The water shell of the Earth - the hydrosphere - is formed The groundwater, atmospheric moisture, glaciers and surface water bodies, including oceans, seas, lakes, rivers, swamps. All waters of the hydrosphere are interconnected and are in a continuous cycle.

The main composition of the hydrosphere is salt water. Fresh water accounts for less than 3% of the total volume. The figures are arbitrary, since only explored reserves are taken into account in the calculations. Meanwhile, according to the assumptions of hydrogeologists, in the deep layers of the Earth there are colossal underground water reservoirs, the deposits of which have yet to be discovered.

Groundwater as part of the planet's water resources

Groundwater - water contained in water-bearing sedimentary rocks that make up the upper layer of the earth's crust. Depending on environmental conditions such as temperature, pressure, rock types, waters are in a solid, liquid or vapor state. The classification of groundwater directly depends on the soils that make up the earth's crust, their moisture capacity and depth. Layers of water-saturated rocks are called "aquifers".

Aquifers with fresh water are considered one of the most important strategic resources.

Characteristics and properties of groundwater

Distinguish between unconfined aquifers, limited by a layer of impermeable rocks from below and called groundwater, and pressure, located between two water-resistant layers. Classification of groundwater by the type of water-saturated soils:

• porous in the sands;
• fissure filling voids of solid rock;
• karst, found in limestone, gypsum and similar water-soluble rocks.

Water, a universal solvent, actively absorbs substances that make up the rocks, and is saturated with salts and minerals. Depending on the concentration of substances dissolved in water, a distinction is made between fresh, brackish, salt water and brines.

Types of water in the underground hydrosphere

Water underground is free or bound. Free groundwater includes confined and unconfined waters capable of moving under the influence of gravitational forces. Among the associated waters:

• crystallization water, which is chemically included in the crystal structure of minerals;
• hygroscopic and filmic water, physically bound to the surface of mineral particles;
• solid water.

Groundwater reserves

Groundwater accounts for about 2% of the entire hydrosphere of the planet. The term "groundwater reserves" means:

• The amount of water contained in the water-saturated soil layer is natural reserves. Replenishment of aquifers occurs at the expense of rivers, atmospheric precipitation, overflow of water from other water-saturated strata. When assessing groundwater reserves, the average annual volume of groundwater flow is taken into account.
• The volume of water that can be used when opening the aquifer is elastic reserves.

Another term - "resources" - denotes the exploitable reserves of groundwater or the volume of water of a given quality that can be extracted from the aquifer per unit of time.

Contamination of groundwater

Experts classify the composition and type of groundwater pollution as follows:

Chemical pollution

Untreated liquid effluent and solid waste industrial and agricultural enterprises contain various organic and inorganic substances, including heavy metals, oil products, toxic pesticides, soil fertilizers, road reagents. Chemical substances penetrate into aquifers through groundwater and wells improperly isolated from adjacent water-bearing strata. Chemical pollution groundwater is widespread.

Biological pollution

Untreated domestic wastewater, faulty sewerage lines and filtration fields located near water intake wells can become sources of contamination of aquifers with pathogens. The higher the filtration capacity of soils, the slower it spreads biological pollution groundwater.

Solving the problem of groundwater pollution

Considering that the causes of groundwater pollution are anthropogenic in nature, measures for the protection of groundwater water resources from pollution should include monitoring of domestic and industrial wastewater, modernization of treatment and disposal systems Wastewater, limitation of effluent discharges into surface water bodies, creation of water protection zones, improvement of production technologies.

Atmospheric waters.

The content of water in the atmosphere is relatively small - about 0.001% of all its mass on our planet. The main sources of atmospheric moisture are surface water bodies and moist soil; in addition, moisture enters the atmosphere as a result of the evaporation of water by plants, as well as the respiratory processes of living beings. Water in the atmosphere is found in all three aggregate states- gaseous (water vapor), liquid (raindrops) and solid (snow and ice crystals). Condensation of water vapor leads to the formation of clouds; atmospheric moisture lost as a result of precipitation is replenished by the influx of new portions of evaporated water. Rain moisture, being in a cloud, already contains a certain amount of salt. In the course of powerful circulation processes that take place in cloudy masses, water and particles of salts, soil, dust, interacting, form solutions of the most diverse composition. According to Academician V.I. Vernadsky, the average salinity of the cloud is about 34 mg / l. Dozens are found in raindrops chemical elements and various organic compounds... Rain moisture in contact with atmospheric air, absorbs new portions of salts and dust. An ordinary raindrop weighing 50 mg, when dropped from a height of 1 km, "washes" 16 liters of air, and 1 liter of rainwater captures the impurities contained in 300 thousand liters of air. As a result, with every liter of rainwater, up to 100 mg of impurities enter the Earth. Atmospheric moisture also contains microorganisms, protozoa, algae, etc., which is united by the concept "Airplankton" .

All of the above impedes the use of atmospheric water as a source of household and drinking water supply, however, in waterless regions, it is used by the population for both household and drinking needs.

Surface waters.

Quality surface waters depends on the combination climatic and geological factors. The main climatic the factor is the amount and frequency of precipitation, as well as the ecological situation in the region. Falling precipitation carries with it a certain amount of undissolved particles such as dust, volcanic ash, plant pollen, bacteria, fungal spores, and sometimes larger microorganisms. The ocean is the source of various salts dissolved in rainwater. It contains ions of chloride, sulfate, sodium, magnesium, calcium and potassium. Industrial air emissions also "enrich" the chemical palette, mainly due to organic solvents and nitrogen and sulfur oxides, which are responsible for the fallout " acid rain"Agriculture chemicals also do their part."

Among geological factors include the structure of the river bed. If the channel is formed by limestone rocks, then the water in the river is usually clear and hard. If the channel is made of impermeable rocks, for example, granite, then the water will be soft, but turbid due to the large amount of suspended particles of organic and inorganic origin.

As sources of drinking water supply most commonly used rivers , which are natural runoffs of springs, swamps, lakes, glaciers. At the same time, the direct feeding of the rivers is carried out by rains, during the melting of the snow cover, by melt water from glaciers, as well as by underground sources. River waters characterized by a large amount of suspended solids, low transparency, high microbial contamination.

Lakes and ponds are natural or artificial pits, replenished with water mainly from precipitation and groundwater. These water sources are less suitable for drinking purposes, since they are significantly susceptible to pollution and have a poorly expressed ability to self-purify.

Artificial open water sources include reservoirs , which are created by the construction of dams that delay the watercourse. The quality of water in reservoirs depends on the composition of river, melt and ground waters, as well as on the condition of the bottom (bed) of the reservoir, which is a flooded area that was previously used in economic circulation.

In general, surface waters are characterized by relative softness (i.e. low amounts of mineral salts contained), a high content of suspended and colloidal substances and the presence of microorganisms. These waters are characterized by the inconstancy of the chemical and bacterial composition, which changes sharply depending on the seasons of the year and atmospheric precipitation.

The groundwater

A significant part of the rainwater falling out, as well as melt water, seeps into the soil. There, it dissolves the organic matter contained in the soil layer and is saturated with oxygen. Deeper are sandy, clayey, limestone layers. In them, organic matter is mostly filtered out, but the water begins to be saturated with salts and microelements. V general case, the quality of groundwater is influenced by several factors:

1) Rainwater quality (acidity, salt saturation, etc.).

2) The quality of the water in the underwater tank. The age of such water can reach tens of thousands of years.

3) The nature of the layers through which the water passes.

4) Geological nature aquifer.

Groundwater is subdivided into soil, unpaved and interstratal. This separation is due to the structure of the earth's crust. All rocks that make up the earth's crust are divided into permeable (sand, gravel, fractured limestone, etc.) and waterproof (granite, clay, etc.), impermeable to water. The alternation of these layers and the depth of their occurrence determine the conditions for the formation and composition of underground sources.

Soil water are located at the very surface of the earth in the form of a film of hygroscopic water. The soil water horizon is abundant in spring, dries up in summer and freezes in winter. Therefore, as a source of water supply, soil water is not used.

Ground water are located in the first aquifer from the earth's surface, accumulating on the first water-resistant (waterproof) layer at a depth of 1-2 to several tens of meters from the surface.

The most significant quantities in groundwater contain, as a rule, calcium, magnesium, sodium, potassium, iron and, to a lesser extent, manganese (cations). Together with the anions common in water - carbonates, bicarbonates, sulfates and chlorides - they form salts. The salt concentration depends on the depth. In the deepest waters, the concentration of salts is so high that they have a distinctly salty taste. The best quality water is obtained from limestone layers, but their depth can be quite large.

Groundwater is characterized by a fairly high salinity, hardness, low organic content and almost complete absence of microorganisms. Their quality is distinguished by a variety and variability of composition, although not to the same extent as the waters of surface water bodies.

These waters are used as sources of household and drinking water supply mainly in sparsely populated areas (especially in rural areas); water is taken using mine and pipe wells.

Interstratal waters represent groundwater, enclosed between two impermeable layers: the lower - lay down and the top - roof... A waterproof roof protects the aquifer (horizon) from precipitation and surface runoff. The interstratal horizons are fed at the places where they emerge on the earth's surface, sometimes at a great distance from the places of water use.

Interstratal waters are subdivided into gravity and pressure(artesian). Unlike groundwater, the mineral composition of interstratal waters depends on the duration of water contact with the rocks of the aquifer, as well as the composition and properties of the latter. The interstratal waters are characterized by significant fluctuations in the mineral composition in different places, the constancy of the composition in different seasons of the year, a low content of dissolved oxygen, favorable organoleptic characteristics, and an almost complete absence of microflora. Exceptions are cases when the waterproof roof is not continuous - it is thinned, cut by ravines or riverbeds, as a result of which groundwater can be polluted by surface runoff oxen.

Given the stability chemical composition, practical sterility, favorable organoleptic properties of interstratal waters, they are used primarily for drinking purposes, because, as a rule, they do not require special cleaning, and in some cases, disinfection.

To meet drinking and household needs of the population and sectors of the Russian economy from surface and underground sources annually taken within 2% of renewable resources and groundwater.

Total water intake from natural water bodies for all needs (including the intake of transit water) in 2004 amounted to 79.4 km 3, including fresh water from underground water bodies - 10.8 km 3 In recent years, the scale of water consumption and wastewater disposal, identified by state statistical monitoring, has been steadily decreasing. This reflects both a decrease in the number of reporting water users and real-life processes associated with water saving and a decrease in its consumption. Water management and water protection measures, changes in the structure economic activity and manufactured goods (services provided), the ongoing economic crisis in some types of activities and in a number of territories, clarification in accounting and other factors.

Total in Russian Federation in 2004, 61.5 km 3 of fresh water was used (in 1999 - 67.7 km 3), including from surface sources - 48.1 km 3 (53.1 km 3), from underground sources - 8, 2 km 3 (9.3 km 3), sea water - 5.2 km 3 (5.3 km 3).

A characteristic feature in the 90s of the XX century was an increase in water intake and discharge of polluted wastewater. From 1991 to 2000, it decreased by about 40%, the water intake for use decreased by only 29%, and the discharge of polluted wastewater by about 27%, which reflects the economic realities associated with the structural restructuring of the economy, the liquidation of many production facilities, previously in agriculture, savings in water intake and consumption in order to reduce the corresponding costs and a number of other factors.

In the national economy of the country, in quantitative terms, water consumption exceeds the total use of all other natural resources. This is largely determined by the existing structure of production in many industries, in which, for example, for processing 1 ton of oil, it is necessary to spend about 60 tons of water, for the manufacture of a conventional unit of fabric products - 1100 tons, synthetic fiber - up to 5000 tons of water. A similar picture is observed in agriculture: for the production of 1 ton of wheat, about 2 tons of water are needed, for the production of 1 ton of rice, more than 25 tons.

The most water-intensive sectors of the economy, consuming significant volumes of both surface and groundwater, continue to be energy, black and non-ferrous metallurgy, mechanical engineering, pulp and paper, fuel, chemical and petrochemical, food industry, as well as housing and communal services and agriculture. Moreover, if the industry as a whole in 2001-2005. the share of water used by the enterprises of the industry in the total utilities this level increased from 20 to 22% or more, and in agriculture - decreased from 20 to 18%.

Water losses in external networks during transportation from water sources to water consumers in 1991 amounted to 9.1 km3, in 2000 - 8.5 km3, and in 2004 - 8.0 km3. Significant volumes of withdrawn water are lost in the process of industrial production, as well as in utilities and agriculture due to imperfect technologies, leaks in water supply systems, etc. In recent years, the decrease in water losses is adequate to the decrease in water consumption. So, in 2001-2004. the volume of water withdrawn for use was reduced by 5%; the loss of water dropped by the same amount. In utilities, due to deterioration of water supply networks and imperfections shut-off valves, an average of 15–20% of water supplied to consumers is lost. Losses in irrigated

Surface land waters

Surface land waters include lakes, rivers, swamps and glaciers.

Lakes

Lakes are important objects of the hydrosphere, as they are reservoirs of fresh water. A lake is a depression on the land surface that is constantly filled with water.... The lakes are fed by atmospheric precipitation, surface waters flowing into them along the slopes, streams and rivers flowing into them, outlets at the bottom of groundwater. Distinguish sewage lakes from which the river (s) flows, and drainless in which water is consumed only by evaporation. The depression in which the reservoir is located is called lake basin... Depending on the causes (origin) of lake basins, the following lakes are distinguished: tectonic, volcanic, dam (dam), floodplain, glacial, karst, thermokarst and artificial (reservoirs).

Tectonic lacustrine basins are formed as a result of tectonic movements, leading to the sagging of sections of the earth's crust and to the subsidence of blocks of the earth's crust along faults with the formation of grabens. These are the largest and deep lakes- Caspian sea-lake, Aral sea-lake, Baikal, Tanganyika. Volcanic lakes are lakes formed in the craters of dormant or extinct volcanoes. Zavalny lakes are formed in the mountains as a result of the collapse of large masses of rocks, blocking the valley of a mountain river in the form of a dam, for example, Lake Sarez in the Pamirs. Floodplain lakes arise in river valleys as a result of separation from the channel of bends (meanders), which turn into closed elongated curved reservoirs - oxbows.

Glacial lakes are called lakes, the basins of which were formed as a result of plowing out or accumulative activity of glaciers. They are widely developed in areas subjected to ice sheets in the past. In areas where material drift (denudation) prevailed, there are mainly lacustrine plowing basins (lakes in Finland, Karelia, the Kola Peninsula), and in areas where moraine deposits accumulated in the form of hills and ridges, they formed in closed interhill depressions, numerous lacustrine basins of glacial accumulation (for example, lakes in the Valdai Upland or lakes in the southern part of the Karelian Isthmus).

Karst lakes are formed in areas where soluble carbonate rocks (limestones) develop. Among them, there are karst surface lakes, the basins of which were formed on the earth's surface as a result of the collapse of underground cavities, and karst underground lakes in karst caves. Thermokarst lakes arise in areas of permafrost distribution due to non-simultaneous thawing due to different reasons(mechanical composition of soils, vegetation, etc.) upper bound permafrost. As a result of thawing, saucer-shaped depressions are formed in the relief, which are filled with melt water.

Artificial lakes are created by man most often as a result of damming river valleys in order to generate electricity or to create the necessary water reserves for industrial, agricultural and domestic needs. Such lakes are called reservoirs... Artificial lakes are also formed as a result of filling with water from quarries.

In the distribution of lakes on Earth, there is a climatic zoning associated with the wetting of the territory, depending on the amount of precipitation and the amount of evaporation. The largest number lakes are observed in the tundra zone, fewer in the forest, very few in the steppe zone. The distribution on the earth's surface is also associated with the amount of moisture. fresh and salt lakes... Recall that water is considered fresh if no more than 1 g / liter of salts are dissolved in it, brackish - up to 25 g / liter, salty - from 25 to 37 g / liter and mineralized - over 37 g / liter. The waters entering the lake always contain some amount of dissolved salts. In the absence of a constant inflow of fresh water (rivers) in the lake, as a result of intensive evaporation, a gradual increase in the salinity of the lake water occurs. Therefore, salt lakes are usually confined to areas with a hot and dry summer climate and, as a rule, are drainless. The occurrence of salt lakes is also facilitated by the occurrence of salt-containing rocks within the catchment area. Depending on which salts are more distinguished soda, sulfate or chloride lakes. Self-precipitation of salts occurs in highly mineralized lakes, as, for example, in lakes Elton and Baskunchak.

Questions for self-control.

1. What is land surface water?
2. What is a lake?
3. What are the lakes, depending on the flow?
4. What is a lake basin?
5. What groups are lakes divided into depending on the origin of the basins?
6. How and in connection with what zoning is manifested in the distribution of the number of lakes on Earth?
7. What water is considered fresh, brackish, salty, mineralized?
8. What salt lakes are there, depending on the composition of the salts?

Rivers

Rivers play one of the main roles in the water cycle, carrying out the return of water to the World Ocean. The annual volume of water returned by all rivers on Earth is approximately 40,000 km 3. A river is a constant stream of water flowing in the channel it has developed, feeding on surface and groundwater... The place where the river originates is called source rivers, and the place of its confluence into a body of water (sea, lake, ocean) or into another river - mouth... Allocate home a river flowing directly into a body of water, and tributaries flowing into other rivers. The main river and its tributaries form river system... The earth's surface, together with the overlying soils and soils, from which river system collects its waters, called catchment river basin or simply catchment... The catchments of two neighboring rivers are separated by a watershed. Watershed Is a line dividing slopes directed in different directions, along which atmospheric waters run off. Allocate: World watershed that separates the river flow into different oceans; main watershed separating the basins of the main rivers; lateral watershed separating basins of adjacent tributaries main river... The rivers are divided into plain and mountain.

There are rivers due to the flow of water into them from various sources of food. There are 4 types of food: rain, snow, glacial and underground... Most often observed mixed nutrition. Depending on the location of the river and the season, this or that type of food predominates. For the equatorial, tropical and subtropical zones, rainfall is characteristic, for the temperate zone with cold snowy winters, snow nutrition. Rivers originating in high glacier-covered mountains are glacier-fed. Groundwater feeds rivers in winter and during absence rain food, thanks to which they do not dry out either in summer or in winter.

The main characteristics of the river are the flow rate, level and flow rate. Flow rate rivers depends on the fall and slope of the river. The fall rivers are the height difference between the source and the mouth of the river. Slope rivers is the ratio of the difference in the heights of the extreme points of the river section (or the entire river) to its (her) length, usually represented in%. The speed of the rivers flow varies considerably from a few centimeters per second in lowland rivers to several meters per second in mountain rivers. Speed water flow affects the rate of water renewal in the river. Rivers have a high rate of water exchange. On average, all the water in all the rivers of the world is renewed every 11 days.

Water level in the river is not constant. The change in level depends on the volume of water entering the river and is seasonal. The highest water levels are observed during intense snowmelt in spring and after prolonged or torrential rains. High level water associated with spring snowmelt is called flood, and the rise in the water level in the river, caused by rainfall - flood... The lowest water level in the river is called low water... During low water periods, the river is fed mainly by groundwater. Distinguish summer and winter low water.

Water level is closely related to water flow. Water consumption Is the volume of water in m 3 passing through the cross-section of the channel in 1 second. The largest flow rate of water has r. Amazon. On average, 220,000 m 3 of water per second flows through its cross-section at the mouth. In Russia, the highest flow rate is observed at the Yenisei - 19,800 m 3 / s. The discharge of water in the river for large periods of time (month, season, year) is called runoff... Fluctuations in the level and flow rate of the river characterize it water regime ... The water regime directly depends on the climate. For example, rivers such as the Amazon and Congo, located in humid tropical belt deep all year round because of the constant heavy rains there. Rivers flowing in areas with monsoon climate, are bottled only in summer, during the period monsoon rains... Rivers of the temperate zone freeze in winter and overflow in spring during snowmelt. High water, high water, summer and winter low water, freeze-up are phases of the water regime.

Questions for self-control.

1. What is a river?

1. What is stock?
2. What is the annual volume of river flow on Earth?
3. What is a river system, catchment, watershed?
4. What watersheds are there?
5. What types of rivers are fed?
6. What are the main characteristics of the river?
7. What is called high water, high water, low water?
8. What is water consumption?
9. What is water regime?
10. What are the phases of the water regime?

Swamps

Marshes are also important hydrospheric objects because they are accumulators of moisture and contain a large amount of it. It is in the swamps that the sources of many, including large rivers, are located. For example, the largest river in Europe, the Volga, originates from a swamp on the Valdai Upland. The reserves of water contained in all the swamps of the Earth are estimated at 11.5 thousand km 3. A swamp is a constantly waterlogged area of ​​the earth's surface with moisture-loving vegetation, as a result of the dying off of which peat is formed... Swamps arise as a result of overgrowth of lakes or excessive moisture of the earth's surface. In the case of overgrowth of lakes, their gradual shallowing first occurs due to the sedimentation of dusty and clay particles brought by the wind, as well as microscopic animals and algae, often in a large number... Then they settle in a shallow water body aquatic plants(water lilies, reeds, reeds), which, dying off, settle at the bottom, thereby increasing the rate of shallowing of the reservoir. As a result, the reservoir turns into a swamp, and from the former lake they remain in its deepest places. open areas water ("windows").

Excessive moistening of the earth's surface occurs either due to the proximity to the surface of groundwater, or as a result of the excess of the amount of atmospheric precipitation over the amount of evaporation. In both cases, waterlogging occurs in the territory, which consists in high soil moisture, which impedes the access of air (oxygen) to it, and in the settlement of moisture-loving vegetation (wild rosemary, various mosses, etc.). Mosses enhance the accumulation of moisture due to their high moisture content and reduce evaporation, thereby contributing to even greater waterlogging of the area. Swamps are widespread in forest and tundra zones.

Depending on the diet, lowland, horse and transitional swamps. Lowland swamps are located in depressions (for example, in river valleys) and are fed by groundwater that comes to the surface at the foot of the slopes or lies close to the surface. They have a concave, flat or slightly sloping surface. The vegetation of lowland bogs is quite diverse and is represented in the temperate zone by arboreal (alder, birch, willow) and herbaceous (sedge, reed, etc.) species. Grass bogs are widespread on the floodplains and in the deltas of large rivers.

Horse bogs are located most often on flat watersheds and are fed by atmospheric precipitation with low mineralization. They are also formed in the case of complete overgrowth of the lake. Due to the poor mineral nutrition, uniform vegetation is formed, represented by a carpet of sphagnum mosses and the common cotton grass, heather, dwarf birch, cranberries, etc. On the edges of the bogs, depending on the region, there are oppressed forms of pine or larch. Raised bogs have a convex surface as a result of the rapid growth of sphagnum mosses in the center of the bog, where mineral nutrition is minimal (sphagnum mosses are not very demanding on mineral nutrition).

Swamps transitional type in the nature of food and vegetation occupy an intermediate position between lowland and raised bogs. In low areas, where there is a connection with groundwater, vegetation of lowland bogs is developed, and in elevated areas (hummocks, elevations near trunks and stumps), vegetation of upland bogs.

Questions for self-control.

1. What is a swamp?
2. What types of swamps exist depending on the diet?
3. What is typical for lowland bogs?
4. What is typical for riding-type bogs?

5. What is typical for swamps transitional type?

Glaciers

Glaciers cover about 11% of the land surface. They contain about 30 million km 3 of pure fresh water. Glacier - a mass of ice moving along the earth's surface formed as a result of the accumulation and recrystallization of solid atmospheric precipitation (snow)... The largest cover glaciers are located in Antarctica, Greenland, large ones - on the islands of Iceland, Svalbard, New earth and Severnaya Zemlya. Snow accumulation can only occur above the conditional boundary, which is called snow line (border)... Above it, the accumulation of snow prevails over its melting and evaporation. The snow line at the poles drops to sea level, and at the equator it is located at an altitude of about 5 km. In the Caucasus, it is located at an altitude of about 3.5 km. The location of the snow boundary depends on climatic conditions and is subject to cyclicality. Therefore, glaciers can advance and recede, appear and disappear. V quaternary period due to global cooling and warming, there was a repeated change in the height of the snow boundary, which led to the appearance and disappearance of cover glaciers over large areas of the Earth.

Accumulating in depressions (depressions) or on flat surface snow under the influence of solar heat, thaws and compaction undergoes recrystallization, turning first into firn, and then as a result of the pressure of the overlying layers into ice. Ice under the influence constant pressure possesses fluidity. The flow of ice in glaciers occurs under the influence of its own weight and gravity. Thus, in the glacier there are accumulation area(food), where the ice volume increases, and area of ​​expenditure(decrease, runoff), where due to melting, evaporation or breaking off of ice, its mass decreases. Near mountain glaciers, the accumulation area is located above the snow border, below it descends along the valley glacier tongue related to the area of ​​ice consumption.

Cover glaciers form in high latitudes, where the snow boundary descends to the earth's surface and the accumulation of solid atmospheric precipitation exceeds their melting and evaporation. The center of the cover glacier is formed where the accumulation of snow is greatest, therefore it central part is an area of ​​accumulation. The ice cap has a convex shield-like shape due to the slow spreading of ice from the center to the edges. Its peripheral part is the area of ​​expenditure. The largest ice sheet is located in Antarctica. Its thickness is on average about 2 km, maximum - up to 4 km. The formation of this powerful ice sheet began in neogene period, 12 million years ago, during the general climatic cooling on the Earth. Its edges descend into the sea, forming ice shelves, some of which lie on the bottom, and the other is in a floating state. When the ends of ice shelves break off, icebergs... The largest icebergs reach the length of the first kilometers, and in height - up to 100 m. The largest part of the iceberg (up to 90% of the volume) is under water. Icebergs are carried out by sea currents and winds in more low latitudes where they gradually melt. Antarctic icebergs reach 45 ° S, and Greenland icebergs - 40 ° N, in rare cases they are observed in even lower latitudes.

Questions for self-control.

1. What is a glacier?
2. What proportion of the land surface is glaciers?
3. How much fresh water is concentrated in the glaciers of the Earth?
4. What kind of glaciers are there?
5. What is a Snow Boundary?
6. At what height is the snow border at the poles, at the equator, in the Caucasus?
7. What is a mountain glacier?
8. What is a cover glacier?
9. What is the maximum ice thickness of the ice sheet in Antarctica?
10. What is an ice shelf?
11. How are icebergs formed?

10. BIOSPHERE

All organisms (plants, animals, microorganisms (bacteria, viruses, etc.), fungi) that live on Earth make up a special living shell (film of life). This shell was first named "biosphere" in 1875 by the Austrian geologist E. Suess. In such a narrow sense, the biosphere is a collection of organisms that exist on Earth.... During the entire evolution of organisms (more than 3.5 billion years), there were about 500 million species of animals and plants on Earth. Today on Earth there are about 1.8 million species of animals and 0.5 million species of plants, and the biodiversity of fungi and microorganisms cannot be calculated, according to some estimates, it ranges from 3 or more million species.

Organisms are distributed extremely unevenly in the biosphere. The total mass of living matter per unit surface or volume of water, earth or air is called biomass Earth. On land, biomass decreases in 3 directions from equatorial latitudes, where it is maximum - to the side tropical deserts where there is a lack of water; then towards the polar latitudes and, finally, towards the high mountains, where there is a lack of heat. Land biomass far exceeds ocean biomass due to the predominance of plant biomass. The ocean is dominated by animal biomass, most of which is plankton. In warm equatorial and tropical latitudes huge species diversity organisms, but the number of individuals of each species is limited. In cold latitudes, on the contrary, the species diversity is limited, but the number of individuals of each species is large.

The spread of life on Earth was helped by the ability of organisms to adapt to a wide variety of environmental conditions. Some organisms are adapted to life on ice and at the bottom of deep ocean trenches. Organisms can live even in an aggressive environment: microorganisms have been found on the ocean floor in hot thermal springs with temperatures of about 300 ° C, in the lining of a nuclear reactor, in geyser water, anaerobic bacteria (capable of living without oxygen) have been found on great depth v earth crust... Therefore, it is not surprising that life spread very quickly on Earth.

The maximum concentration of organisms is at the border of contrasting environments: on the land surface, in the surface layer of the ocean, in the bottom layer of the ocean, at the boundaries of warm and cold currents, in the coastal land strip. All these are zones of contact between the lithosphere, hydrosphere and atmosphere.

A feature of living organisms is the constant exchange of matter and energy with the environment in the form of a biological cycle in nature. The essence of the cycle is reduced to two opposite processes - the creation organic matter at the expense of solar energy in the process of photosynthesis of plants and its further destruction with the help of microorganisms into simple mineral substances, which are then again assimilated by plants.

Organisms are actively involved in the general circulation of substances, changing the main nature-forming components. Almost all the oxygen in the atmosphere, and therefore the ozone layer, which saves all life on earth from the destructive ultraviolet solar radiation, created thanks to the vital activity of organisms. Organisms were removed from the atmosphere and transferred to sedimentary rocks (chalk, shell limestone, reef limestone, coal, oil shale) great amount carbon dioxide. As a result, the gas composition of the atmosphere changed and took state of the art... In addition, during their existence, organisms have absorbed and preserved in the form of fossil fuels a huge amount of solar energy. An example of such "conservation" can be peat, coal, oil and gas. They processed large masses of matter, creating soil cover planets.

It is estimated that oxygen in the atmosphere performs full turn through organisms in about 2 thousand years, and carbon dioxide- in 6.3 years. All water on Earth decomposes and recovers due to living organisms in 2 million years. In addition, it is known that organisms absorb almost all chemical elements. It can be stated that through living matter atoms of almost all chemical elements have passed many times. As a result, the circulation of substances on the Earth began to be biotic in nature.

Thus, over a long period of their existence, organisms have had a huge impact on the further evolution of geospheres, in which qualitative changes have occurred:

The process of photosynthesis was switched on and the gas composition of the atmosphere changed (the amount of CO 2 decreased and the content of O 2 increased), thus, the reducing environment was replaced by an oxidizing one;

The chemical and gas composition of the waters of the World Ocean is formed largely due to the influence of the biochemical activity of organisms;

Appeared in the lithosphere new type sedimentary rocks of organic origin (limestone, peat, coal, oil) and the processes of organic weathering began. organisms play very important role in the processes of soil formation and the formation of some forms of relief - for example, coral islands.

Organisms not only changed the circulation of substances on a global scale, but also began to play a defining geochemical role in the general circulation of substances. This is precisely what the great Russian scientist V.I. Vernadsky. He considered organisms taken as a whole, the most powerful force on the earth's surface in terms of its ultimate results... The state of the Earth in which the main role organisms play in the general circulation of substances, he called the biosphere. In this case, under the biosphere, he meant the sphere of activity of living organisms, the area of ​​interaction of living and nonliving (inert) matter, which includes the lower part of the atmosphere, the entire hydrosphere, upper part lithosphere and all organisms living on Earth. That is biosphere in broad understanding- this is the shell of the Earth, where the interaction of living and inanimate (inert) matter occurs, as a result of which the activity of organisms acquires global significance.

IN AND. Vernadsky, having created in the 20-30s. 20th century the doctrine of the biosphere, and determined the theoretical boundaries of the biosphere - from the ozone layer in the atmosphere at an average altitude of 20 km to a depth of 10 - 12 km in the lithosphere, where, according to calculations, the isotherm of 100 ºС is located. Consequently, the thickness (thickness) of the biosphere is about 30 kilometers. In practice, the biosphere is even less powerful. Expeditions to Everest showed that there are no reproductive organisms at an altitude of more than 7 km. In the lithosphere, organisms are apparently distributed to the depth of the groundwater.

Thus, there are two definitions of the biosphere: narrow and wide. On the one hand, it is only a set of organisms living on Earth (a film of life according to V.I.Vernadsky), and on the other, according to V.I. Vernadsky is the sphere of active interaction of shells. According to the authors, such a double meaning of the term "biosphere" confuses students and makes it difficult for them to perceive the material. Attempts to replace one of the terms were made repeatedly, but they did not receive widespread use. The authors propose to base the new term on the concept of “biota”. A biota is a collection of organisms that live in a large limited area and are not necessarily interconnected by food (trophic) chains.... For example, biota Western Siberia, biota of the Far East, etc. Planet Earth also has a limited area and it is perfectly legitimate to name the entire set of organisms living on Earth, biotosphere... In this case, the ambiguous interpretation of the concept of "biosphere" is excluded.

Currently, the biosphere is experiencing a strong anthropogenic impact of human economic activity, and the consequences of this impact are ambiguous:

On the one hand, man creates new species of plants and animal breeds; it accelerates the evolution of species in nature; enriches natural communities by acclimatizing living organisms; increases soil fertility; creates reserves protected natural areas,

On the other hand, there is an intensive destruction of natural vegetation and rare animals; the living conditions of living organisms (including the person himself) are deteriorating; destruction of soils occurs as a result of the processes of erosion and deflation.

Therefore, one of the most important problems of our time is the protection of the biosphere and rational use her wealth.

Questions for self-control.

1. What is called the biosphere and what components are included in it?

2. Where are the boundaries of the biosphere?

3. What are the features of the distribution of living organisms on Earth?

4. How did the emergence of living organisms affect the further evolution of the geospheres?

WATER RESOURCES or Cloudy Regime

"The dryness of the report is proportional to the amount of water in it."

“Take care of the water - take a shower with a girl”.

Water resources are suitable for consumption fresh water... They are enclosed in rivers, lakes, underground horizons, glaciers. Water vapor in the atmosphere sea ​​waters just like the absolute majority polar ice and waters of the deepest underground horizons are not currently used and are considered as potential water resources. Their future development depends on the improvement of mining technology, its economic feasibility, as well as on the solution of often unpredictable negative environmental issues arising from the use of unconventional water sources.

Water like natural resource :

Everyday life: drink, resource for cooking;

Life: plumbing system, sewerage system;

Industry: in manufacturing (as a cooler, "purifier", etc.),

Recreation: recreational resource;

Science, industry: a source of various chemical elements,

Agriculture: watering, other processes;

Transport: the possibility of using water bodies as transport lines;

As our civilization develops, the resources of fresh water on our planet are being depleted.

Over the past 30-40 years, the content of harmful pollutants in drinking water has increased enormously. Industrial waste such as toxic substances and heavy metals as well as agricultural pesticides and herbicides have become a Pandora's box. Opening it will have dire consequences for us and our children.

Usually waters are divided into surface and underground.

Surface water land - waters that flow (watercourses) or collect on the surface of the earth (bodies of water).

There are sea, lake, river, bog and other waters.

Surface waters are permanently or temporarily in surface waters water bodies... The objects of surface water are: seas, lakes, rivers, swamps and other streams and reservoirs. Distinguish between salty and fresh land waters.

As a rule, such waters contain very small amounts of minerals, therefore they are often called "soft water", even if this is not the case. Surface waters are exposed to many pollutants such as animal waste, pesticides, insecticides, industrial waste, algae and many other organic materials. Even surface waters originating from ancient mountain springs can contain the bacteria Giardia or Coliform Bacteria, which get there through animal excrement. That is, even water from mountain springs taken for drinking or cooking must be boiled or disinfected.

Underground water - all water that is in the mass of rocks in a solid, liquid or gaseous state.

On the continents, they form a continuous shell, which is not interrupted even in areas of dry steppes and deserts. Like surface waters, they are in constant movement and participate in the general water cycle in nature. The construction and operation of most surface structures and all underground facilities are associated with the need to account for the movement of groundwater, their composition and condition. The physical and mechanical properties and condition of many rocks depend on groundwater. They often flood construction pits, ditches, trenches and tunnels, and when they come to the surface, they contribute to waterlogging of the territory. Groundwater can be an aggressive environment for rocks. They are the main reason for many physical and geological processes occurring in natural conditions, in the process of construction and operation of engineering structures.

Rain sucked into the ground, rivers disappearing underground, melting snow are just a few of the resources that feed underground waters. Since there are many sources that feed groundwater, such waters may contain some or all of the pollutants found in surface waters, just as they contain dissolved minerals that are captured during their long way underground. Waters containing dissolved minerals such as calcium and magnesium, which are higher than the specified level, are called "hard water". Since water contains a "solvent", that is, over time it breaks the ionic bonds by which many substances are connected, this leads to the fact that such water dissolves and carries with it small amounts of everything it comes into contact with. For example, in places where limestone, gypsum, fluorite, megnetite, purite and magnesite are collected in the rocks, the water sources are very rich in calcium content and "hardness".

These two types of water are characterized by different characteristics therefore it is very important for you to know the origin of the water you use. Of the 326 million cubic miles of water on Earth, only 3% is pure; and 3/4 of it are frozen. Groundwater is only 0.5% of all groundwater; and only 0.02% of all water is in lakes and streams. An ordinary person is 70% water, that is, without it you can live no more than a week.