much water in the glaciers of the Arctic as the rivers of Russia carry out into the World Ocean in 3.5 years.
Glaciers flow down, breaking off as icy icebergs into the ocean.
In the mountains of the Caucasus, Kamchatka, Altai in the north of the Urals and in other mountains, mountain glaciation is widespread. The largest glaciers in Russia are the Bogdanovich Glacier in Kamchatka (about 17 km long) and the Bezengi Glacier in the Caucasus (17.6 km long).
The lower boundary of the glacier is the snow line, above which the snow that falls does not have time to melt in the warm season and turns into ice (firn and glacier ice). The farther south, the higher the snow line, and the more more precipitation(on windward slopes), the lower the snow line.
What role do glaciers play in nature and human life? (Glaciers give rise to mountain rivers... Terek and Kuban originate from glaciers, Katun from Katunskiye Belki in Altai.)
Where is the snow line higher in the northern Urals and in the Caucasus?
On the western or eastern slopes of the Koryak Upland?
Glaciers flow down, carrying frozen pieces of rocks with them, and reaching the border of the snow line, they melt, and the rocks form the final moraine, where the mountain river begins.
IV. Anchoring (geographic dictation)
Natural ice accumulations with independent movement. (Glacier.)
Areas of land that are excessively humid. (Swamps.)
What is the origin of the lake basins in the northwestern part of Russia? (Glacial tectonic.)
What kind of swamps by the type of food prevail in the steppes: low-lying or raised. (Lowlands.)
The deepest lake in Russia and the world. Its origin. (Baikal. Tectonic - formed in a fault in the earth's crust.)
What is the origin of the largest lake in the world? (Caspian- residual origin.)
Where is the snow line below - in Altai or in the Caucasus? (In Altai- harsh climate.)
What is the impact of permafrost on rivers? (The rivers are deep, the river network is denser, since the permafrost- waterproof layer.)
Why European part Is Russia poorer in inland waters compared to the Asian part? (In the Asian part, there is less evaporation and the presence of permafrost.)
Additional material to the lesson. Permafrost
Permafrost was known to Russian pioneers back in the 17th century. Siberian governors reported to Moscow about "land that does not melt." It caused particular difficulties in winter, when rivers froze over and fresh water springs dried up. Once the Yakut merchant Shergin, hoping to get to the water, dug a huge well. But, having reached a depth of 116 m, he abandoned his idea, since the frozen soils did not end. The permafrost thickness in Yakutia is 250-400 m. The well, which is known as the "Shergin mine", has survived to this day.
B.'s homework: 13; R.: 20.
I option: Make up questions and prepare an answer about lakes and glaciers.
Option II: On groundwater, permafrost and swamps. Additional material for the lesson
Soil ice is easily audible at the edge of the coastal slope. If you hit the edge of a steep descent to the water with your foot, then the rumble is loud and sonorous, as if glass is hidden under the ground. Root system woody plants due to permafrost, it is located very shallow, parallel to the surface of the earth. This reduces the stability of trees, and they are not always able to withstand the pressure. strong wind... At the same time, permafrost, gradually melting, provides continuous water supply to plants.
The age of the permafrost is many thousands of years, but not everywhere it turns out to be truly "eternal". The state of underground "refrigerators" in Russia is not constant. V last years the cold gradually recedes from the bowels of the planet. In the flat part of the Siberian tundra, it was not possible to build highways that would withstand more than five warm seasons. The repair of embankments is quite expensive, so cargoes have to be delivered to many areas via winter roads (winter roads) - during deep freezing of the soil in the cold season.
An important property of permafrost is its ability to preserve organic and inorganic substances and prevent decomposition. Permafrost is becoming a serious problem in the disposal of household waste. In the south of Siberia, permafrost processes are becoming more active during construction railways... At the beginning of the 20th century, the construction of embankments for roads led to a sharp increase in the thawing layer: on the mars (swampy plains), its depth increased 2 times. Because of these changes, road structures are spreading to the sides. Some sections of the Trans-Siberian Railway sank by 2.5 m. Thermokarst lakes and alases are often found in Yakutia (Dry depressions in the place of drained lakes). Lakes are formed on the site of melted underground ice. One of the artificially cleared areas was given for arable land, but it lasted only 15 years. Then the land began to settle, and a lake formed in the place of arable land.
Permafrost was known to Russian pioneers back in the 17th century. Siberian governors reported to Moscow about "land that does not melt." It caused particular difficulties in winter, when rivers froze over and fresh water springs dried up. Once the Yakut merchant Shergin, hoping to get to the water, dug a huge well. But, having reached a depth of 116 m, he abandoned his venture, since the frozen soils did not end there. The permafrost thickness in Yakutia is 250-400 m. The well, which is known as the "Shergin mine", has survived to this day.
Glaciers, reservoirs, and The groundwater.
The groundwater - these are waters that are under the surface of the earth, that is, in the strata of rocks in the upper part of the earth's crust.
The groundwater - component natural waters and one of the most important geological resources. They play a huge role in the nutrition and regulation of river flows, they are used for water supply. settlements, irrigation, treatment of people.
Groundwater is most widespread in the zone of excessive moisture with low relief.
Rocks, depending on their ability to pass water, are permeable (for example, sands) and waterproof (clays and crystalline rocks). Water that has passed through permeable rocks accumulates at a depth, lingering there above the water-resistant layer and thereby forming aquifers. We observe the emergence of such a layer on the surface in the form springs.
Groundwater trapped between two watertight layers is called artesian.
In deep aquifers lie artesian waters ... Huge reserves of groundwater are concentrated in artesian basins (for example, in Russia - Moscow, West Siberian). On the first waterproof layer from the surface of the earth, groundwater... Their reserves and depth of occurrence depend primarily on climatic factors. In areas of excessive moisture (tundra, forest), the groundwater level is close to the day surface, and they often hit in the form springs and keys.
| Rice. 144. Geysers |
In the south, evaporation exceeds precipitation and the water table decreases. Passing through various rocks, groundwater dissolves them a little and comes to the surface in the form mineral springs... Exclusively high quality have fresh waters: this is the best drinking water. Mineral waters with an increased content of mineral substances and gases have effective medicinal properties... Balneological sanatoriums are being built in places of mineral water reserves. The region of the Caucasian Mineral Waters with their famous narzans is very famous: the sulfur waters of Pyatigorsk, the alkaline-salt waters of Essentuki, the carbonic waters of Kislovodsk, the ferrous mineral waters of Zheleznovodsk.
Thermal waters, common in the Caucasus, Kamchatka, in Western Siberia, have an increased and high temperature(from + 30 ° to +300 ° C). Material from the site
Residential buildings, greenhouses are heated by thermal hot waters, they are used for spa treatment. In Russia, the first geothermal power plant was built on the basis of the Pauzhetskoye field of high-thermal groundwater in Kamchatka. Periodically gushing hot springs are called geysers(fig. 144). They are confined to the volcanic areas of Kamchatka and the Kuril Islands. The Valley of Geysers, located in the ridges of Eastern Kamchatka, is considered a natural wonder of Russia (Fig. 145).
On land there are five types of water accumulations : 1) groundwater, 2) rivers, 3) lakes, 4) glaciers, 5) swamps... Water is also present in the soil.
1. Groundwater
These are land waters located in the upper part of the earth's crust (to a depth of 12-16 km). Formed mainly by seepage atmospheric precipitation and the accumulation of water in the pores, cracks and voids of rocks. In relation to water, a distinction is made between permeable (sand, gravel), waterproof (clay, permafrost) and soluble (limestone, salt) breed.
According to the conditions of occurrence, there are soil (lie directly at the surface of the earth, in the soil), soils e (lie on the first waterproof layer) and interstratal (enclosed between two waterproof layers) of water. Interstratal waters are fed in areas where there is no upper water-resistant layer; can be pressurized, or artesian (if they fill the entire aquifer), and non-pressurized. Natural discharges of groundwater to the surface - sources , can be cold (up to +20 ° С), warm (+ 20-37 ° С) and hot (from +37 ° С).
2. Rivers
River- natural water stream, flowing in the same place continuously or intermittently.
! Read more about rivers in the synopsis.
3. Lakes
Lake- a closed natural depression on land, filled with water. It consists of a basin and a body of water. It is customary to classify lakes according to four criteria: the origin of the lake basins; the origin of the water mass; water regime; salinity. By origin, the lakes are divided into eight main groups.
- Tectonic lake basins are formed as a result of the formation of cracks, faults and subsidence of the earth's crust. They differ great depth and steep slopes (Baikal, Great North American and African lakes, Winnipeg, Big Slave, Dead Sea, Chad, Eyre, Titicaca, etc.).
- Volcanic, which are formed in craters of volcanoes or in depressions of lava fields (Kurilskoye and Kronotskoye in Kamchatka, many lakes of Java and New Zealand).
- Glacial lake basins are formed in connection with the activity of glaciers (lakes in Finland, Karelia, the Alps, the Urals, the Caucasus, etc.).
- Karst lakes, the basins of which arose as a result of sinkholes, soil subsidence and erosion of rocks. Dissolution of these rocks with water leads to the formation of deep, but insignificant lake basins.
- Zaprudnye lakes arise as a result of blocking the river bed with rock blocks during rock falls in the mountains (Sevan, Tana, many lakes of the Alps, Himalayas and other mountainous countries).
- Estuary lakes are widespread on the shores of the seas - these are coastal areas of the sea, isolated from it by means of coastal spits.
- Oxbow lakes are lakes that have arisen in old riverbeds.
- Residual lakes appeared on the site of the former seas.
The lakes are fed by atmospheric precipitation, groundwater and surface waters flowing into them.
By water regime u distinguish sewage and drainless lakes. The river (rivers) - Baikal, Onega, Ontario, Victoria, etc. flows out of the waste lakes. Not a single river flows out of the drainless lakes - the Caspian, Dead, Chad and others. The drainless lakes, as a rule, are more mineralized. Depending on the degree of salinity, the lake water is fresh and salty.
By origin the water mass of the lake are two types :
- lakes, the water mass of which is of atmospheric origin (such lakes prevail in number);
- relict, or residual, - were once part of the World Ocean ( Caspian lake and etc.)
The distribution of lakes depends on the climate, and therefore the geographical distribution of the lakes is to a certain extent zonal. Lakes have great importance : affect the climate of the adjacent territory (humidity and thermal conditions), regulate the flow of rivers flowing from them. Economic value lakes: used as communication routes (less than rivers), for fishing and recreation, water supply. Salts and medicinal mud are extracted from the bottom of the lakes.
4. Swamps
Swamps- excessively humid areas of land, covered with moisture-loving vegetation and having a peat layer of at least 0.3 m. Water in swamps is in a bound state. Swamps are formed as a result of overgrowth of lakes and waterlogging of the land.
Lowland swamps feed on soil or river waters, relatively rich in salts. Consequently, vegetation settles there, quite demanding food substances(sedge, horsetail, reed, green moss, birch, alder).
Upland swamps feed directly atmospheric precipitation... They are located on watersheds. Vegetation is characterized by limited species composition, because there is not enough mineral salts (wild rosemary, cranberry, blueberry, sphagnum mosses, pine). Transitional marshes occupy an intermediate position. Lowland and raised bogs are two stages in the natural development of bogs. Lowland swamp through an intermediate stage transitional swamp gradually turns into a horse.
The main cause of education huge swamps are characterized by excessive humidity of the climate, combined with high level groundwater due to the close occurrence to the surface of water-resistant rocks and flat relief.
The distribution of bogs also depends on the climate, which means that it is also zonal to a certain extent. Most swamps in the forest zone temperate zone and in the tundra zone. A large number of precipitation, low evaporation and water permeability of soils, flatness, weak dissection of interfluves contribute to waterlogging .
5. Glaciers
Glaciers– ice-converted land water of atmospheric origin. Glaciers are constantly moving due to their plasticity. Under the influence of gravity, the speed of their movement reaches several hundred meters per year. Movement slows down or accelerates depending on the amount of precipitation, warming or cooling of the climate, and in the mountains, tectonic rises affect the movement of glaciers.
Glaciers form where more snow falls during the year than has time to melt. In Antarctica and the Arctic, such conditions are created already at sea level or slightly higher. In equatorial and tropical latitudes snow can only accumulate on high altitude(above 4.5 km in equatorial, 5-6 km in tropical). Therefore, the height of the snow line is higher there. Snow line - the border above which the snow is not melting in the mountains. The height of the snow line is determined by the temperature, which is associated with the latitude of the area and the degree of continentality of its climate, the amount of solid precipitation.
The total area of glaciers is 11% land surface with volume 30 million cubic meters km... If all the glaciers melted, the sea level would rise by 66 m.
Covering glaciers cover earth surface regardless of the relief forms in the form of ice caps and shields, under which all the unevenness of the relief are hidden. The movement of ice in them occurs from the center of the dome to the outskirts in radial directions. The ice of these covers has tremendous power and does a lot of destructive work on its bed: it transfers debris, turning it into moraines. Examples of ice sheets are Antarctica and Greenland. Huge blocks of ice are constantly breaking off the edge of these ice sheets - icebergs. Icebergs can last up to 4-10 years before melting.
Mountain glaciers much smaller integumentary in size. In mountain glaciers the movement of ice occurs along the slope of the valley. They flow like rivers and sink below the snow line. As they move, these glaciers deepen the valleys.
Glaciers are reservoirs of fresh water created by nature. Rivers that begin in glaciers feed on them melt water... This is especially important for dry areas.
Permafrost
Permafrost. Permafrost, or permafrost, should be understood as a stratum of frozen rocks that do not thaw for a long time - from several years to tens and hundreds of thousands of years. Water in permafrost rocks is solid, in the form of ice cement. Permafrost occurs in conditions of very low winter temperatures, low altitude snow cover... These were the conditions that existed in the marginal areas of ancient ice sheets, as well as in modern conditions in Siberia, where there is little snow in winter and extremely low temperatures... The reasons for the spread of permafrost can be explained as a legacy ice age and modern harsh climatic conditions. Permafrost is nowhere so widespread as within Russia. The territory of continuous permafrost with a layer thickness of up to 600-800 m is especially distinguished. This territory has the lowest winter temperatures (for example, the mouth of the Vilyui).
Permafrost affects the formation of natural-territorial complexes. It contributes to the development of thermokarst processes, the appearance of heaving mounds, icing, affects the size and distribution of the underground and surface runoff by seasons, soil vegetation... In the development of minerals, the exploitation of groundwater, the construction of buildings, bridges, roads, dams, agricultural work, it is necessary to study frozen soils.
Summary of the lesson "Sushi Waters". Next topic:
Sushi water
5 (100%) 4 votes>> Lakes. Swamps. The groundwater. Glaciers. Permafrost
§ 24. Lakes. Swamps. The groundwater.
Glaciers. Permafrost
Lakes. There are about 3 million lakes in Russia. Among them, the deepest (1620 m) freshwater lake in the world is Baikal. Lake Baikal is famous not only as the deepest lake in the world. It contains half of the fresh water reserves of our country (23 thousand km 3), or more than half of the runoff of all rivers in the world. Baikal water is one of the cleanest in the world. 336 rivers flow into Baikal, and only one flows out - the Angara. The fauna of Lake Baikal is unique. 3/4 of the species of Baikal animals live only here. Russia along with Kazakhstan, Azerbaijan, Turkmenistan and Iran, it comes to the shores of the world's largest Caspian Sea-lake (area - 371 thousand km 2).
The distribution of lakes throughout the country is uneven and depends on many reasons: geological structure and relief and the terrain, climatic conditions, the peculiarities of the occurrence of groundwater. The number of lakes decreases significantly to the south due to increased aridity climate a.
The origin of the lake basins is diverse (see Table 10).
Name the largest lakes in Russia. Which lakes in our country have pits of the same origin as the largest lakes in Africa? Remember the main reasons for the formation of swamps. How are formed The groundwater?
On a physical map of Russia, give examples of areas with big amount lakes.
Lakes are sources of fresh water, food products, raw materials. For example, salt is mined in lakes Elton and Baskunchak.
Lakes regulate the flow of rivers. Navigable routes pass along them. There are numerous resting places on their shores. Lakes actively influence other components of nature. They change the topography, shaping the bottom and shores. By filling their basins with peat, silt and salts, lakes create deposits of minerals.
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