The purpose of the article below is to tell what the hydrosphere is, to show how rich our planet is in water resources, and how important it is not to upset the balance in nature. Planet Earth is covered with three shells. These are the atmosphere, lithosphere and hydrosphere. Through their interaction, life began. They accumulate solar energy and distribute it among all organisms.

Let's consider what the hydrosphere is.

Definition

To put it simply, these are all kinds of sources of precious liquid. This includes seas, oceans, rivers, glaciers, underground rivers and much more. Part of the hydrosphere is water in the atmosphere and in all living organisms. But the largest share is the salt water of the World Ocean.

If we consider from a scientific point of view what the hydrosphere is, then it is a complex of sciences that includes an entire division of research disciplines. Let's consider what sciences study the components of the hydrosphere.

• Hydrology. The scope of the study is surface water bodies of land: rivers, lakes, swamps, canals, ponds, reservoirs.
• Oceanology - studies the World Ocean.
• Glaciology - land ice.
• Meteorology - fluid in the atmosphere and its effect on weather and climate.
• Hydrochemistry - the chemical composition of water.
• Hydrogeology - deals with groundwater.
• Geocryology - water in a solid state: glaciers and eternal snow.
• Hydrogeochemistry is a young science that studies the chemical composition of the entire hydrosphere.
• Hydrogeophysics is also a new direction, the basis of which is the physical properties of the Earth’s water shell.

Composition of the hydrosphere

What does it consist of? The hydrosphere includes all types of moisture on the planet. Its volume is difficult to imagine. Scientists have calculated that it is 1370.3 million km 3. Throughout the history of the planet, the mass of water has never changed.

Interesting fact: Every fifth person dreams of drinking plenty of water. But no matter how much he drinks, he cannot do it.

Let's consider the composition of the hydrosphere:

• World Ocean. It occupies most, or rather, almost the entire volume of the water shell. It includes four oceans: Pacific, Atlantic, Indian and Arctic.
• Sushi water. This includes all sources of precious liquid that can be found on the continents: rivers, lakes, swamps.
• Groundwater is a huge supply of moisture located in the lithosphere.
• Glaciers and permanent snow, which account for a significant portion of water reserves.
• Water in the atmosphere and in living organisms.

The percentage of sources of the Earth's hydrosphere is presented in the figure below.

Water is a unique substance. Its molecules have such a strong bond that it is very difficult to separate them. But its even greater uniqueness is that, unlike other important elements, it can exist in natural conditions in three states at once: liquid, solid, gaseous.

The water cycle in nature plays an important role in the distribution of moisture on the planet. The main source of fresh liquid in the atmosphere is the World Ocean. From it, water, under the influence of the sun, evaporates, turns into clouds and moves in the atmosphere, but the salt remains. This is how fresh liquid appears.

There are two gyres: large and small.

The Great Water Cycle concerns the renewal of the waters of the World Ocean. And since most of the moisture turns into a gaseous state from its surface, it returns there along with the runoff, where it enters in the form of precipitation.

If the large cycle covers the renewal of water on the planet as a whole, then the small cycle concerns only the land. The same process is observed there: evaporation, condensation, precipitation and runoff into the World Ocean.

More water evaporates in the ocean than in rivers and lakes. On the contrary, there is a lot of precipitation on the continents, but little over open water spaces.

Speed ​​of circulation

The components of the Earth's hydrosphere are renewed at different rates. The supply of water in the human body is renewed most quickly, since it consists of 80% of it. Within a few hours, with plenty of drinks, you can completely restore balance.

But glaciers and the world's oceans are renewed very slowly. It takes almost 10 thousand years for completely new icebergs to appear in polar latitudes. You can imagine how long ice has already existed in the Arctic and Antarctica.

The water in the World Ocean clears a little faster - in 2.7 thousand years.

Nutritional power of living organisms

Water is a unique chemical compound of hydrogen and oxygen. It has no smell, taste, color, but easily absorbs them from the environment. Its molecules are difficult to separate, but at the same time they contain ions of chlorine, sulfur, carbon, and sodium.

Life originated in water, and it is contained in all organisms that carry out metabolism. There are animals whose bodies are almost liquid. Jellyfish are 99% water, fish are only 75%. There is even more juice in plants: in cucumber - 95%, carrots - 90%, apples - 85%, potatoes - 80%.

Functions of the water shell

The Earth's hydrosphere performs several vital functions for the planet:

1. Accumulating. All the energy from the Sun first enters the ocean. There it is stored and distributed throughout the planet. This process ensures that the average positive temperature is maintained.
2. Oxygen production. Most of this substance is produced by phytoplankton located in the World Ocean.
3. Distribution of fresh water due to gyres.
4. Provides resources. The world's oceans contain significant reserves of food, as well as other useful mined resources.
5. Recreational potential for a person who uses the ocean for his own purposes: for energy, cleaning, cooling, entertainment.

Hydrosphere and man

Depending on how water is used, there are two distinct categories:

1. Water consumers. This includes those branches of human activity that use transparent liquid to achieve their goals, but do not return it. There are a lot of types of such activities: non-ferrous and ferrous metallurgy, agriculture, chemical, light industry and others.
2. Water users. These are industries that use water in their activities, but always return it. This includes sea and river transport, fisheries, water delivery services to the population, and water utilities.

Interesting fact: for a city with a population of 1 million people, 300 thousand m 3 of clean drinking water per day is needed. In this case, the liquid returns to the ocean, contaminated and unsuitable for living organisms, and the ocean has to clean it up on its own.

Classification by nature of use

Water has different meanings for humans. We eat it, wash it and clean it. Therefore, scientists have proposed the following gradation:

• Drinking water is clean water without toxic and chemical substances, suitable for consumption in its raw form.
• Mineral water is water enriched with mineral components, which is extracted from the bowels of the earth. Used for medicinal purposes.
• Industrial water - used in production, undergoes one or two stages of purification.
• Thermal energy water is taken from thermal springs.

Process water

Water for technical needs can be completely different. In agriculture, it is used for irrigation, and there is no need to clean it. For energy purposes, for space heating, water is converted into a gaseous state. Hospitals, baths, and laundries receive household liquids with less purification.

Water used in industry is often contaminated. But more than half of the consumed volume is used to cool the units. In this case, it does not become dirty and can be reused.

Problems of the hydrosphere

The world's oceans are an environment that is capable of self-cleaning. But there are 7 billion people on Earth, and the rate of pollution is much greater than the rate of renewal. This can lead to irreparable consequences. Let's consider the main sources of hydrosphere pollution:

1. Industrial, agricultural, domestic wastewater.
2. Domestic waste from coastal areas.
3. Pollution with oil and petroleum products.
4. Release of heavy metals into the world ocean.
5. Acid rain, the result of which is the destruction of the areola of living beings.
6. Transport.

Pollution of seas and oceans

Man and the hydrosphere must exist in peace. After all, depending on how we treat the source of our life, nature will repay us. Already, the surface of the oceans and seas is very heavily polluted with oil products and waste. More than 20% of the water surface is covered with an impenetrable film of oil, through which oxygen and steam cannot be exchanged. This leads to the death of ecosystems.

Due to significant pollution, natural resources are depleted. A good example is the Aral Sea. Since 1984, there are no more fish here.

Since 1943, the hydrosphere has been polluted with dangerous radioactive substances. They were buried on the seabed. Since 1993, this has been prohibited. But over 50 years of harmful impact, man could cause irreparable harm to the ocean.

Danger from rivers and lakes

Land pollution is even more dangerous for humans. After all, it is from there that fresh water is taken for household needs and for food consumption. Today in Russia, most rivers are classified as highly polluted. Here is the ranking of the most dangerous bodies of water in Russia:

• Volga;
• Yenisei;
• Irtysh;
• Kama;
• Iset;
• Lena;
• Pechora;
• Tom.

Solving environmental problems

Humanity must understand that the more attention we pay to maintaining purity in nature, the greater the chance our descendants will have to live in a favorable environment. In pursuit of money and profit, many businesses neglect basic cleaning rules. The main task is the construction of purification filters in coastal areas, in places of greatest accumulation of waste, and providing enterprises with modern technologies aimed at environmental safety.

Afterword

From this article we learned what the hydrosphere is, what its main components are, and what problems the World Ocean faces. The task of each of us is to understand that the world was created not by man, but by nature, and we mercilessly exploit it, not realizing the consequences.

Many are accustomed to thinking that geography deals exclusively with one question: “How to get from point A to point B?” In fact, in the sphere of interests of this science there is a whole complex of serious and modern geography has a rather complex structure, which involves its division into many different disciplines. One of them is physical-geographical science. This is what will be discussed in this article.

Geography as a science

Geography is a science that studies the spatial features of the organization of the geographical shell of the Earth. The word itself has ancient Greek roots: “geo” - earth and “grapho” - writing. That is, the term “geography” can be literally translated as “description of land”.

The first geographers were the ancient Greeks: Strabo, Claudius Ptolemy (who published an eight-volume work called “Geography”), Herodotus, Eratosthenes. The latter, by the way, was the first to measure the parameters and did it quite accurately.

The main shells of the planet are the lithosphere, atmosphere, biosphere and hydrosphere. Geography focuses its attention on them. It explores the features of the interaction of the components of the geographic shell at all these levels, as well as the patterns of their territorial location.

Basic geographical sciences and areas of geography

Geographical science is usually divided into two main sections. This:

1. Physico-geographical science.
2. Socio-economic geography.

The first studies natural objects (seas, mountain systems, lakes, etc.), and the second studies phenomena and processes that occur in society. Each of them has its own research methods, which may differ radically. And if the disciplines from the first section of geography are closer to the natural sciences (physics, chemistry, etc.), then the second ones are closer to the humanities (such as sociology, economics, history, psychology).

In this article we will pay attention to the first section of geographical science, listing all the main directions of physical geography.

Physical geography and its structure

It will take a lot of time to list all the problems that interest physical geographers. Accordingly, the number of scientific disciplines numbers more than a dozen. Features of soil distribution, the dynamics of closed reservoirs, the formation of vegetation cover in natural areas - all these are examples of physical geography, or rather, the problems that interest it.

Physical geography can be structured according to two principles: territorial and component. According to the first, the physical geography of the world, continents, oceans, individual countries or regions is highlighted. According to the second principle, there is a whole range of sciences, each of which studies a specific shell of the planet (or its individual components). Thus, physical-geographical science includes a large number of narrow branch disciplines. Among them:

• sciences studying the lithosphere (geomorphology, soil geography with the basics of soil science);
• sciences that study the atmosphere (meteorology, climatology);
• sciences studying the hydrosphere (oceanology, limnology, glaciology and others);
• sciences that study the biosphere (biogeography).

In turn, general physical geography summarizes the results of research of all these sciences and derives global patterns of functioning of the geographical shell of the Earth.

Sciences that study the lithosphere

The lithosphere is one of the most important objects of research in physical geography. They are studied mainly by two scientific geographical disciplines - geology and geomorphology.

The solid shell of our planet, including the earth's crust and the upper part of the mantle, is the lithosphere. Geography is interested in both the internal processes that occur in it and their external manifestations, expressed in the relief of the earth's surface.

Geomorphology is a science that studies relief: its origin, principles of formation, dynamics of development, as well as patterns of geographic distribution. What processes shape the appearance of our planet? This is the main question that geomorphology is designed to answer.

Level, tape measure, protractor - these tools were basic in the work of geomorphologists once upon a time. Today, they increasingly use methods such as computer and mathematical modeling. Geomorphology has the closest connections with such sciences as geology, geodesy, soil science and urban planning.

The results of research in this science are of great practical importance. After all, geomorphologists not only study relief forms, but also evaluate it for the needs of builders, predict negative phenomena (landslides, landslides, mudflows, etc.), monitor the condition of the coastline, and so on.

The central object of study of geomorphology is relief. This is a complex of all the irregularities of the earth's surface (or the surface of other planets and celestial bodies). Depending on the scale, relief is usually divided into: megarelief (or planetary), macrorelief, mesorelief and microrelief. The main elements of any relief form are the slope, peak, thalweg, watershed, bottom and others.

The relief is formed under the influence of two processes: endogenous (or internal) and exogenous (external). The first originate in the strata and mantle: these are tectonic movements, magmatism, volcanism. Exogenous processes include two dialectically related processes: denudation (destruction) and accumulation (accumulation of solid material).

Among those in geomorphology, the following are distinguished:

• slope processes (landforms - landslides, screes, abrasive banks, etc.);
• karst (sinkholes, karrs, underground caves);
• suffosion (“steppe saucers”, pods);
• fluvial (deltas, river valleys, ravines, ravines, etc.);
• glacial (eskers, kamas, moraine humps);
• aeolian (dunes and dunes);
• biogenic (atolls and coral reefs);
• anthropogenic (mines, quarries, embankments, dumps, etc.).

Sciences that study soil cover

At universities there is a special course: “Geography of soils with the basics of soil science.” It includes related knowledge of three scientific disciplines: geography, physics and chemistry.

Soil (or ground) is the upper layer of the earth's crust, which is characterized by fertility. It consists of parent rock, water, and rotted remains of living organisms.

Soil geography deals with the study of general patterns of zonal distribution of soils, as well as the development of principles of soil-geographical zoning. Science is divided into general and regional soil geography. The latter studies and describes the soil cover of specific regions, and also compiles corresponding soil maps.

The main research methods of this science are comparative geographic and cartographic. Recently, the method of computer modeling has also been increasingly used (as in geography in general).

This scientific discipline originated in the 19th century. Its founding father is considered to be the outstanding scientist and researcher Vasily Dokuchaev. He devoted his life to studying the soils of the southern part of the Russian Empire. Based on his numerous studies, he identified the basic and patterns of zonal distribution of soils. He also came up with the idea of ​​​​using shelterbelts to protect the fertile soil layer from erosion.

The course "Geography of Soils" is taught at universities, geographical and biological faculties. The very first department of soil science in Russia was opened in 1926 in Leningrad, and the first textbook on the same discipline was published in 1960.

Sciences that study the hydrosphere

The Earth's hydrosphere is one of its shells. Its comprehensive study is carried out by the science of hydrology, within the structure of which a number of narrower disciplines are distinguished.

Hydrology (literal translation from Greek: “the study of water”) is a science that studies all water bodies on planet Earth: rivers, lakes, swamps, oceans, glaciers, groundwater, as well as artificial reservoirs. In addition, her research interests include processes that are characteristic of this shell (such as freezing, evaporation, thawing, etc.).

In its research, hydrology actively uses methods of both geographical science and methods of physics, chemistry, and mathematics. The main objectives of this science include the following:

• study of water cycle processes in nature;
• assessment of the impact of human activity on the condition and regime of water bodies;
• description of the hydrological grid of individual regions;
• development of methods and methods for the rational use of the Earth's water resources.

The Earth's hydrosphere consists of the waters of the World Ocean (about 97%) and land waters. Accordingly, there are two large sections of this science: oceanology and land hydrology.

Oceanology (the study of the ocean) is a science whose object of study is the Ocean and its structural elements (seas, bays, currents, etc.). This science focuses much attention on the interaction of the Ocean with continents, the atmosphere, and the animal world. In fact, oceanology is a complex of various small disciplines that are engaged in a detailed study of the chemical, physical and biological processes occurring in the World Ocean.

Today, it is customary to distinguish 5 oceans on our beautiful planet (although some researchers believe that there are still four of them). These are the Pacific Ocean (the largest), the Indian Ocean (the warmest), the Atlantic Ocean (the most turbulent), the Arctic Ocean (the coldest) and the Southern Ocean (the “youngest”).

Terrestrial hydrology is a major branch of hydrology that studies all surface waters of the Earth. In its structure, it is customary to distinguish several more scientific disciplines:

• potamology (subject of study: hydrological processes in rivers, as well as features of the formation of river systems);
• limnology (studies the water regime of lakes and reservoirs);
• glaciology (object of study: glaciers, as well as other ice located in the hydro-, litho- and atmosphere);
• swamp science (studies swamps and the features of their hydrological regime).

In hydrology, a key place belongs to stationary and expeditionary research. The data obtained from these methods is later processed in special laboratories.

In addition to all these sciences, the Earth's hydrosphere is also studied by hydrogeology (the science of groundwater), hydrometry (the science of hydrological research methods), hydrobiology (the science of life in the aquatic environment), and engineering hydrology (studies the influence of hydraulic structures on the regime of water bodies).

Atmospheric sciences

The study of the atmosphere is carried out by two disciplines - climatology and meteorology.

Meteorology is a science that studies all processes and phenomena occurring in the earth's atmosphere. In many countries of the world it is also called atmospheric physics, which, in general, is more consistent with the subject of its study.

Meteorology is primarily interested in such processes and phenomena as cyclones and anticyclones, winds, atmospheric fronts, clouds, and so on. The structure, chemical composition and general circulation of the atmosphere are also important subjects of study in this science.

The study of the atmosphere is extremely important for navigation, agriculture and aviation. We use the products of meteorologists almost every day (we are talking about weather forecasts).

Climatology is one of the disciplines included in the structure of general meteorology. The object of study of this science is climate - a long-term weather regime that is characteristic of a certain (relatively large) area of ​​the globe. Alexander von Humboldt and Edmond Halley made early contributions to the development of climatology. They can be considered the “fathers” of this scientific discipline.

The main method of scientific research in climate science is observation. Moreover, in order to compile a climatological characteristic of any territory in the temperate zone, it is necessary to carry out appropriate observations for about 30-50 years. The main climatic characteristics of the region include the following:

• Atmosphere pressure;
• air temperature;
• air humidity;
• cloudiness;
• wind strength and direction;
• cloudiness;
• amount and intensity of precipitation;
• duration of the frost-free period, etc.

Many modern researchers argue that global climate change (in particular, we are talking about global warming) does not depend on human economic activity and is cyclical. Thus, cold and wet seasons alternate with warm and wet ones, approximately every 35-45 years.

Sciences studying the biosphere

Habitat, geobotany, biogeocenosis, ecosystem, flora and fauna - all these concepts are actively used by one discipline - biogeography. It is engaged in a detailed study of the “living” shell of the Earth - the biosphere, and is located precisely at the junction of two large areas of scientific knowledge (which sciences we are talking about specifically is easy to guess from the name of the discipline).

Biogeography studies the patterns of distribution of living organisms on the surface of our planet, and also describes in detail the flora and fauna of its individual parts (continents, islands, countries, etc.).

The object of study of this science is the biosphere, and the subject is the peculiarities of the geographical distribution of living organisms, as well as the formation of their groups (biogeocenoses). Thus, biogeography will not only tell us that the polar bear lives in the Arctic, but will also explain why it lives there.

There are two large sections in the structure of biogeography:

• phytogeography (or geography of flora);
• zoogeography (or geography of animals).

A great contribution to the development of biogeography as an autonomous scientific discipline was made by the Soviet scientist V. B. Sochava.

In its research, modern biogeography uses a large arsenal of methods: historical, quantitative, cartographic, comparison and modeling.

Physical geography of continents

There are other objects that are studied by geography. Continents are one of those.

A continent (or continent) is a relatively large area of ​​the earth's crust, protruding above the waters of the World Ocean and surrounded by it on all four sides. By and large, these two concepts are synonymous words, but “continent” is a more geographical term than “continent” (which is more often used in geology).

On planet Earth it is customary to distinguish 6 continents:

• Eurasia (largest).
• Africa (hottest).
• North America (the most contrasting).
• South America (the most “wild” and unexplored).
• Australia (driest).
• and Antarctica (coldest).

However, this view of the number of continents on the planet is not shared by all countries. So, for example, in Greece it is generally accepted that there are only five continents in the world (based on the population criterion). But the Chinese are sure that there are seven continents on Earth (they consider Europe and Asia to be different continents).

Some continents are completely isolated by the waters of the Ocean (such as Australia). Others are connected to each other by isthmuses (like Africa and Eurasia, or both Americas).

There is an interesting theory of continental drift, which claims that they all used to be a single supercontinent called Pangea. And one ocean “splashed” around him - Tethys. Later, Pangea split into two parts - Laurasia (which included modern Eurasia and North America) and Gondwana (which included all the other, “southern” continents). Scientists assume, based on the law of cyclicity, that in the distant future all continents will again gather into one solid continent.

Physical geography of Russia

The physical geography of a particular country involves the study and characterization of such natural components as:

• geological structure and minerals;
• relief;
• climate of the territory;
• water resources;
• soil cover;
• Flora and fauna.

Thanks to the vast territory of the country, it is very diverse. Vast plains here border with high mountain systems (Caucasus, Sayan, Altai). The country's subsoil is rich in various minerals: oil and gas, coal, copper and nickel ores, bauxite and others.

Within Russia, seven types of climate are distinguished: from Arctic in the far north to Mediterranean on the Black Sea coast. The largest rivers of Eurasia flow through the territory of the state: the Volga, Yenisei, Lena and Amur. Russia also has the deepest lake on the planet - Baikal. Here you can see huge tracts of wetlands and enormous glaciers on the mountain peaks.

Eight natural zones are distinguished on the territory of Russia:

• Arctic desert zone;
• tundra;
• forest-tundra;
• zone of mixed and broad-leaved forests;
• forest-steppe;
• steppe;
• zone of deserts and semi-deserts;
• subtropical zone (on the Black Sea coast).

There are six types of soil within the country, among which chernozem is the most fertile soil on the planet.

Conclusion

Geography is a science that studies the peculiarities of the functioning of the geographical shell of our planet. The latter consists of four main shells: the lithosphere, hydrosphere, atmosphere and biosphere. Each of them is the object of study for a number of geographical disciplines. For example, the lithosphere and topography of the Earth are studied by geology and geomorphology; The atmosphere is studied by climatology and meteorology, the hydrosphere by hydrology, etc.

In general, geography is divided into two large sections. This is physical-geographical science and socio-economic geography. The first is interested in natural objects and processes, and the second is interested in phenomena that occur in society.

The water shell of the Earth - the hydrosphere - includes the seas and oceans (the World Ocean), all the waters of the land and atmosphere, groundwater, and ice. Of the total volume of water in the hydrosphere (1616 billion km 3), the salty waters of the World Ocean predominate (1370 million km 3); groundwater - about 60 million km 3, in the form of ice and snow - about 30 million km 3, in lakes and rivers - 0.75 million km 3, in the atmosphere - 0.015 million km 3. The hydrosphere is a single shell, because all the waters of the Earth are mutually connected and are in constant large and small, fast and slow cycles. Complete renewal of water occurs in different ways: groundwater is renewed over many thousands, or even millions of years, the waters of the World Ocean - over 3 thousand years, lakes - over 300 days, rivers - over 12 days, atmospheric water vapor - over 9 days . The hydrosphere is an accumulator of solar heat and its redistributor on Earth.

Over the course of geological history, significant changes have apparently occurred in the hydrosphere. However, little is known about them. It has been calculated, for example, that during the ice ages the amount of ice sharply increased and, due to this, the volume and level of the World Ocean decreased (by tens of meters). Currently, the hydrosphere is undergoing transformations of unprecedented speed and scale associated with the technical activities of mankind. About 5 thousand km 3 of water is used annually, and about 10 times more is polluted. Some countries have begun to experience a shortage of fresh water. All this does not mean that there is not enough of it on Earth: we simply have not yet learned how to use water rationally.

The natural waters of the planet are studied by various sciences. Hydrology deals with surface waters of land (a section of hydrology devoted to the study and description of individual water bodies - rivers, lakes, reservoirs - hydrography). Oceanology studies the World Ocean, glaciology - ground ice, meteorology - atmospheric waters, hydrochemistry - the chemical composition of surface waters, hydrogeology - underground waters, geocryology - waters in the depths of the lithosphere in their solid state (permafrost), etc. For the role of general sciences Two sciences can lay claim to the entire hydrosphere: hydrogeochemistry (the chemical structure of the hydrosphere) and hydrogeophysics (the physical structure of the hydrosphere). These sciences have a great future, they are still young.

However, when studying the entire hydrosphere, we must not forget that it is made up of countless water bodies: streams, rivers, clouds, lakes, seas, etc. When you encounter a small spring at the bottom of a hill, or a swamp in the forest, or a river, you must remember that these are particles of the great planetary shell - the hydrosphere, and the water that you drink or look at has, over its long history, been in the ocean, in the clouds, in the river, and underground.

Hydrology is a science that studies natural waters, their interaction with the atmosphere and lithosphere, as well as the phenomena and processes that occur in them (evaporation, freezing, etc.). The subject of study is all types of hydrosphere waters in oceans, seas, rivers, lakes, reservoirs, swamps, soil and groundwater. Hydrology deals with:

• · explores the water cycle in nature, the influence of human activity on it and the management of the regime of water bodies and the water regime of individual territories;
• · conducts analysis of hydrological elements for individual territories and the Earth as a whole;
• · provides an assessment and forecast of the state and rational use of water resources; uses methods used in geography, physics and other sciences.

The concept of the hydrosphere

Hydrosphere is the watery shell of the Earth. It includes all chemically unbound waters that are in liquid, solid (snow, ice) and gaseous states. 96.5% of waters come from the World Ocean, a little more than 1.7% from glaciers and permanent snow, 1.7% from groundwater and less than 0.01% from surface waters. Despite the variety of forms, the hydrosphere is united, which is determined by the unity of origin of all natural waters from the Earth’s mantle, their continuity and interconnection in the process of the water cycle in nature. The water cycle in nature is the continuous movement of water under the influence of solar energy (evaporation, water transport in the atmosphere) and gravity (seepage, runoff). The components of this cycle are evaporation from the surface of the World Ocean and land and the transfer of water vapor under the influence of solar energy; condensation of water vapor, precipitation, infiltration and runoff (surface and underground) into the ocean under the influence of gravity. Water on Earth plays the same role as blood in the human body. The planned pattern of the river network is very similar to the structure of the human circulatory system. Water constantly passes from the Water component to another, transferring, like blood in the body, various chemical substances from land to sea, from sea to land, from soil to plants, from plants to air, and so on ad infinitum. Without water, all life on Earth cannot exist. Water is the cradle of life. But water is also the main “sculptor” of the relief of the earth’s surface. And what, if not water, cleanses the earth of our own “products of vital activity”. Its sanitary, cleansing role has especially increased recently in areas of active economic activity of people.

The hydrosphere is the water shell of the Earth, including all chemically unbound water and held at the surface by gravity. The hydrosphere includes all natural waters of the Earth that participate in the global cycle of substances, including groundwater in the upper part of the earth’s crust, atmospheric moisture and water of living organisms (V.N. Mikhailov, A.D. Dobrovolsky, 1991 ). The upper boundary of the hydrosphere is drawn along the surface of the ocean, since water vapor in the atmosphere makes up a very small part of the hydrosphere. The lower boundary of the hydrosphere is drawn along the bottom of the ocean, in the lithosphere - along the boundary of the distribution of groundwater, i.e. at a depth of several hundred meters. Chemically bound water is water in minerals; it is not included in the hydrosphere.

Some scientists take a different point of view. S. V. Kalesnik (1955) classified only the waters of the World Ocean as the hydrosphere. According to F.N. Milkova (1990), the sphere itself is only the waters of the World Ocean and inland water bodies. Water vapor in the atmosphere should be called dispersed hydrosphere, and groundwater should be called buried hydrosphere. According to the author, all land waters, constituting about 6% (according to other data 4%) of the water of the hydrosphere, are a sphere of dispersion and are connected with the ocean only by moisture circulation.

Hydrology studies the hydrosphere - a science that studies the natural waters of the Earth and the processes occurring in them during interaction with the atmosphere, lithosphere, biosphere and taking into account the influence of economic activities. Hydrology is divided according to its focus and research methods into general hydrology, which studies the most general patterns of hydrological processes and phenomena; regional hydrology, which studies specific water bodies; engineering hydrology, which develops methods for calculating and predicting various hydrological characteristics. General hydrology according to the objects of study is divided into hydrology of the seas (physical oceanology), land hydrology and groundwater hydrology. Land hydrology, in turn, is divided according to the objects of study into the hydrology of rivers, lakes, swamps and glaciers.

The hydrosphere occupies 361 million km2.

The main mass of water is concentrated in the oceans - 1370.0 million km3, or 94.2% (97.2%, according to other data) of all water in the hydrosphere. Of these, about 35 thousand km3 are icebergs - a large reserve of clean water.

Groundwater takes second place - 60 million km3 (4.12%). About 4 million km3 circulates in the zone of active water exchange. According to scientists, in the 10-15-kilometer thickness of the lithosphere there is about 150 million km3 of water, which does not participate in moisture circulation, but represents a reserve of liquid water.

The third place in terms of water volume is occupied by polar glaciers, containing 24 million km3 of water. These waters also represent a reserve of fresh water, which is already being used in a number of countries. Polar glaciers contain about 90% of the fresh water reserves on Earth.

Land surface waters concentrate a small fraction of the planet's water. The volume of lake water is estimated at 278 thousand km3, the volume of rivers is only 1.2 thousand km3. The one-time supply of fresh water on Earth is about 32 million km3 - glaciers, fresh lakes, rivers and fresh groundwater (L.P. Shubaev, 1977).

The composition of the oldest rocks indicates the existence of the hydrosphere at the very beginning of the geological history of the Earth. The waters of the hydrosphere were formed simultaneously with gases of the atmosphere due to degassing of the mantle; the volume of the hydrosphere increased over time. Approximately 4.5 billion years ago (Catarchaean stage), the primary hydrosphere covered the entire Earth with a thin layer and its waters were mineralized. In the Proterozoic, a huge single landmass and a depression of the ancient Pacific Ocean were formed. In the Meso-Cenozoic, due to the formation of continents and large ocean basins, the hydrosphere acquired outlines close to modern ones. The volume of the hydrosphere continues to increase now at a rate of about 1 km3 per year. In this regard, it is expected that the volume of ocean water will increase by 6-7% over the next billion years (R. K. Kliege, 1982).

The hydrosphere loses water due to the evaporation of hydrogen into space and the removal of water by organisms in the photosynthesis reaction.