The hydrosphere is the water shell of the Earth. The water shell of the earth The water shell of the earth
Topic 3. Ecosystems and their features.
Topic 4. Cycles of substances.
Topic 5. Impact on the environment.
Conclusion.
List of used literature.
The water shell of the Earth.
The hydrosphere is the water shell of the Earth, which includes the World Ocean, land waters: rivers, lakes, swamps, glaciers and groundwater. The area of the hydrosphere is 70.8% of the surface area of the globe. The bulk of water is concentrated in the seas and oceans - almost 94%, and the remaining 6% falls on other parts of the hydrosphere. In addition to water in the hydrosphere itself, water vapor in the atmosphere, groundwater in soils and the earth's crust, there is biological water in living organisms. Under natural conditions, water occurs in three states of aggregation: gaseous, liquid and solid. From a chemical point of view, water is considered as hydrogen oxide (H2O) or oxygen hydride. Of the chemical properties of water, one of the most important is the ability of its molecules to dissociate, i.e. the ability to decompose into ions, as well as the colossal ability to dissolve substances of various chemical nature.
The water shell of the Earth is represented by the World Ocean, water bodies on land and glaciers in Antarctica, Greenland, polar archipelagos and mountain peaks (Fig. 3). The oceans are divided into four main parts - the Pacific, Atlantic, Indian, Arctic oceans. The waters of the World Ocean and its constituent parts have some common features:
- they all communicate with each other;
- the level of the water surface in them is almost the same;
- salinity averages 35%, have a bitter-salty taste due to the large amount of mineral salts dissolved in them.
Rice. 3. Comparative volumes of the atmosphere and ocean per 1 m3 of land.
Water is the most common solvent in nature. The growth and development of organisms depends on the amount of nutrients dissolved in water. The water content in different ecosystems, ranging from desert to lake and ocean, varies widely. Almost all living creatures on Earth need water, so it depends on its quantity and quality what type of community will be formed in a given ecosystem. The amount of available moisture in terrestrial habitats, in turn, depends on the amount of precipitation, air humidity and evaporation rate. In the aquatic environment, the factor of moisture availability can also have a certain effect on the nature of the communities distributed here. However, in these cases, unlike in terrestrial ecosystems, the availability of water is related to changes in water levels, such as during high and low tides. The availability of water may also depend on changes in the concentration of salts in it, and the concentration of salts, in turn, affects the rate of water entering and leaving the body.
To change the temperature of water or to change it from a solid phase (ice) to a liquid or gaseous phase (steam), a relatively large amount of heat is required. For this reason, water temperature changes much more slowly than air temperature. This property of water is extremely important for the life of aquatic organisms, which, thanks to this property, have a lot of time to adapt to temperature changes.
The density of water reaches its maximum at a temperature of 3.94°C. This means that at a given temperature, a certain volume of water (for example, 1 cm3) has the maximum of all possible values. As the temperature drops below 3.94°C, the density of water decreases. The temperature of ice formation is 00С. It becomes clear that a given volume of ice at 0°C is lighter than the same volume of water suspended at 3.94°C. This is why ice floats in cold water. This property of water is of great importance, because thanks to it freezing to the bottom of lake ecosystems is prevented. The surface layer of ice, as it were, creates thermal insulation for the underlying layers of water, and thus, a variety of aquatic organisms that live in the lake get the opportunity to survive the winter under the ice. Warm water is less dense than cold water, so the warm water layer is always on top of the cold water layer.
The concentration of salt in water is one of the most important environmental factors that determine which organisms will inhabit a given ecosystem. In freshwater animals and plants, the concentration of salts in extra- and intracellular fluids is higher than in their surrounding aquatic environment. Since substances tend to move from areas of high concentration to areas where their concentration is lower, water enters freshwater organisms, while salts, on the contrary, are excreted into the natural environment. In order to successfully cope with such a situation, freshwater organisms have developed special mechanisms or special organs have appeared. The evolution of freshwater organisms, in contrast to brackish ones, was in the direction of reducing the concentration of salts in their tissues and fluids. The concentration of salts in the cells and extracellular fluids of some inhabitants of salt water bodies (for example, in seaweeds and various marine invertebrates) is practically the same as in the aquatic environment around them. At the same time, in many marine inhabitants, the salt content in the visceral fluids is less than in the aquatic environment in which they live. Therefore, in this case, water is released from the extracellular and intracellular fluids of these organisms, while salts, on the contrary, enter them. Two different habitats (freshwater and brackish) provide different conditions for adaptation, and therefore they are inhabited by different communities of organisms.
In addition to freshwater and salt water reservoirs, there are brackish water reservoirs with an intermediate salt concentration. Such reservoirs are formed in places where salt and fresh waters mix, for example, in estuaries, i.e. semi-enclosed coastal waters freely connected to the open sea, or where saline water seeps into groundwater. Some species have completely or partially adapted to existence in conditions of intermediate salt concentration. As a result of evaporation, terrestrial animals and plants lose water. In this respect, they are similar to many marine organisms, which, like terrestrial species, must have developed mechanisms in the course of evolution to allow them to conserve water.
Sea water is a multi-element nutrient solution. Salinity of sea water varies depending on evaporation, river runoff and precipitation. The average salinity of ocean water is 35%. In the open ocean, it practically does not change. With the existing difference in the salt composition of river and sea water, the salinity of sea water should have changed during the existence of the planet, but this did not happen.
Not only salts are dissolved in ocean water, but also gases, the most important of which is oxygen, which is necessary for the respiration of living organisms. In different parts of the World Ocean, the amount of dissolved oxygen is different, which depends on the temperature of the water and its composition.
Sea water at a temperature of 10°C contains 1.5 times more oxygen than air. The presence of carbon dioxide in ocean water makes photosynthesis possible, and also allows some marine animals to form shells and skeletons as a result of life processes.
Fresh water is of great importance for the life of organisms. Fresh water is called water, the salinity of which does not exceed 1%. The amount of fresh water is 2.5% of the total, while almost two thirds of this water is enclosed in the glaciers of Antarctica, Greenland, polar islands, ice floes and icebergs, mountain peaks.
The total world fresh water resources are: total runoff - 38-45 thousand km3, water reserves in fresh lakes - 230 thousand km3, and soil moisture - 75 thousand km3. The annual volume of moisture evaporating from the surface of the planet (including transpiration by plants) is estimated at about 500-575 thousand km3, with 430-500 thousand km3 evaporating from the surface of the World Ocean; moisture. During the same time, 120 thousand km3 of water falls in the form of precipitation on all continents.
The groundwater- waters located in pores, cracks, caverns, voids, caves, in the thickness of rocks under the surface of the Earth. These waters can be in liquid, solid or gaseous state. Groundwater is a valuable mineral, a characteristic feature of which is the renewability in natural conditions and during operation.
Groundwater has a different origin and is divided into:
- juvenile, formed during magma processes;
- infiltration, formed due to the infiltration of atmospheric precipitation through the thickness of permeable soils and soils on waterproof layers;
- condensation accumulated in rocks during the transition of water vapor in the ground atmosphere to a liquid state;
- water buried by sediments in surface water bodies.
Underground waters are able to mineralize, such waters have healing properties that are used in resorts, sanatoriums and hospitals.
Reservoirs located in natural relief depressions.
The state water supply includes water for drinking and household needs, for industrial purposes, and possibly also for irrigation of city lawns. Irrigation water is designed to provide crops, its use is often seasonal, with high costs during the hot season. The suitability of rivers for navigation can be maintained by a constant discharge of water throughout the year. Recreation - such as rowing, picnicking, etc. – is ensured by maintaining a relatively constant volume of water in the reservoir so that its banks do not change much. Electricity generation requires both constant discharges of water and high water levels. For flood protection, it is necessary that the reservoir be kept, as far as possible, not completely filled. Conservation measures involve the release of water during low periods in order to protect the quality of the water and the species that inhabit it. These water additives dilute the wastewater, thereby reducing the oxygen required to decompose it in the water. They also allow for the expulsion of salt water from estuaries, maintaining a suitable habitat for the species that live there.
The multipurpose operation of reservoirs is complex. The reservoir, which performs only one function - the storage of water, must be constantly filled to the maximum. If the purpose of the reservoir is only flood control, it should not be filled so that even very abundant flood waters can be retained and then gradually released. The purpose and operation of any reservoir significantly affects the environment.
In natural depressions of the relief there are lakes, which are permanent reservoirs. Lakes are formed in various ways: from volcanic craters to tectonic troughs and karst sinkholes; sometimes there are dammed lakes during landslides and mudflows in the mountains.
First swamps appeared on our planet about 400 million years ago at the junction of two geological periods - the Silurian and the Devonian. The origin of swamps is associated with the accumulation of waters that do not have a runoff (Fig. 4). Bogs reduce the quality of the soil, are sources of peat and some types of fertilizers. Over hundreds of millions of years, peat layers have turned into coal horizons.
All peat bogs in the world occupy three percent of the land surface, or over 4 million km2. There are three groups of swamps, depending on how rich in minerals the waters feeding the swamp are. All peat bogs are divided into:
- riding (watershed) - moss, convex;
- low-lying (mainly valley and floodplain) - grassy and woody, flat, even;
- transitional.
Fig.4 Scheme of overgrowing of the lake according to A.D. Potapov.
- moss cover (ryam);
- bottom sediments of organic residues;
- "window" or space of pure water.
The main role in water exchange is played by lowland swamps in river valleys. They are fed by atmospheric, ground and surface waters. But it is lowland swamps that are practically not protected. They are unique in their ability to accumulate and preserve dead parts of plants, mosses, sedges, reeds, shrubs and trees in the form of peat in a water-saturated environment. Most swamps naturally grow, gradually increasing their reservoir. The water reservoir of swamps is 7 times larger than the reservoir of water in rivers and is comparable to the water reservoir of the atmosphere. Peat bogs account for 10% of the world's fresh water. Modern swamps are significantly different from fossils, their maximum age is 12 thousand years. Peat bogs are distributed over almost the entire earth's surface within all climatic zones. There is evidence of buried peat deposits even in Greenland, Svalbard and the Antarctic Islands. They are absent only in certain areas, for example, in countries with an arid climate. The largest number of peat bogs is located in the Northern Hemisphere. Russia has the world's largest peat reserves and is a leader in the study and use of peat resources. The area of peat bogs in our country is about 2/5 of the world. The largest peat region of the planet is the West Siberian Plain. 70% of all peat resources of the Russian Federation are concentrated here. The swamps of Western Siberia contain up to 1000 km3 of water.
Wet ecosystems of the planet play a huge role in creating balance in the carbon balance, since, as a result of photosynthesis, they deposit carbon oxides in the atmosphere and, thus, purify it. The carbon balance in the biosphere is determined by three main processes: carbon accumulation in the process of photosynthesis; the release of CO2 and CH4 during respiration; decomposition of organic matter and removal of carbon by surface and subsoil runoff into rivers and groundwater in the form of mobile mineral compounds.
The presence of swamps reduces the negative impact of drought and increases the productivity of vegetation. According to reports, a doubling of carbon dioxide in the atmosphere can cause a temperature rise on the planet by 3-5°C. According to the forecast of some scientists, by 2050 swamping will cover the entire globe.
Part of the swamp waters is involved in water exchange. Surface runoff from swamps is carried out through a hydrographic network, including watercourses, lakes, swamps, and also through filtration in the active horizon. In Western Siberia, where large swamp systems predominate, the volume of runoff ensures the formation of streams and rivers. The swamps do not feed the rivers - they carry out the transit function of redistributing the water entering them.
Abstract on the topic:
"WATER SHELL OF THE EARTH"
1. General information about water
2. World ocean
3. Groundwater
4. Rivers
5. Lakes and swamps
List of used literature
1. General information about water
Hydrosphere. The hydrosphere is called the water shell of the Earth. It consists of land waters - rivers, swamps, glaciers, groundwater and waters of the oceans.
The bulk of the water on Earth is in the seas and oceans - there it is almost 94%; 4.12% of water is contained in the earth's crust and 1.69% in the glaciers of Antarctica, the Arctic and in mountainous countries. Fresh water accounts for only 2% of its total reserves.
Water properties. Water is the most abundant mineral in nature. Pure water is clear, colorless and odorless. It has amazing properties that distinguish it from other natural bodies. This is the only mineral that exists in natural conditions in three states - liquid, solid and gaseous. Its transition from one state to another occurs constantly. The intensity of this process is determined primarily by the air temperature.
When water changes from a gaseous state to a liquid state, heat is released, and when liquid water evaporates, heat is absorbed. On sunny days and in summer, the water column warms up to a considerable depth and, as it were, condenses heat, and in the absence of sunlight or its decrease, heat is gradually released. For this reason, at night the water is warmer than the surrounding air.
When water freezes, it increases in volume, so an ice cube is lighter than a water cube of the same volume and does not sink, but floats.
The most dense and, accordingly, the most "heavy" water becomes at a temperature of +4 ° C. Water of this temperature sinks to the bottom of reservoirs, where such a temperature remains stable, which makes it possible for living organisms to exist in frozen reservoirs in winter.
Water is called the universal solvent. It dissolves almost all substances with which it comes into contact, except for fats and some minerals. As a result, pure water does not exist in nature. It is always found in the form of solutions of a greater or lesser degree of concentration.
Being a mobile (fluid) body, water penetrates into different media, moves in all directions and acts as a transporter of solutions. In this way, it ensures the exchange of substances in the geographical envelope, including between organisms and the environment.
Water has the ability to "stick" to the surface of other bodies and rise up through thin capillary vessels. This property is associated with the circulation of water in soils and rocks, the blood circulation of animals, the movement of plant juices up the stem.
Water is omnipresent. It fills large and small reservoirs, is contained in the bowels of the Earth, is present in the atmosphere in the form of water vapor, and serves as an indispensable component of all living organisms. So, the human body is 65%, and the bodies of the inhabitants of the seas and oceans are 80–90% water.
The value of water is not limited to the impact on life and economic activity. It has a huge impact on our entire planet. Academician V. I. Vernadsky wrote that "there is no natural body that could be compared with it (water) in terms of its influence on the course of the main, most vital geological processes."
Origin of water. It would seem that mankind knows everything about water. Nevertheless, the question of the origin of water on Earth is still open. Some scientists believe that water was formed as a result of the synthesis of hydrogen and oxygen released from the bowels of the Earth, others, such as academician O. Yu. Schmidt, believe that water was brought to Earth from space during the formation of the planet.
Together with cosmic dust and mineral particles, pieces and blocks of cosmic ice fell on the nascent Earth. When the planet warmed up, the ice turned into water vapor and water.
2. World ocean
division of the oceans. The oceans are divided into four main parts - oceans- Pacific, Atlantic, Indian and Arctic.
The waters of the oceans have a number of common features:
- all the waters of the oceans are interconnected;
- the level of the water surface in them is almost the same;
- The water of the World Ocean contains a significant amount of dissolved mineral salts and has a bitter-salty taste, which does not allow the use of this water for food purposes in natural conditions. The salinity of water is measured in ppm(%about). The ppm number shows how many grams of salt are contained in 1 liter of water. The average salinity of the World Ocean is 35%.
The waters of the World Ocean are unevenly distributed. In the Southern Hemisphere between 30–70 ° latitude, the ocean occupies more than 95%, and in the Northern - a little more than 44%, which made it possible to call the Southern Hemisphere oceanic, and the Northern - continental.
The waters of the World Ocean, going into the land, form seas and bays. The sea is a relatively isolated part of the ocean, differing from it in salinity and water temperature, and sometimes in the presence of a current. Thus, the salinity of the Baltic Sea ranges from 3 to 20%o, and the Red Sea - more than 40%o.
Bays are less isolated from the ocean, their waters differ little in properties from the waters of those oceans or seas to which they belong.
Historically, some typical seas have been referred to as bays. Such, for example, are the Bengal, the Hudson, the Gulf of Mexico. Some parts of the ocean are called seas conditionally in connection with the peculiarities of their nature. Such, for example, is the Sargasso Sea.
Depending on the geographical position, the seas are divided into mainland(Mediterranean, etc.) and inland(Baltic and others). According to the degree of isolation and features, they distinguish internal(Black, White, etc.), marginal(Barents, Okhotsk, etc.) and interisland(Javanese, Banda, etc.).
The seas and oceans are interconnected by straits - more or less narrow areas of water located between parts of the land. Straits usually have currents. Some straits are very extensive and carry huge masses of water (Drake Strait), others are narrow, winding and shallow (Bosphorus, Strait of Magellan).
In addition to salts, many gases are dissolved in ocean water, including oxygen, which is necessary for the respiration of living organisms. The cold waters of the polar seas contain more oxygen.
Marine animals use the carbon dioxide contained in the waters of the ocean to build skeletons and shells.
The water temperature in the oceans is not uniform and ranges from 27–28 °C at the equator to -20 °C at polar latitudes.
In temperate latitudes, there are seasonal temperature fluctuations from 0 to +20 °C.
The waters of the polar seas and oceans freeze. Ice sheet boundary runs from the shores of Newfoundland to the western coast of Greenland, then to the shores of Svalbard and the Kola Peninsula. In the Pacific Ocean, this boundary descends to the south and runs from the northern part of the Korean peninsula to the island of Hokkaido and further through the Kuril Islands to the shores of America.
In the Southern Hemisphere, the ice cover rises to 40–45°S. sh.
Traffic. The water in the oceans is in constant motion. There are three types of movements: wave, translational and mixed.
wave movements are generated by wind and cover only the surface of the ocean. Under the pressure of the wind in the upper part of the wave, water particles move in the direction of the wave, and in the lower part - in the opposite direction, making their way along circular orbits. For this reason, objects that are on the water and do not have windage do not move horizontally in the direction of the wind, but oscillate in place. It is no coincidence that these waves are called oscillatory.
Each wave has ridge, slope and sole(Fig. 30). The vertical distance between the crest and the sole is called the height, and between the two crests, the wavelength. The stronger the wind, the bigger the waves. In some cases, they reach a height of up to 20 m and even up to 1 km. Waves fade with depth.
Rice. thirty. wave structure
Under the pressure of the wind, the waves move faster towards the shore than away from the shore, as a result of which their foamy crests move forward, tilt and fall on the shore. Near the rocky shores, the force with which the wave beats against the coastal rocks reaches several tons per 1 m 2.
Underwater earthquakes generate waves tsunami, that cover the entire water column. The length of these waves is very large and amounts to several tens of kilometers. These waves are very gentle, and meeting them in the open ocean is not dangerous. The speed of the tsunami wave reaches 900 km/h. When approaching the coast, as a result of the friction of the wave on the ocean floor, its speed drops, the wave rapidly shortens, but at the same time grows in height, sometimes reaching 30 m. These waves produce devastating destruction in the coastal zone.
The translational movements of huge masses of ocean water lead to the appearance maritime or ocean currents. Such currents occur at different depths, as a result of which the water is mixed.
The main reason for the occurrence of currents is constant winds blowing in one direction. Such currents are called drift (surface). They involve in movement a mass of water up to 300 m deep and several hundred kilometers wide. This giant water stream - a river in the ocean - moves at a speed of 3 to 9-10 km / h. The length of such "rivers" can reach several thousand kilometers. For example, the Gulf Stream, starting in the Gulf of Mexico, has a length of more than 10 thousand km and reaches the island of Novaya Zemlya. This current carries 20 times more water than all the world's rivers combined.
Among the drift currents of the World Ocean, first of all, we should name the northern and southern trade wind currents, which have a general direction from east to west, caused by trade winds - constant winds blowing towards the equator at a speed of 30–40 km/h. Encountering an obstacle in the form of continents on its way, the currents change their direction of movement and move along the coasts of the continents to the south and north.
Depending on the temperature of the water, the currents are warm, cold and neutral.
The waters of warm currents have a higher temperature compared to the adjacent ocean water, cold waters have a lower temperature, and neutral ones have the same temperature. This is due to where the current brought water from - from low, high or the same latitudes.
The importance of currents on Earth is enormous. They serve either as “heating batteries” or as “refrigeration chambers” for the adjacent parts of the ocean and the mainland. The Gulf Stream, for example, has a temperature of 20-26 ° C, which is quite enough to "heat" Western Europe and warm the Barents Sea. At the same time, the cold Labrador Current causes the harsh, cold climate of the Labrador Peninsula, located at the latitude of France.
In addition, sea currents provide water exchange and mixing of equatorial, tropical, temperate and polar water masses, contribute to the redistribution of marine animals and plants. Where warm and cold currents meet, the organic world of the ocean is much richer and more productive.
In addition to drift currents, compensatory, runoff, and density currents are known.
Compensatory currents are caused by drift and are formed when winds from the mainland drive away surface waters. In place of these waters, compensating for their lack, water rises from the depths. She is always cold. For this reason, the cold Canary, California and Peruvian currents pass along the hot shores of Western Sahara, California, and Chile.
stock currents are formed due to the surge of water by drift currents, the removal of river waters or strong evaporation of water, as a result, leveling begins due to the runoff of adjacent waters. For example, due to runoff from the Gulf of Mexico, the Gulf Stream appeared.
Density currents are formed when two sea basins, the water of which has a different density, are connected by a strait. For example, the more salty and denser water of the Mediterranean Sea flows into the Atlantic Ocean along the bottom of the Strait of Gibraltar, and towards this flow along the surface of the strait there is a runoff current from the ocean into the sea.
Mixed movements of ocean waters include tides and low tide, resulting from the attraction of the Moon on the water surface of the ocean and the rotation of the Earth around its axis.
During the day, high and low tides occur twice, every 6 hours. In the open ocean, tidal and ebb waves are invisible, since their height does not exceed 1.5 m, and their length is very large. Near the coast, especially rocky, the wavelength is reduced, and since the mass of water remains the same, the wave height is rapidly increasing. For example, in the Bay of Fundy (North America), the height of the tidal wave reaches 20 m, in the Sea of Okhotsk (off the coast of Russia) it exceeds 13 m.
At high tide, large ocean-going vessels may enter seaports that are inaccessible to them at other times.
Tidal waves carry enormous energy, which is used to build tidal power plants (TPPs). In Russia, such a station has been created and is operating in Kislaya Bay on the Barents Sea. The value of TPPs is extremely high, primarily because they are environmentally friendly and do not require the creation of giant reservoirs occupying valuable land.
3. Groundwater
Underground waters are waters that are under the surface of the Earth in a liquid, solid and gaseous state. They accumulate in pores, cracks, voids of rocks.
Groundwater was formed as a result of seepage of water that fell to the surface of the Earth, condensation of water vapor that entered through the pores from the atmosphere, and also as a result of the formation of water vapor during cooling of magma at a depth and their condensation in the upper layers of the earth's crust. Of decisive importance in the formation of groundwater are the processes of seepage of water from the surface of the Earth. In some regions, for example, in sandy deserts, the main role is played by water coming from the atmosphere in the form of water vapor.
Water under the influence of gravity is called gravitational. It moves along the inclined surface of waterproof layers.
Water held together by molecular forces is called film. Water molecules that are in direct contact with rock grains form hygroscopic water. Film and hygroscopic water can be removed from the rock only by calcination. Therefore, plants do not use this water.
The root systems of plants absorb capillary water(located in the capillaries of the soil) and gravitational.
The rate of movement of groundwater is negligible and depends on the structure of the rocks. There are fine-grained rocks (clays, loams), granular (sands), fissured (limestones). Gravitational water flows freely through sands and along cracks at a rate of 0.5–2 m per day, in loams and loess - 0.1–0.3 mm per day.
Rocks, depending on their ability to pass water, are divided into permeable and waterproof. To permeable rocks sands belong to waterproof- clays and crystalline rocks. Water that has passed through permeable rocks accumulates at a depth above the impervious layer, forming aquifers. The upper level of the aquifer, called groundwater mirror, repeats the curves of the relief: above the hills it rises, under the basins it falls. In the spring, when the soil becomes very waterlogged when the snow melts, the groundwater level rises, and in winter it falls. The groundwater level also rises during heavy rains.
The outflow of an aquifer to the surface is called spring (source, key). Usually they are found in ravines, beams, river valleys. Sometimes springs can also be found on the plains - in small depressions or on the slopes of hills and hills (Fig. 31).
Rice. 31. descending (1) and ascending (2) sources
Groundwater enclosed between two waterproof layers is usually under pressure, so they are called pressure or artesian. Usually they are found at great depths - in the depressions of the bends of impervious layers (Fig. 32).
Rice. 32. Simple (1) , artesian (2) wells and spring (3)
Deep underground waters located near magma chambers give rise to hot springs. In Russia, they are found in Kamchatka, the North Caucasus and other places. The water temperature in them reaches 70–95 °C. The gushing hot springs are called geysers. More than 20 large geysers have been discovered in the Valley of Geysers in Kamchatka, among them the Giant, which ejects water to a height of 30 m, as well as many small ones. Outside of our country, geysers are common in Iceland, New Zealand, USA (Yellowstone National Park).
Passing through various rocks, groundwater partially dissolves them - this is how mineral springs are formed. Depending on the chemical composition, sulfuric (Pyatigorsk), carbonic (Kislovodsk), alkaline-salt (Essentuki), ferruginous-alkaline (Zheleznovodsk) and other sources are distinguished. They are used for medicinal purposes. Resorts are being built at their exit points.
4. Rivers
flowing waters - temporary streams, streams and rivers that level the surface of the Earth; they destroy hills, mountains, carry away the products of destruction to lower places.
The importance of flowing waters in human economic activity is also great. Springs, rivers and streams are the main sources of water supply. Settlements are located along streams and rivers, rivers are used as communication routes, for the construction of hydroelectric power plants and for fishing. In arid regions, river water is used for irrigation.
Rivers - These are natural permanent watercourses flowing along a slope and enclosed in banks.
Rivers often originate from springs that come to the earth's surface. Many rivers originate in lakes, swamps, and mountain glaciers.
Each river has a source, upper, middle and lower reaches, tributaries, mouth. Source is the place where the river originates. mouth- a place where it flows into another river, lake or sea. In deserts, rivers are sometimes lost in the sands, their water is used for evaporation and filtration.
Rivers flowing through a region form river network, which consists of separate systems including the main river and its tributaries. Usually the main river is longer, full-flowing and occupies an axial position in the river system. As a rule, it is older than its tributaries. Sometimes the opposite happens. For example, the Volga carries less water than the Kama, but is considered the main river, since its basin was historically inhabited earlier. Some tributaries are longer than the main river (the Missouri is longer than the Mississippi, the Irtysh is longer than the Ob).
The tributaries of the main river are divided into tributaries of the first, second and subsequent orders.
river basin name the territory from which it receives food. The basin area can be determined from large-scale maps using a palette. The basins of the various rivers separate watersheds. They often pass through hills, in some cases through flat wetlands.
Density of the river network is the ratio of the total length of all rivers to the area of the basin (km/km2). It depends on the relief, climate, local rocks. In places where there is more precipitation and evaporation is negligible, the river network is more dense. In the mountains, the density of the river network is greater than in the plains. So, on the northern slopes of the Caucasus Mountains, it is 0.49 km / km 2, and in Ciscaucasia - 0.05 km / km 2.
River nutrition. It is carried out by groundwater, as well as atmospheric precipitation in the form of rain and snow. Rainwater that falls on the surface partially evaporates, and part of it seeps into the depths of the earth or flows into rivers. Fallen snow melts in spring. Melt water flows down the slopes and eventually into the rivers. Thus, the permanent sources of river nutrition are groundwater, rain in summer and snowmelt in spring. In mountainous areas, rivers are fed by water from the melting of glaciers and snow.
The level of water in the rivers depends on the nature of food. The greatest rise in water in the territory of our country is observed in the spring, during the melting of snow. Rivers overflow their banks, flooding vast expanses. During spring floods, more than half of the annual volume of water flows down. In places where more precipitation falls in summer, rivers have a summer flood. For example, Amur has two floods: less powerful - in spring and more powerful - at the end of summer, during monsoon rains.
Observations of the level of rivers make it possible to distinguish periods of high and low water. They received the names "high water", "flood" and "low water".
high water- an annual recurring rise in water in the same season. In spring, when snow melts, a high water level is maintained in the rivers for 2-3 months. At this time, rivers flood.
high water- short-term non-periodic rise in water in rivers. For example, during heavy prolonged rains, some rivers of the East European Plain overflow their banks, flooding vast areas. On mountain rivers, floods occur in hot weather, when snow and glaciers melt intensively.
The height of the rise of water during floods is different (higher in mountainous countries, lower on the plains) and depends on the intensity of snow melting, rainfall, forest cover of the territory, the width of the floodplain and the nature of the ice drift. So, on large Siberian rivers, during the formation of ice jams, the rise of water reaches 20 m.
low water- the lowest water level in the river. At this time, the river is fed mainly by groundwater. In the central zone of our country, low water is observed at the end of summer, when water evaporates strongly and seeps into the ground, and also at the end of winter, when there is no surface nutrition.
According to the method of feeding, all rivers can be divided into the following groups:
– rain fed rivers(in the equatorial, tropical and subtropical zones - the Amazon, Congo, Nile, Yangtze, etc.);
- rivers receiving powered by melting snow and glaciers(rivers of mountain regions and the Far North - Amu Darya, Syr Darya, Kuban, Yukon);
– underground feeding rivers(rivers of mountain slopes in the arid zone, for example, small rivers of the northern slope of the Tien Shan);
– mixed-feed rivers(rivers of the temperate zone with a pronounced stable snow cover - Volga, Dnieper, Ob, Yenisei, etc.).
River work. Rivers are constantly producing work, which manifests itself in erosion, transport and accumulation of material.
Under erosion understand the destruction of rocks. Distinguish between deep erosion, aimed at deepening the channel, and lateral, aimed at destroying the banks. On the rivers you can see the bends, which are called meanders. One side of the river is usually washed away, the other is washed out. The washed-up material can be carried and deposited by the river. Deposition begins when the current slows down. First, larger material settles (stones, pebbles, coarse sand), then fine sand, etc.
The accumulation of the brought material is especially active in the mouths of the rivers. Islands and shoals are formed there with channels between them. Such formations are called deltas.
On the map you can see a large number of rivers that form deltas. But there are rivers, such as the Pechora, whose mouths look like an expanding wedge. Such mouths are called estuaries. The shape of the mouth usually depends on the stability of the seabed in the area where the river enters. Where it is constantly decreasing as a result of secular movements of the earth's crust, estuaries. In places where the bottom of the sea rises, deltas form. Rivers may not have deltas if a strong current passes into the sea in the area where the river flows, carrying river sediments far into the sea.
The structure of the river valley. River valleys have the following elements: channel, floodplain, terraces, slopes, bedrock banks. channel called the lower part of the valley through which the river flows. The channel has two banks: right and left. Usually one coast is gentle, the other is steep. The bed of a flat river often has a winding shape, since, in addition to gravity and friction, the character of the flow movement is also affected by the centrifugal force that occurs at the turns of the river, as well as the deflecting force of the Earth's rotation. Under the action of this force, at the turn, the flow is pressed against the concave bank, and the jets of water destroy it. The direction of the current changes, the flow is directed to the opposite, gently sloping shore. The deflecting force of the Earth's rotation causes the flow to press against the right bank (in the Northern Hemisphere). It collapses, the riverbed moves.
The process of formation of bends (meanders) is continuous. Sometimes the meander loops approach each other to such a distance that they connect, and the water begins to flow along a new channel, and part of the former channel becomes old woman, sickle-shaped lake.
In the course of lowland rivers, stretches and rifts usually alternate. stretches- the deepest sections of the river with a slow current. They are formed on its bends. rifts- small parts of the river with a fast current. They form in flat areas. The stretches and rifts are gradually shifting along the river.
The river constantly deepens the channel, but deep erosion stops when the water level in the river drops to the same level as at the confluence of the river into another river, lake, sea. This level is called erosion basis. The final basis of erosion for all rivers is the level of the World Ocean. With a decrease in the erosion base, the river erodes more strongly, deepens the channel; with an increase, this process slows down, sedimentation occurs.
floodplain called the part of the valley flooded with spring waters. Its surface is uneven: extensive elongated depressions alternate with small elevations. The highest areas coastal swells located along the coast. Usually they are covered with vegetation. Terraces are leveled platforms stretching along the slopes in the form of steps. On large rivers, several terraces are observed, they are counted from the floodplain upwards (first, second, etc.). There are from four to seven terraces near the Volga, and up to 20 on the rivers of Eastern Siberia.
slopes limit the valley from the sides. Often one slope is steep, the other is gentle. For example, the right slope of the Volga is steep, the left slope is gentle. The slopes end with bedrock banks, usually not affected by erosion.
Young rivers in the longitudinal profile often have areas with rapids(places with fast currents and rocky ground on the surface of the water) and waterfalls(areas where water falls from steep ledges). Waterfalls are found on many mountain rivers, as well as on such plains, in the valleys of which hard rocks come to the surface.
One of the largest waterfalls in the world - Victoria Falls on the Zambezi River - falls from a height of 120 m with a width of 1800 m. The noise of falling water can be heard for tens of kilometers, and the waterfall is always shrouded in a cloud of spray - mist.
The waters of Niagara Falls (North America) fall from a height of 51 m, the width of the stream is 1237 m.
Many mountain waterfalls are even higher. The highest of them is Angel on the Orinoco River. Its water falls from a height of 1054 m.
When building settlements, it is very important to know whether there is enough water in the river, whether it can provide water to the population and enterprises. For this purpose, define consumption, i.e., the amount of water (in m 3) passing through the living section of the river in 1 s.
For example, the speed of the river flow is 1 m / s, the area of \u200b\u200bliving section is 10 m 2. This means that the water flow in the river is 10 m 3 / s.
The flow of water in a river over a long period is called river runoff. It is usually determined from long-term data and is expressed in km 3 /year.
The amount of runoff depends on the area of the river basin and climatic conditions. A large amount of precipitation with little evaporation contributes to an increase in runoff. In addition, the runoff depends on the rocks that make up the territory and the terrain.
The high water content of the world's most full-flowing Amazon River (3160 km 3 per year) is explained by the huge area of \u200b\u200bits basin (about 7 million km 2) and the abundance of precipitation (more than 2000 mm per year). The Amazon has 17 tributaries of the first order, each of which brings almost as much water as the Volga.
5. Lakes and swamps
Lakes. About 2% of all land is occupied by lakes, land depressions filled with water. On the territory of our country (partially) there is the largest lake in the world - the Caspian and the deepest - Baikal.
Since ancient times, man has used lakes for water supply; they serve as communication routes, many of them are rich in fish. Valuable raw materials have been found in some lakes: salts, iron ores, sapropel. On the shores of the lakes, people have a rest, rest houses and sanatoriums have been built there.
Lake types. According to the nature of the runoff, the lakes are divided into flowing, runoff and non-drainage. AT flowing lake many rivers flow into it and several rivers flow out of it. This type includes Ladoga, Onega.
Waste lakes receive a large number of rivers, but only one river flows out of them. Lake Baikal and Teletskoye can be attributed to this type.
In dry areas are empty lakes, from which not a single river flows - the Caspian, Aral, Balkhash. Many tundra lakes also belong to this type.
The origin of lake basins is extremely diverse. There are basins that have arisen as a result of the manifestation of the internal forces of the Earth (endogenous). This is the majority of large lakes in the world. Small lakes are generated by the activity of external forces (exogenous).
To endogenous basins include tectonic and volcanic. Tectonic basins are subsided sections of the earth's crust. Subsidence can occur as a result of layer deflection or fault faults along fractures. Thus, the largest lakes were formed - the Aral (trough of the earth's layers), Baikal, Tanganyika, Upper, Huron, Michigan (fault).
Basins are volcanic are volcanic craters or valleys covered by lava flows. There are similar basins in Kamchatka, for example, Kronotskoye Lake.
Variety of lake basins of exogenous origin. In river valleys, oxbow lakes are often found, having an oblong shape. They arose on the site of former riverbeds.
Many lakes were formed during the Ice Age. Glaciers plowed out huge hollows during their movement. They filled with water. Such glacial lakes are found in Finland, Canada, in the north-west of our country. Many lakes are elongated in the direction of movement of glaciers.
In areas composed of water-soluble rocks - limestone, dolomite and gypsum - basins of karst origin are not uncommon. Many of them are very deep.
Lake basins are often found in the tundra and taiga. thermokarst, resulting from uneven thawing of permafrost.
In the mountains, as a result of strong earthquakes, impounded lakes. So, in 1911, Sarez Lake appeared in the Pamirs literally before the eyes of people: as a result of an earthquake, part of the mountain range was thrown into the river valley, and a dam with a height of more than 500 m was formed.
Many basins were created by man - this is artificial reservoirs.
In our country, the flow of most large rivers is regulated (Volga, Angara, Yenisei). They built dams and created large reservoirs.
Many lake basins have mixed origin. For example, Ladoga and Onega lakes are tectonic, but their basins have changed their appearance under the influence of glaciers and rivers. The Caspian Lake is the remnant of a large sea basin, which was once connected through the Kumo-Manych depression with the Azov and Black Seas.
The lakes are fed by groundwater, precipitation and rivers flowing into them. Part of the water from the lake is taken out into the rivers, evaporates from the surface, goes to the underground runoff. Depending on the ratio of the incoming and outgoing part, the water level fluctuates, which leads to a change in the areas of lakes. For example, Lake Chad in the dry season has an area of 12 thousand km 2, and in the rainy season it increases to 26 thousand km 2.
The change in the water level in the lakes is associated with climatic conditions: a decrease in the amount of precipitation in the lake basin, as well as evaporation from its surface. The water level in the lake can also change as a result of tectonic movements.
According to the amount of substances dissolved in water, lakes are divided into fresh, brackish and salty. Fresh lakes have dissolved salts less than 1%. brackish lakes are considered to be those where the salinity is more than 1% o, and salty– over 24.7%o.
Flowing and wastewater lakes are usually fresh, since the inflow of fresh water is greater than the outflow. Endorheic lakes are predominantly brackish or saline. In these lakes, the inflow of water is less than the outflow, so the salinity increases. Salt lakes are located in the steppe and desert zones (Elton, Baskunchak, Dead, Big Salt and many others). Some lakes are distinguished by a high content of soda, for example, soda lakes in the south of Western Siberia.
Lake life. Lakes develop depending on the surrounding conditions. Rivers, as well as temporary water flows, bring to the lakes a huge amount of inorganic and organic substances that are deposited on the bottom. Vegetation appears, the remains of which also accumulate, filling the lake basins. As a result of this, the lakes become shallow, and swamps can form in their place (Fig. 33).
Rice. 33. Scheme of overgrowing of the lake: 1 - moss cover (ryam); 2 – bottom sediments of organic remains; 3 - "window", or space of pure water
The distribution of lakes is zonal. In Russia, the densest lake network is observed in the areas of ancient glaciation: on the Kola Peninsula, in Karelia. Here the lakes are fresh, mostly flowing and rapidly overgrowing. In the south, in the forest-steppe and steppe zones, the number of lakes decreases sharply. Drainless salt lakes predominate in the desert zone. They often dry up, turning into salt marshes. Tectonic lakes are found in all belts. They have great depths, so the change is slow, hardly noticeable to humans.
Swamps. Swamps are overly moist areas of land covered with moisture-loving vegetation.
Bogging in the forest belt often occurs during deforestation. Favorable conditions for the formation of swamps are also in the tundra zone, where permafrost does not allow groundwater to penetrate deep into, and they remain on the surface.
According to the conditions of nutrition and location, the swamps are divided into lowland and upland. Lowland swamps are fed by atmospheric precipitation, surface and underground waters. Groundwater is rich in minerals. This causes rich vegetation in lowland swamps (alder, willow, birch, sedge, horsetail, reed, and rosemary from shrubs). Lowland swamps are widespread in the forest belt on the floodplains of large rivers.
Under certain conditions, lowland marshes can turn into riding. As peat grows, the amount of minerals decreases, and plants demanding mineral nutrition give way to less demanding ones. Usually these plants appear in the center of the swamp (sphagnum mosses). They secrete organic acids that slow down the decay of plant matter. There are rises from the peat. Water flowing into the swamp can no longer enter the center, where sphagnum mosses spread, feeding on atmospheric moisture. Raised bogs occur on poorly dissected watersheds.
Swamps occupy vast areas. Approximately 1/10 of the territory of our country is covered with swamps. Extensive areas of swamps in the Pskov, Novgorod regions, Meshchera and Western Siberia, many swamps in the tundra.
Peat is mined in the swamps, which is used as fuel and fertilizer.
List of used literature
1. Arutsev A.A., Ermolaev B.V., Kutateladze I.O., Slutsky M. Concepts of modern natural science. With study guide. M. 1999
2. Petrosova R.A., Golov V.P., Sivoglazov V.I., Straut E.K. Natural science and fundamentals of ecology. Textbook for secondary pedagogical educational institutions. Moscow: Bustard, 2007, 303 pages.
3. Savchenko V.N., Smagin V.P. Beginnings of modern natural science. Concepts and principles. Tutorial. Rostov-on-Don. 2006.
The water shell of the Earth as a habitat has many other properties that are important for its inhabitants. Water has a rather low content of dissolved oxygen in it. For large animals, whose body size does not allow breathing through the direct penetration of oxygen through the surface of the body, this circumstance has become a leading factor in the evolutionary formation of the principles of the respiratory system, which works with high efficiency.[ ...]
The water shell of the earth - the hydrosphere occupies approximately 71% of its surface. In nature, there is a continuous cycle of water.[ ...]
The hydrosphere is the water shell of the Earth, representing the totality of all water bodies on the planet: oceans, seas, rivers, lakes, swamps, glaciers, snow cover, groundwater. The composition of the hydrosphere also includes water in the atmosphere, soil moisture and water of living organisms. In the hydrosphere, the main phase states of water are represented - liquid, solid and gaseous. This is a continuous shell of the Earth, although sometimes invisible, in the case when it is represented only by water vapor or soil moisture.[ ...]
The hydrosphere is the water shell of the Earth. Due to the high mobility of water, they penetrate everywhere into various natural formations. Water is in the form of vapors and clouds in the earth's atmosphere, forms oceans and seas, exists in the form of glaciers in the highlands of the continents. Atmospheric precipitation penetrates into the strata of sedimentary rocks, forming groundwater. Water is capable of dissolving many substances, so any water of the hydrosphere can be considered as natural solutions of varying degrees of concentration. Even the purest atmospheric waters contain 10-50 mg/l of dissolved substances.[ ...]
The hydrosphere is the water shell of the Earth, which includes the World Ocean, land waters (rivers, lakes, glaciers), as well as groundwater.[ ...]
The hydrosphere is the water shell of the Earth. Water is an important component of all components of the biosphere and one of the necessary factors for the existence of living organisms. The bulk of the water (95%) is contained in the World Ocean, which occupies more than 70% of the surface of the globe; The depth of the World Ocean is on average about 4 kilometers, the greatest is about 11 kilometers. Water is contained in the form of vapors and clouds in the earth's atmosphere, exists in the form of glaciers in a frozen state, atmospheric waters penetrate into the thickness of sedimentary rocks, forming groundwater.[ ...]
The hydrosphere is the water shell of the Earth. Due to the high mobility, water penetrates everywhere into various natural formations, even the purest atmospheric waters contain from 10 to 50 mg/dm3 of soluble substances. The predominant elements of the chemical composition of the hydrosphere: hydrogen, oxygen, sodium, magnesium, calcium, chlorine, sulfur, carbon. The concentration of this or that element in water does not yet say anything about how important it is for the plant and animal organisms that live in it. In this regard, the leading role belongs to N, P, Si, which are absorbed by living organisms.[ ...]
Hydrosphere - the water shell of the Earth, including oceans, seas, rivers, lakes, groundwater and glaciers, snow cover, as well as water vapor in the atmosphere. The Earth's hydrosphere is 94% represented by salt waters of the oceans and seas, more than 75% of all fresh water is conserved in the polar caps of the Arctic and Antarctica (Table 6.1).[ ...]
Hydrosphere - the water shell of the Earth; contains 1.4 billion km3 of water, of which 90 million km3 are land waters. Seas and oceans occupy 71% of the surface of the globe. Fresh water reserves make up less than 2% of water resources. The total annual flow of rivers is 37 thousand km3. The annual runoff of underground rivers is 13 thousand km3. About 3/4 of the world's fresh water reserves are located in the ice of Antarctica, the Arctic, and glacial mountains. About 20% of the world's surface fresh water reserves are concentrated in Lake Baikal. The average salinity of the waters of the World Ocean is 3.5 g / l (in the oceans 48.1015 tons of salt).[ ...]
The hydrosphere is the water shell of the Earth, it includes the totality of surface waters, as well as water located within the lithosphere and atmosphere. The bulk of surface water is contained in the World Ocean, which occupies 71% of the surface of the globe and includes approximately 96% of the total free water supply. Ocean waters contain a significant amount of salts. The average salinity of ocean water is 3.5%, or 35 g/l. The share of fresh water is 2.5%, but 70% of this water is concentrated in ice sheets.[ ...]
Hydrosphere - the water shell of the Earth, which is a collection of waters of the oceans, seas, rivers, lakes, swamps, glaciers, snow cover, groundwater in liquid, solid and gaseous forms.[ ...]
The hydrosphere is the water shell of the Earth, located between the atmosphere and the lithosphere, and is a collection of oceans, seas, lakes, rivers, ponds, swamps, groundwater, glaciers and atmospheric water vapor. The hydrosphere is connected with other elements of the Earth - the atmosphere and the lithosphere. The waters of the earth are in constant motion. The water cycle links together all parts of the hydrosphere, forming a closed system as a whole. Without the hydrosphere, the existence of plants and animals is impossible, since their cells and tissues mainly consist of water. For example, a person consists of 65% water, and his daily physiological norm of water consumption is 1.5 ... 2.6 liters. In addition, an average person needs about 35 liters of water daily to meet hygiene needs.[ ...]
HYDROSPHERE is the water shell of the Earth, which includes the World Ocean, land waters (rivers, lakes, glaciers), groundwater. Water plays an important role in the history of the development of our planet, since the origin and development of living matter, and, consequently, the entire biosphere, is associated with it. The hydrosphere is in close relationship with the lithosphere (groundwater), the atmosphere (vaporous water) and living matter, of which it is an essential component. Water in the biosphere acts as a universal solvent, because it interacts with all substances, as a rule, without entering into chemical reactions with them. This enables the transport of solutes, such as the exchange of substances between land and ocean, organisms and the environment. From Table. 4 it can be seen that the vast majority of the hydrosphere (94%) falls on the World Ocean, followed by groundwater and glaciers.[ ...]
The hydrosphere is the water shell of the Earth, which includes the World Ocean, land waters (rivers, lakes, swamps, glaciers), groundwater. Water plays an important role in the history of the development of our planet, since the origin and development of living matter, and, consequently, the entire biosphere, is associated with it.[ ...]
The totality of all water bodies of the globe: oceans, rivers, lakes, groundwater, glaciers and snow cover - constitutes the water shell of the Earth - the hydrosphere.[ ...]
The World Ocean is the water shell of the Earth, with the exception of water bodies on land and the glaciers of Antarctica, Greenland, polar archipelagos and mountain peaks. The oceans are divided into four main parts - Pacific, Atlantic, Indian, Arctic oceans. The waters of the World Ocean, going into the land, form seas and bays. The seas are relatively isolated parts of the ocean (for example, the Black, Baltic, etc.), and the bays do not protrude into the land as much as the seas, and in terms of the properties of the waters differ little from the World Ocean. In the seas, the salinity of water can be higher than oceanic (35%), as, for example, in the Red Sea, up to 40%, or lower, as in the Baltic Sea, from 3 to 20%.[ ...]
The hydrosphere is the water shell of the Earth, including the resources of the oceans, seas, rivers, lakes, ponds, swamps, groundwater. The total amount of water on Earth reaches 1386 million km3, and the area of oceans and seas is 2.5 times larger than the land area. Of the total amount of water on Earth, the share of fresh water is slightly more than 2.5%, i.e. for each inhabitant of the Earth they account for about 5.8 million m3. However, less than 30% of these waters are available to humans, since the rest of them are concentrated in ice sheets (about 27 million km3), hidden in underground formations (the volume of underground fresh water is about 100 times the volume of surface water in lakes, rivers, swamps ).[ ...]
Origin of the Earth's geospheres. The age of the planet Earth is about 4.6 billion years. During this time, processes of transformation and movement of matter took place on the Earth, as a result of which the globe was divided into a number of shells, or geological spheres of geospheres). There are various spheres of the Earth: the core, the mantle, the earth's crust, the pedosphere, the lithosphere, the atmosphere, the hydrosphere, the pedosphere, the bzosphere, the noosphere, etc. The atmosphere (Greek "atmos" - steam) is the air shell of the Earth. Hydrosphere (Greek "hydra" - water) - the water shell of the Earth. Lithosphere (Greek "cast" - stone) - a hard shell of the globe. Pedosfera (lat. "pedis" - leg, foot) - the shell of the Earth, formed by the soil cover. Biosphere (Greek "bios" - life) - the shell of the Earth, transformed by living organisms. Noosphere (Greek "noo" - mind) - the shell of the Earth, transformed by human activity.[ ...]
The hydrosphere is the discontinuous water shell of the Earth. It is located between the atmosphere and the lithosphere and includes all oceans, seas, lakes, rivers, as well as groundwater, ice, snow of polar and high mountain regions. The hydrosphere is divided into surface and underground.[ ...]
The hydrosphere is a discontinuous water shell of the Earth, located between the atmosphere and the earth's crust. It includes the totality of all the waters of the planet: continental (deep, soil, surface), oceanic and atmospheric. The hydrosphere is the cradle of life on our planet. It plays a huge role in shaping the natural environment of our planet.[ ...]
The World Ocean - a continuous water shell of the Earth surrounding continents and islands - occupies about 70.8% of the earth's surface. Ocean waters are unevenly distributed between the hemispheres: in the Northern hemisphere they cover 66%, and in the Southern - 81% of the surface. According to geographical features, the World Ocean is divided into four parts, the main morphometric indicators of which are given in Table. 1.3.[ ...]
The hydrosphere is the water shell of the Earth, which includes the World Ocean, land waters (rivers, lakes, glaciers), as well as groundwater. The vast majority of the waters of the hydrosphere falls on the World Ocean (94%), followed by groundwater (4%) and glaciers (1.7%). Water acts as a universal solvent, as it interacts with all substances without entering into chemical reactions with them. Due to this feature, it ensures the exchange of substances dissolved in it between land and the ocean, living organisms and the environment. Water has played and continues to play a significant role in the formation and preservation of life on Earth. The first organisms appeared in water bodies, and only much later did the settlement of living beings begin on the surface of the land. It is also noteworthy that almost all functioning living systems consist mainly of water in the liquid phase: plants contain up to 85-95% of water, in the human body - 57-66%.[ ...]
The hydrosphere is called the water shell of the Earth. It consists of land waters - rivers, swamps, glaciers, groundwater and waters of the oceans.[ ...]
HYDROSPHERE [gr. hydôr water + sphaire ball] the water shell of the Earth is the habitat of hydrobionts, the totality of the oceans, their seas, lakes, ponds, reservoirs, rivers, streams, swamps (some scientists also include groundwater of all types, surface and deep).[ ...]
Hydrosphere (Greek "gidor" - water) - the water shell of the Earth. It is divided into surface and underground.[ ...]
The hydrobiosphere is the global world of water (the water shell of the Earth without groundwater), inhabited by hydrobionts.[ ...]
The hydrosphere is understood as the water shell of the Earth, including the oceans, seas, continental reservoirs and ice sheets of the continents. The hydrosphere is in constant interaction with the atmosphere and the upper part of the lithosphere. All natural waters are a single ecological system.[ ...]
The flow of energy reaching the solid and water shells of the Earth (the lithosphere and hydrosphere) is qualitatively different from that which enters the upper rarefied layers of the atmosphere. From all ultraviolet radiation, only hundredths and thousandths of calories per 1 cmg per minute fall on the earth's surface, and here rays with a wavelength of 2800-2900 A are not detected at all, while at an altitude of 50-100 km ultraviolet radiation still contains the entire range waves, including the shortest ones.[ ...]
Initially, the hydrosphere was understood as the water shell of the Earth, consisting of oceans, seas, lakes and rivers, as well as the ice shells of the continents. Later, underground gravitational (free) waters of reservoir horizons began to be included in the hydrosphere. The lower boundary of the underground hydrosphere was drawn along the deepest aquifers.[ ...]
The totality of the waters of the globe; water shell of the Earth.[ ...]
The process of dispersion in the geographic shell of the substance of the Earth's water shell is active. It is the most important supplier of water vapor to the air troposphere. Water vapor is an essential component of tropospheric air; as is known, it does not exist only in an ideal (theoretical) atmosphere that does not exist in nature. The distribution of water vapor and its derivatives with height justifies the previously adopted term dispersion. If the water vapor content near the earth's surface varies on average from 0.2% by volume in polar countries to 2.5% near the equator, then already at a height of 1.5-2 km it drops by half, and at a height of 10-12 km - 100 times.[ ...]
The global water cycle, connecting the water shell of the Earth, scattered in the air troposphere, and the hydrosphere buried in the earth's crust, serves as convincing evidence of the unity of the geographical shell. All structural parts of the geographic envelope are involved in the cycle, including the biostrome (absorption of water by vegetation followed by transpiration). One of the sides of the global water cycle is of exceptional importance for human life. In the process of circulation, and only thanks to it, there is a rapid renewal of fresh water resources. This is a gigantic in scale, continuously operating natural water desalination plant. The degree of desalination depends on the activity of water exchange. The more active water exchange, the less mineralization of water. The greatest mineralization is inherent in dead-end, according to M. I. Lvovich, links of moisture circulation (the Ocean, deep underground waters, drainless lakes of a closed part of the land). The exception is the polar glaciers - the conserved hydrosphere.[ ...]
The hydrosphere, as noted above, is the discontinuous water shell of the Earth, the totality of oceans, seas, continental waters (including groundwater) and ice sheets. Seas and oceans occupy about 71% of the earth's surface, they contain about 1.4 10 km3 of water, which is 96.5% of the total volume of the hydrosphere. The total area of all inland water bodies of land is less than 3% of its area. Glaciers account for 1.6% of water reserves in the hydrosphere, and their area is about 10% of the area of the continents.[ ...]
Characteristics of hydroresources and wastewater. The hydrosphere is called the water shell of the Earth. This is a collection of oceans, seas, lakes, ponds, swamps and groundwater. The hydrosphere is the thinnest shell of our planet, it makes up only 10 3% of the total mass of the planet.[ ...]
Oxygen is the most common chemical element on Earth. Bound oxygen makes up about 6/7 of the mass of the Earth's water shell. The hydrosphere contains 85.82% oxygen by mass, the lithosphere 47%, and in the atmosphere oxygen is in a free state and amounts to 23.15%.[ ...]
The study of the physical properties of natural water as a liquid and the physical processes occurring in the water shell of the Earth and its objects is carried out by hydrophysics - a branch of geophysics. The study of the composition and chemical properties of natural waters and their changes in time and space is the content of the geochemistry - hydrochemistry section.[ ...]
Modern life is distributed in the upper part of the earth's crust (lithosphere), in the lower layers of the Earth's air shell (atmosphere) and in the Earth's water shell (hydrosphere), Fig. 5.1.[ ...]
The scattered and buried hydrosphere constitute an inseparable whole of the corresponding structural part of the geographic shell - the earth's crust and the air troposphere. Therefore, they are not considered here. The water shell of the Earth consists of the World Ocean, lakes, rivers, glaciers, multi-year ice. Rivers, lakes, glaciers and multi-year ice are included in the structural fabric of the Earth's landscape sphere, separating in it in the rank of departments and classes of complexes. Their characterization is given in Chap. The World Ocean is subject to further consideration in this chapter.[ ...]
At present, work on the organization of irrigated agriculture for growing perennial grasses and vegetables in the steppe zone continues, but small irrigated fields with an area of tens (not more than 200-300) hectares are being created, water intake is carried out from artificial reservoirs in which spring snow water accumulates. Irrigation from lakes is prohibited, where interference with the hydrological regime is especially dangerous, as it can lead to irreversible changes in their ecosystems (for example, the disappearance of fish and blooming water, i.e., the massive development of cyanobacteria, etc.). HYDROSPHERE (G.) - the water shell of the Earth, including oceans, seas, rivers, lakes, groundwater, glaciers. The structure of the G. of the Earth is shown in Table. 16. G. is 94% represented by the salty waters of the oceans and seas, and the contribution of rivers to the planet's water budget is 10 times less than the amount of water vapor in the atmosphere.
Lecture 3
The hydrosphere is the water shell of the earth.
Pollution of the hydrosphere.
Sources of pollution of the hydrosphere.
Water quality control methods.
Water protection measures.
Waste water treatment methods.
The hydrosphere is the water shell of the Earth.
Hydrosphere- the water shell of the Earth, including all waters in liquid, solid and gaseous states.
The hydrosphere includes the waters of the oceans, seas, groundwater and land surface waters. Some water is found in the atmosphere and in living organisms.
Water occupies the predominant part of the Earth's biosphere (71% of the total area of the earth's surface).
The hydrosphere already 4 billion years ago was represented by the following three components: terrestrial (World Ocean, river, soil, lake waters, glaciers), underground (waters of the lithosphere), air (vaporous water of the atmosphere). The hydrosphere includes the following types of water (in brackets, the share of the total volume of water in the hydrosphere,%, according to M.I. Lvovich, 1974):
World Ocean (94.0);
groundwater (4.3);
glaciers (1.7);
land waters (lakes, river waters, soil moisture) (0.03);
atmospheric vapors (0.001).
Water is a part of living matter as an essential component (70–99%). In fact, living matter is an aqueous solution of "living" molecules. It is water that keeps them alive. Terrestrial life originated in the aquatic environment, and therefore it can be considered a derivative of water.
Fundamental properties of water:
1. First property hydrosphere - unity and ubiquity"(in the words of V. I. Vernadsky) natural waters. All waters are interconnected and represent a single whole. This unity of natural waters is determined by:
a) easy transition of water from one phase state to another. Three states are known within the limits of terrestrial temperatures: liquid, solid, and vapor. The plasma state of water exists at high temperatures and pressures in the deep parts of the bowels;
b) the constant presence of gas components in the water. Natural water is an aqueous solution (gas, suspended solids, minerals).
2. Second property hydrosphere is determined special structure of the water molecule. The structure and properties of water provide the most favorable conditions for the development of life on Earth. We know from physics that all bodies expand when heated and contract when cooled. Water behaves differently. If it contracted when it turned into ice (cooling), the ice would be heavier than water and sink to the bottom of rivers and lakes. The rivers would be frozen to the bottom, and life in these reservoirs would be impossible. Ice is an insulator that keeps the water below the ice from freezing, which protects all underwater life. If it were not for this property, then the Earth would turn into an ice-bound planet.
The special structure of the water molecule provides manifold structure it when changing external factors (temperature, pressure, chemical composition). In winter, we had to observe the diversity and beauty of ice patterns on the windows, snowflakes, frost on the trees. Just as no two drops of water are exactly alike, so no two types of water are identical in structure.
3. Third property hydrosphere is expressed in its geologically eternal mobility. The movement of water is very diverse and manifests itself in numerous cycles. The main movement of water is the geological cycle of matter. Every second, under the influence of solar heat, millions of cubic meters of water rise up and form clouds. The wind sets the clouds in motion. Under the right conditions, moisture falls in the form of rain or snow. Raindrops have a favorable size for everything earthly and fall quietly, softly. Are all life-friendly coincidences accidental? Thus, water is involved in a kind of cycles of matter and energy. This system was established on Earth with the advent of free water and continues to this day.
Why is there movement? Movement can occur under the action of: a) gravity; b) solar (thermal) energy; c) molecular motion with a change in the phase state.
4. Fourth property hydrosphere is determined by high chemical activity of water. Under the conditions of the earth's crust, there are no natural bodies that would not dissolve to some extent in natural waters. Water in the biosphere acts as a universal solvent, because, interacting with all substances, as a rule, it does not enter into chemical reactions with them. This ensures the exchange of substances between land and ocean, organisms and the environment.
The most important abiotic factors of the aquatic environment are the following:
1. Density and viscosity.
The density of water is 800 times and the viscosity is about 55 times that of air.
2. Heat capacity.
Water has a high heat capacity, so the ocean is the main receiver and accumulator of solar energy.
3. Mobility.
The constant movement of water masses contributes to maintaining the relative homogeneity of physical and chemical properties.
4. Temperature stratification.
A change in water temperature is observed along the depth of the water body.
5. Periodic (annual, daily, seasonal) temperature changes
The lowest water temperature is considered to be - 2 ° C, the highest + 35-37 ° C. The dynamics of fluctuations in water temperature is less than that of air.
6. Transparency and turbidity of water.
Determines the light regime under the water surface. The photosynthesis of green bacteria, phytoplankton, higher plants, and, consequently, the accumulation of organic matter, depends on transparency (and its opposite characteristic - turbidity).
Turbidity and transparency depend on the content of substances suspended in water, including those entering water bodies along with industrial discharges. In this regard, the transparency and content of suspended solids are the most important characteristics of natural and waste waters that are subject to control at an industrial enterprise.
7. Salinity of water.
According to the degree of salinity, all water bodies are conventionally divided into
fresh with salinity less than 0.50/00,
brackish water - salinity ranges from 0.5 - 16 0 / 00,
salty - more than 16 0 / 00.
The salinity of oceanic water bodies is 32 - 38 0 / 00,
Salt lakes have the highest salt content, where the concentration of electrolytes reaches 370 0/00.
Main difference sea water from river salt is that the vast majority of sea salt is chlorides, and in river water dominated carbonic salts. A person uses only fresh water for life support. Of the total water resources on earth, share of fresh water account for no more than 3%.
8. Dissolved oxygen and carbon dioxide.
The excess consumption of oxygen for the respiration of living organisms and for the oxidation of organic and mineral substances entering the water with industrial discharges leads to the depletion of the living population up to the impossibility of living in such water for aerobic organisms.
9. Hydrogen ion concentration (pH).
All hydrobionts have adapted to a certain pH level: some prefer an acidic environment, others prefer an alkaline environment, and still others prefer a neutral one. Changes in these characteristics can lead to the death of hydrobionts.
The hydrosphere is the water shell of the Earth.
Water on Earth. parts of the hydrosphere. World water cycle.
Oceans. Parts of the oceans. Methods for studying the sea depths. Properties of the waters of the oceans. The movement of water in the ocean. The use of maps to determine the geographical position of the seas and oceans, depths, directions of sea currents, water properties. The role of the World Ocean in the formation of the Earth's climates. Mineral and organic resources of the Ocean, their importance and economic use. Maritime transport, ports, canals. Sources of ocean water pollution, measures to preserve the quality of waters and the organic world.
Land waters. Rivers of the Earth - their common features and differences. River system. Nutrition and regime of rivers. Lakes, reservoirs, swamps. The use of maps to determine the geographical position of water bodies, parts of river systems, boundaries and areas of watersheds, and the direction of river flow. The value of surface waters for humans, their rational use.
The origin and types of groundwater, the possibility of their use by humans. The dependence of the groundwater level on the climate, the nature of the surface, the characteristics of the rocks. Mineral water.
Glaciers are the main accumulators of fresh water on Earth. Cover and mountain glaciers, permafrost: geographical distribution, impact on economic activity.
Man and the hydrosphere. Sources of fresh water on Earth. Problems associated with limited fresh water reserves on Earth and ways to solve them. Unfavorable and dangerous phenomena in the hydrosphere. Measures for preventing and combating dangerous phenomena, rules for ensuring personal safety.
Biosphere of the Earth. Diversity of flora and fauna of the Earth. Features of the distribution of living organisms on land and in the oceans. The boundaries of the biosphere and the interaction of the components of nature. adaptation of living organisms to their environment. biological cycle. The role of the biosphere. Latitudinal zonality and altitudinal zonality in flora and fauna. Human impact on the biosphere. Protection of flora and fauna of the Earth. Observations of flora and fauna as a way to determine the quality of the environment.
Soil as a special natural formation. The composition of soils, the interaction of living and non-living things in the soil, the formation of humus. The structure and diversity of soils. The main factors (conditions) of soil formation, the main zonal soil types. Soil fertility, ways to improve it. The role of man and his economic activity in the conservation and improvement of soils.
Geographical envelope of the Earth. The structure, properties and regularities of the geographical shell, the relationship between its constituent parts. Territorial complexes: natural, natural-anthropogenic. The geographic envelope is the largest natural complex of the Earth. Latitudinal zonality and altitudinal zonality. Natural zones of the Earth. Features of the interaction between the components of nature and human economic activity in different natural zones. The geographic envelope as the human environment.
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