Water resources of the earth briefly. Groundwater feeds rivers and lakes

Which can be used in economic activities.

The total volume of static water resources in Russia is estimated at approximately 88.9 thousand km 3 of fresh water, of which a significant part is concentrated in groundwater, lakes and glaciers, the estimated share of which is 31%, 30% and 17%, respectively. The share of Russian static fresh water reserves in global resources is on average about 20% (excluding glaciers and groundwater). Depending on the type of water sources, this indicator varies from 0.1% (for glaciers) to 30% (for lakes).

Dynamic reserves of water resources in Russia amount to 4,258.6 km 3 per year (more than 10% of the world figure), which makes Russia the second country in the world in terms of gross volume of water resources after Brazil. At the same time, in terms of water resource availability, Russia ranks 28th in the world ().

Russia has significant water resources and annually uses no more than 2% of their dynamic reserves; At the same time, a number of regions are experiencing water shortages, which is mainly due to the uneven distribution of water resources throughout the country - the most developed areas of the European part of Russia, where more than 80% of the population is concentrated, account for no more than 10–15% of water resources.

Rivers

The river network of Russia is one of the most developed in the world: there are about 2.7 million rivers and streams on the territory of the state.

Over 90% of rivers belong to the basins of the Arctic and Pacific oceans; 10% - to the Atlantic Ocean basin (Baltic and Azov-Black Sea basins) and closed inland basins, the largest of which is the Caspian Sea basin. At the same time, about 87% of the population of Russia lives in the regions belonging to the basins of the Caspian Sea and the Atlantic Ocean and the bulk of the economic infrastructure, industrial production capacities and productive agricultural land are concentrated.

The length of the vast majority of Russian rivers does not exceed 100 km; a significant part of them are rivers less than 10 km long. They represent about 95% of the more than 8 million km of the Russian river network. Small rivers and streams are the main element of the channel network of drainage areas. Up to 44% of the Russian population lives in their basins, including almost 90% of the rural population.

The average long-term river flow of Russian rivers is 4258.6 km 3 per year, most of this volume is formed on the territory of the Russian Federation and only a small part comes from the territory of neighboring states. River flow is distributed unevenly across Russian regions - the average annual figure varies from 0.83 km 3 per year in the Republic of Crimea to 930.2 km 3 per year in the Krasnoyarsk Territory.

The average in Russia is 0.49 km/km 2 , while the spread of values of this indicator is uneven for different regions - from 0.02 km/km 2 in the Republic of Crimea to 6.75 km/km 2 in the Altai Republic.

A peculiarity of the structure of the Russian river network is the predominantly meridional direction of flow of most rivers.

The largest rivers in Russia

The question of which river is the largest in Russia can be answered in different ways - it all depends on what indicator is used to compare. The main indicators of rivers are basin area, length, average long-term flow. It is also possible to compare using indicators such as the density of the river network of the basin and others.

The largest water systems in Russia by basin area are the systems of the Ob, Yenisei, Lena, Amur and Volga; the total area of the basins of these rivers is over 11 million km 2 (including the foreign parts of the Ob, Yenisei, Amur and, slightly, Volga basins).

About 96% of all lake water reserves are concentrated in the eight largest lakes of Russia (excluding the Caspian Sea), of which 95.2% is in Lake Baikal.

The largest lakes in Russia

When determining which lake is the largest, it is important to determine the indicator by which the comparison will be made.The main indicators of lakes are surface area and basin area, average and maximum depths, water volume, salinity, altitude, etc.The undisputed leader in most indicators (area, volume, basin area) is the Caspian Sea.

The largest mirror area is in the Caspian Sea (390,000 km2), Baikal (31,500 km2), Lake Ladoga (18,300 km2), Lake Onega (9,720 km2) and Lake Taimyr (4,560 km2).

The largest lakes by drainage area are the Caspian (3,100,000 km2), Baikal (571,000 km2), Ladoga (282,700 km2), Uvs-Nur on the border of Mongolia and Russia (71,100 km2) and Vuoksa (68,500 km 2).

The deepest lake not only in Russia, but also in the world is Baikal (1642 m). Next come the Caspian Sea (1025 m), lakes Khantayskoe (420 m), Koltsevoe (369 m) and Tserik-Kol (368 m).

The deepest lakes are the Caspian (78,200 km 3), Baikal (23,615 km 3), Ladoga (838 km 3), Onega (295 km 3) and Khantayskoye (82 km 3).

The saltiest lake in Russia is Elton (water mineralization in the lake in autumn reaches 525‰, which is 1.5 times more than the mineralization of the Dead Sea) in the Volgograd region.

Lakes Baikal, Lake Teletskoye and Uvs-Nur are included in the UNESCO World Natural Heritage List. In 2008, Lake Baikal was recognized as one of the seven wonders of Russia.

Reservoirs

On the territory of Russia, there are about 2,700 reservoirs in operation with a capacity of over 1 million m 3 with a total useful volume of 342 km 3, and more than 90% of their number are reservoirs with a capacity of over 10 million m 3.

The main purposes of using reservoirs:

water supply;
Agriculture;
energy;
water transport;
fisheries;
timber rafting;
irrigation;
recreation (rest);
flood protection;
watering;
shipping.

The flow of rivers in the European part of Russia is most strongly regulated by reservoirs, where there is a shortage of water resources in certain periods. For example, the flow of the Ural River is regulated by 68%, the Don by 50%, and the Volga by 40% (reservoirs of the Volga-Kama cascade).

A significant share of regulated flow falls on the rivers of the Asian part of Russia, primarily in Eastern Siberia - the Krasnoyarsk Territory and the Irkutsk region (reservoirs of the Angara-Yenisei cascade), as well as the Amur region in the Far East.

The largest reservoirs in Russia

Due to the fact that the filling of reservoirs seriously depends on seasonal and annual factors, comparison is usually made based on the indicators achieved by the reservoir at (NFL).

The main tasks of reservoirs are the accumulation of water resources and the regulation of river flow, therefore, the important indicators by which the size of reservoirs are determined are full and. You can also compare reservoirs according to such parameters as the value of the FSL, the height of the dam, the surface area, the length of the coastline and others.

The largest reservoirs by full volume are located in the eastern regions of Russia: Bratskoye (169,300 million m3), Zeyaskoye (68,420 million m3), Irkutsk and Krasnoyarsk (63,000 million m3 each) and Ust-Ilimskoye (58,930 million m3). 3).

The largest reservoirs in Russia in terms of useful volume are Bratskoye (48,200 million m3), Kuibyshevskoye (34,600 million m3), Zeyaskoye (32,120 million m3), Irkutsk and Krasnoyarsk (31,500 million m3 each) - also almost all located in the east; The European part of Russia is represented by only one reservoir, the Kuibyshevsky reservoir, located in five regions of the Volga region.

The largest reservoirs by surface area: Irkutsk on the river. Angara (32,966 km 2), Kuibyshevskoye on the river. Volga (6,488 km 2), Bratskoe on the river. Angare (5,470 km 2), Rybinskoye (4,550 km 2) and Volgogradskoye (3,309 km 2) on the river. Volga.

Swamps

Swamps play an important role in the formation of the hydrological regime of rivers. Being a stable source of river nutrition, they regulate floods and floods, extending them in time and height, and within their tracts contribute to the natural purification of river waters from many pollutants. One of the important functions of swamps is carbon sequestration: swamps sequester carbon and thus reduce the concentration of carbon dioxide in the atmosphere, weakening the greenhouse effect; Every year, Russian swamps sequester about 16 million tons of carbon.

The total area of marshes in Russia is more than 1.5 million km 2, or 9% of the total area. Swamps are distributed unevenly across the country: the largest number of swamps are concentrated in the northwestern regions of the European part of Russia and in the central regions of the West Siberian Plain; further south the process of marsh formation weakens and almost stops.

The most swampy region is the Murmansk region - swamps make up 39.3% of the total area of the region. The least swamped areas are the Penza and Tula regions, the Republics of Kabardino-Balkaria, Karachay-Cherkessia, North Ossetia and Ingushetia, the city of Moscow (including new territories) - about 0.1%.

The areas of swamps range from several hectares to thousands of square kilometers. The swamps contain about 3,000 km 3 of static water reserves, and their total average annual flow is estimated at 1,000 km 3 /year.

An important element of swamps is peat - a unique combustible mineral of plant origin, which has... Russia's total peat reserves are about 235 billion tons, or 47% of world reserves.

The largest swamps in Russia

The largest swamp in Russia and one of the largest in the world is the Vasyugan swamp (52,000 km 2), located on the territory of four regions of the Russian Federation. – Salymo-Yugan swamp system (15,000 km 2), Upper Volga wetland complex (2,500 km 2), Selgon-Kharpinsky swamps (1,580 km 2) and Usinsk swamp (1,391 km 2).

The Vasyugan swamp is a candidate for inclusion in the list of UNESCO World Natural Heritage sites.

Glaciers

The total number of glaciers in the Russian Federation is over 8 thousand, the area of island and mountain glaciers is about 60 thousand km 2, water reserves are estimated at 13.6 thousand km 3, which makes glaciers one of the largest accumulators of water resources in the country.

In addition, large reserves of fresh water are preserved in the Arctic ice, but their volumes are constantly decreasing and, according to recent estimates, this strategic fresh water reserve may disappear by 2030.

Most of Russia's glaciers are represented by the ice sheets of the islands and archipelagos of the Arctic Ocean - about 99% of Russia's glacial water resources are concentrated in them. Mountain glaciers account for slightly more than 1% of the glacial water supply.

The share of glacial feeding in the total flow of rivers originating from glaciers reaches 50% of the annual volume; The average long-term glacial runoff feeding the rivers is estimated at 110 km 3 /year.

Glacial systems of Russia

In terms of glaciation area, the largest are the mountain glacial systems of Kamchatka (905 km 2), the Caucasus (853.6 km 2), Altai (820 km 2), the Koryak Highlands (303.5 km 2) and the Suntar-Khayata ridge (201.6 km 2).

The largest reserves of fresh water are contained in the mountain glacial systems of the Caucasus and Kamchatka (50 km 3 each), Altai (35 km 3), Eastern Sayan (31.8 km 3) and the Suntar-Khayata ridge (12 km 3).

The groundwater

Groundwater accounts for a significant portion of fresh water reserves in Russia. In conditions of increasing deterioration in the quality of surface waters, fresh groundwater is often the only source of providing the population with high-quality drinking water, protected from pollution.

Natural groundwater reserves in Russia are about 28 thousand km 3 ; forecast resources, according to state monitoring of the state of the subsoil, are about 869,055 thousand m 3 /day - from approximately 1,330 thousand m 3 /day in the Crimean to 250,902 thousand m 3 /day in the Siberian Federal District.

The average provision of predicted groundwater resources in Russia is 6 m 3 /day per person.

HYDRAULIC SYSTEMS AND STRUCTURES

Hydraulic structures (HTS) are structures for the use of water resources, as well as for combating the negative effects of water. Dams, canals, dikes, shipping locks, tunnels, etc. GTS make up a significant part of the water management complex of the Russian Federation.

In Russia there are about 65 thousand hydraulic structures of water management, fuel and energy complexes and transport infrastructure.

To redistribute river flow from areas with excess river flow to areas with deficit, 37 large water management systems were created (the volume of transferred flow is about 17 billion m 3 /year); To regulate river flow, about 30 thousand reservoirs and ponds with a total capacity of more than 800 billion m 3 were built; To protect settlements, economic facilities and agricultural lands, over 10 thousand km of protective water barrier dams and shafts were built.

The reclamation and water management complex of federal property includes more than 60 thousand various hydraulic structures, including over 230 reservoirs, more than 2 thousand regulating waterworks, about 50 thousand km of water supply and discharge canals, over 3 thousand km of protective shafts and dams .

The transport hydroelectric complexes include more than 300 navigable hydraulic structures located on inland waterways and are federally owned.

Hydraulic structures of Russia are under the jurisdiction of the Federal Agency for Water Resources, the Ministry of Agriculture of the Russian Federation, the Ministry of Transport of the Russian Federation, and the constituent entities of the Russian Federation. Some of the hydraulic structures are privately owned, over 6 thousand are ownerless.

Channels

Artificial riverbeds and canals are an important part of the water system of the Russian Federation. The main tasks of canals are flow redistribution, navigation, irrigation and others.

Almost all operating shipping canals in Russia are located in the European part and, with some exceptions, are part of the Unified Deep-Water System of the European part of the country. Some canals have historically been combined into waterways, for example, the Volga-Baltic and North Dvina, consisting of natural (rivers and lakes) and artificial (canals and reservoirs) waterways. There are also sea canals created to reduce the length of sea roads, reduce the risks and dangers of navigation, and increase the passability of water bodies connected to the seas.

The bulk of economic (reclamation) canals with a total length of over 50 thousand km are concentrated in the Southern and North Caucasus Federal Districts, and to a lesser extent in the Central, Volga and southern Siberian Federal Districts. The total area of reclaimed lands in Russia is 89 thousand km 2. Irrigation is of great importance for Russian agriculture, since arable land is located mainly in the steppe and forest-steppe zones, where agricultural yields fluctuate sharply from year to year depending on weather conditions and only 35% of arable land is in favorable conditions for moisture supply.

The largest channels in Russia

The largest waterways in Russia: the Volga-Baltic waterway (861 km), which includes, in addition to natural routes, the Belozersky, Onega bypass, Vytegorsky and Ladoga canals; White Sea-Baltic Canal (227 km), Volga-Caspian Canal (188 km), Moscow Canal (128 km), North Dvina Waterway (127 km), including Toporninsky, Kuzminsky, Kishemsky and Vazerinsky canals; Volga-Don Canal (101 km).

The longest economic canals in Russia that abstract water directly from water bodies (rivers, lakes, reservoirs): North Crimean Canal - , - a legal act regulating relations in the field of water use.

In accordance with Article 2 of the Water Code, the water legislation of Russia consists of the Code itself, other federal laws and laws of the constituent entities of the Russian Federation adopted in accordance with them, as well as by-laws adopted by executive authorities.

Water legislation (laws and regulations issued in accordance with them) is based on the following principles:

Part of the Russian legal system in the field of use and protection of water bodies are international treaties of Russia and ratified international conventions, such as the Convention on Wetlands (Ramsar, 1971) and the UN Economic Commission for Europe Convention on the Protection and Use of Transboundary Watercourses and International Lakes (Helsinki , 1992).

Water management

The central link in the field of use and protection of water resources is the Ministry of Natural Resources and Ecology of the Russian Federation (Ministry of Natural Resources of Russia), which exercises the authority to develop state policy and legal regulation in the field of water relations in Russia.

Russia's water resources are managed at the federal level by the Federal Agency for Water Resources (Rosvodresursy), which is part of the Russian Ministry of Natural Resources.

The powers of Rosvodresurs to provide public services and manage federal property in the regions are exercised by the agency's territorial divisions - basin water departments (BWU), as well as 51 subordinate institutions. Currently, there are 14 commercial banks operating in Russia, the structure of which includes departments in all regions of the Russian Federation. The exception is the regions of the Crimean Federal District - in accordance with the agreements signed in July - August 2014, part of the powers of Rosvodresursov was transferred to the relevant structures of the Council of Ministers of the Republic of Crimea and the Government of Sevastopol.

Management of regionally owned water resources is carried out by the relevant structures of regional administrations.

Management of federal facilities of the reclamation complex is under the jurisdiction of the Ministry of Agriculture of the Russian Federation (Department of Reclamation), water bodies of transport infrastructure - the Ministry of Transport of the Russian Federation (Federal Agency of Sea and River Transport).

State accounting and monitoring of water resources is carried out by Rosvodresursy; for maintaining the State Water Register - with the participation of the Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet) and the Federal Agency for Subsoil Use (Rosnedra); for maintaining the Russian Register of Hydraulic Structures - with the participation of the Federal Service for Environmental, Technological and Nuclear Supervision (Rostekhnadzor) and the Federal Service for Supervision of Transport (Rostransnadzor).

Supervision of compliance with legislation regarding the use and protection of water bodies is carried out by the Federal Service for Natural Resources Management (Rosprirodnadzor), and of hydraulic structures - by Rostechnadzor and Rostransnadzor.

According to the Water Code of the Russian Federation, the main unit of the management structure in the field of use and protection of water bodies is basin districts, however, today the existing structure of Rosvodresurs is organized on an administrative-territorial principle and in many ways does not coincide with the boundaries of basin districts.

Public policy

The basic principles of state policy in the field of use and protection of water bodies are enshrined in the Water Strategy of the Russian Federation until 2020 and include three key areas:

guaranteed provision of water resources to the population and economic sectors;
protection and restoration of water bodies;
ensuring protection from the negative effects of water.

As part of the implementation of the state water policy, the federal target program “Development of the water management complex of the Russian Federation in 2012–2020” (Federal Target Program “Water of Russia”) was adopted in 2012. The federal target program “Clean Water” for 2011–2017, the federal target program “Development of reclamation of agricultural lands in Russia for 2014–2020”, and target programs in Russian regions were also adopted.

Water resources are the reserves of surface and groundwater located in water bodies that are used or can be used.
Water occupies 71% of the Earth's surface. 97% of water resources are salt water and only 3% are fresh water. Water is also found in soil and rocks, plants and animals. A large amount of water is constantly in the atmosphere.
Water is one of the most valuable natural resources. One of the main properties of water is its irreplaceability. In itself, it has no nutritional value, but it plays an exceptional role in metabolic processes that form the basis of the life activity of all life on Earth, determining its productivity.
A person's daily need for water under normal conditions is about 2.5 liters.
Water has a high heat capacity. Absorbing a huge amount of thermal cosmic and intraterrestrial energy and slowly releasing it, water serves as a regulator and stabilizer of climate processes, softening strong temperature fluctuations. Evaporating from water surfaces, it turns into a gaseous state and is transported by air currents to various regions of the planet, where it falls in the form of precipitation. Glaciers have a special place in the water cycle, since they retain moisture in a solid state for a very long time (thousands of years). Scientists have concluded that the water balance on Earth is almost constant.
For many millions of years, water activates soil formation processes. It greatly cleanses the environment by dissolving and removing contaminants.
A lack of water can slow down economic activity and reduce production efficiency. In the modern world, water has acquired independent importance as an industrial raw material, often scarce and very expensive. Water is an essential component of almost all technological processes. Water of special purity is needed in medicine, food production, nuclear technology, semiconductor production, etc. Huge amounts of water are spent on people's domestic needs, especially in big cities.
The predominant part of the earth's waters is concentrated in the World Ocean. This is a rich storehouse of mineral raw materials. For every 1 kg of ocean water there are 35 g of salts. Sea water contains more than 80 elements of the D.I. Periodic Table. Mendeleev, the most important of which for economic purposes are tungsten, bismuth, gold, cobalt, lithium, magnesium, copper, molybdenum, nickel, tin, lead, silver, uranium.
The world ocean is the main link in the water cycle in nature. It releases most of the evaporated moisture into the atmosphere. Absorbing a huge amount of thermal energy and slowly releasing it, ocean waters serve as a regulator of climate processes on a global scale. The heat of the oceans and seas is spent on maintaining the vital activity of marine organisms, which provide food, oxygen, medicines, fertilizers, and luxury goods to a significant part of the planet's population.
Aquatic organisms inhabiting the surface layer of the World Ocean provide the return of a significant part of the planet’s free oxygen to the atmosphere. This is extremely important, since motor vehicles and oxygen-intensive metallurgical and chemical production often consume more oxygen than the nature of individual regions can compensate.
Fresh waters on land include glacial, underground, river, lake, and swamp waters. In recent years, good quality drinking water has become a renewable resource of strategic importance. Its shortage is explained by a significant deterioration in the general environmental situation around the sources of this resource, as well as tightening worldwide requirements for the quality of consumed water, both for drinking and for high-tech industries.
The bulk of fresh water reserves on land are concentrated in the ice sheets of Antarctica and the Arctic. They represent a huge reservoir of fresh water on the planet (68% of all fresh water). These reserves are preserved for many millennia.
The chemical composition of groundwater is very different: from fresh to water with a high concentration of minerals.
Fresh surface waters have a significant ability for self-purification, which is provided by the Sun, air, micro-

roorganisms and oxygen dissolved in water. However, fresh water is becoming a major shortage on the planet.
Swamps contain 4 times more water than the world's rivers; 95% of swamp water is located in peat layers.
The atmosphere contains water mainly in the form of water vapor. Its bulk (90%) is concentrated in the lower layers of the atmosphere, up to a height of 10 km.
Fresh water is distributed unevenly across the Earth. The problem of supplying the population with drinking water is very acute and has become increasingly worse in recent years. About 60% of the Earth's surface is made up of zones where fresh water is either absent, severely deficient, or of poor quality. Approximately half of humanity experiences a shortage of drinking water.
Fresh surface waters (rivers, lakes, swamps, soil and groundwater) are subject to the most severe pollution. Most often, sources of pollution are insufficiently treated or not treated at all discharges from production facilities (including hazardous ones), discharges from large cities, and runoff from landfills.
Environmental pollution in the Volga basin is 3-5 times higher than the national average. Not a single city on the Volga is provided with
quality drinking water. There are many environmentally hazardous industries and enterprises in the basin without treatment facilities.
The exploitable reserves of explored groundwater deposits in Russia are estimated at approximately 30 km/year. The degree of development of these reserves currently averages just over 30%.

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Water resources and their importance

water natural economic

If you look at our planet from space, the Earth appears as a blue ball completely covered with water. Water covers the earth's surface, forming the World Ocean and the endless icy deserts of the polar regions. The watery shell of our planet is called the hydrosphere.

Water resources mean the entire variety of water suitable for economic use. Among natural resources, water resources occupy one of the most important places.

The main purpose of water as a natural resource is to support the life of all living things - plants, animals and humans.

Water sources play an important role in the transformation of our planet. From time immemorial, people have settled near reservoirs and water sources. Water is also the creator of natural landscapes and serves as one of the important means of communication.

Water is the most important factor in climate formation.

A special role belongs to inland reservoirs and watercourses, which are transport arteries and sources of food resources.

Types of water resources

The water resources of our planet are the reserves of all water. Water is one of the most common and most unique compounds on Earth, as it is present in three states at once: liquid, solid and gaseous. Based on this, the main types of water resources can be identified.

There are also potential water resources such as:

* Glaciers and snowfields (frozen water from glaciers in Antarctica, the Arctic and highlands).

* Atmospheric vapors.

But people have not yet learned to use these resources.

Use of water.

When we talk about the Earth's water resources, we usually mean the planet's supply of fresh water.

Water is the most important component of human life. A special place in the use of water resources is occupied by water consumption for the needs of the population.

According to statistics, most water resources are used in agriculture (about 66% of all fresh water reserves).

Don't forget about fisheries. Breeding marine and freshwater fish plays an important role in the economy of many countries.

Water bodies also serve as a favorite vacation spot for people. Who among us doesn’t like to relax by the sea, barbecue on the river bank or swim in the lake? In the world, about 90% of all recreational facilities are located near bodies of water.

Based on all this, the question arises: How much water is there in the modern biosphere? Is the supply of fresh water inexhaustible?

It turns out that the entire volume of the hydrosphere is approximately 1.4 billion cubic meters. Of this, 94% comes from the salty waters of the seas and oceans. And the remaining 6% is distributed between groundwater, rivers, lakes, streams, and glaciers.

Currently, the availability of water per person per day varies greatly in different countries of the world.

In order to find out how each of us can help save water, I looked at water consumption for household needs, using the example of residents of Russia, and this is what we learned.

Water consumption of Russian residents for sanitary and domestic needs

Thus, the higher the degree of home improvement, the greater the water consumption.

The growth of cities and population, the development of production and agriculture - these factors have led to a shortage of fresh water for humanity. In a number of countries with developed economies, the threat of water shortages is brewing. The shortage of fresh water on earth is growing quite quickly. The share of polluted water resources is growing every year.

In recent years, environmentalists in all countries have been sounding the alarm. Due to man's careless attitude towards water resources, great changes are occurring on Earth that are harmful to human health and lead to the death of animals and plants.

I monitored water consumption in our school, at home and in our neighbors. And here's what it turned out: in everyday life, water is not used sparingly. A huge amount of water is wasted unnecessarily. For example: a leaking washbasin (or faucet), leaking heating system pipes, unfinished water in a glass…. etc.

We don’t think at all about the fact that there may be a shortage of fresh water.

As a result of my research, I came to the conclusion that each of us, being in our home, at work or at school, can at least slightly help preserve fresh water supplies on our planet.

Thus, my hypothesis turned out to be correct. To achieve my goal - to develop a careful attitude towards water, based on the results of my work, I compiled a reminder that will help save water.

Water is a wonderful gift of nature. We are used to it being all around us - in raindrops, snowdrifts, in rivers and lakes, in swamps, glaciers, gushing out in cold springs from the slopes or at the bottom of the river. Water is needed for all living things, as well as in inanimate nature.

And as it turns out, fresh water supplies are not endless.

It is mistakenly believed that humanity has inexhaustible reserves of fresh water at its disposal and that they are sufficient for all needs. This is a deep misconception.

The problem of fresh water shortage arose for the following main reasons:

· intensive increase in demand for water due to the rapid growth of the planet's population and the development of industries that require huge amounts of water resources.

· loss of fresh water due to reduced water flow in rivers.

· pollution of water bodies with industrial and domestic wastewater.

The world needs sustainable water management practices, but we are not moving fast enough in the right direction. Humanity is too slow to understand the scale of the danger created by a careless attitude towards the environment.

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...

World water resources - the big picture

With the Earth's water resources, the overall picture is:

overall volume water resources is 1,390,000,000 cubic meters. km;
less than 3% of the earth's water resources are fresh water;
0.3% of available fresh water is the water of rivers, lakes...ground and underground.

Parts of the hydrosphere

Stationary water resources of the world according to M. I. Lvovich:

World Ocean:
- Volume of water, thousand km 3 - 1,370,000;
- Water exchange activity, number of years - 3,000.
The groundwater :
- Volume of water, thousand km 3 - ~ 60,000;
Groundwater... including zones of active exchange:
- Volume of water, thousand km 3 - ~ 4,000;
- Water exchange activity, number of years - ~ 330.
Glaciers:
- Volume of water, thousand km 3 - 24,000;
- Water exchange activity, number of years - 8,600.
Lakes:
- Volume of water, thousand km 3 - 230;
- Water exchange activity, number of years - 10.
Soil moisture:
- Volume of water, thousand km 3 - 82;
- Water exchange activity, number of years - 1.
River (channel) waters:
- Volume of water, thousand km 3 - 1.2;
- Water exchange activity, number of years - 0.032.
Atmospheric vapors:
- Volume of water, thousand km 3 - 14;
- Water exchange activity, number of years - 0.027.

Water exists in natural conditions in three basic states - ice, liquid and steam, due to which there is a constant circulation and redistribution of water resources - the water cycle in nature (the continuous movement of water in the hydrosphere, atmosphere, lithosphere). Under the influence of heat, liquid water evaporates, the steam, in turn, rises into the atmosphere, where it condenses and returns to the earth in the form of precipitation - rain, snow, dew... part of the water accumulates in glaciers, which in turn return part of the water again to a liquid state.

It should be noted that 98% of all fresh liquid water comes from groundwater.

Water resources and ecology

Let us note an important fact - the total amount of water in nature remains unchanged. However, it is necessary to understand that the active activities of mankind lead to environmental deterioration and upset the balance of the planet’s ecosystems, and this in turn significantly reduces the quantity and availability of clean drinking water that people need for a healthy and quality life.

In some regions of the planet, intensive human economic activity is already leading to a noticeable shortage of fresh water. This is especially noticeable in those regions that previously experienced a lack of fresh water due to natural causes.

Maintaining a system that guarantees a stable replenishment of clean drinking water on our planet is an important condition for the development of modern civilization.

And finally, some more background information.

River flow by parts of the world

Europe:
- Volume of annual runoff, km 3 - 2,950;
- Drain layer, mm - 300.
Asia:
- Volume of annual runoff, km 3 - 12,860;
- Drain layer, mm - 286.
Africa:
- Volume of annual runoff, km 3 - 4,220;
- Drain layer, mm - 139.
North and Central America:
- Volume of annual runoff, km 3 - 5,400;
- Drain layer, mm - 265.
South America:
- Volume of annual runoff, km 3 - 8,000;
- Drain layer, mm - 445.
Australia, including Tasmania, New Guinea and New Zealand:
- Volume of annual runoff, km 3 - 1,920;
- Drain layer, mm - 218.
Antarctica and Greenland:
- Volume of annual runoff, km 3 - 2,800;
- Drain layer, mm - 2,800.
All land:
- Volume of annual runoff, km 3 - 38,150;
- Drain layer, mm - 252.

Balance assessment of water resources. Sources of Water Resources

Total river flow:
- All land, km 3 - 38,150;
- All land, mm - 260.
Underground drain:
- All land, km 3 - 12,000*;
- All land, mm - 81.
Evaporation:
- All land, km 3 - 72,400;
- All land, mm - 470.
Precipitation:
- All land, km 3 - 109,400;
- All land, mm - 730.
- All land, km 3 - 26,150;
- All land, mm - 179.
Surface (flood) runoff:
- All land, km 3 - 82,250;
- All land, mm - 551.

The content of the article

WATER RESOURCES, waters in liquid, solid and gaseous states and their distribution on Earth. They are found in natural bodies of water on the surface (oceans, rivers, lakes and swamps); in the subsoil (groundwater); in all plants and animals; as well as in artificial reservoirs (reservoirs, canals, etc.).

The water cycle in nature.

Although the world's total supply of water is constant, it is constantly being redistributed and is therefore a renewable resource. The water cycle occurs under the influence of solar radiation, which stimulates the evaporation of water. In this case, the minerals dissolved in it precipitate. Water vapor rises into the atmosphere, where it condenses, and thanks to gravity, the water returns to the earth in the form of precipitation - rain or snow. Most precipitation falls over the ocean and only less than 25% falls over land. About 2/3 of this precipitation enters the atmosphere as a result of evaporation and transpiration, and only 1/3 flows into rivers and seeps into the ground.

Gravity promotes the redistribution of liquid moisture from higher to lower areas, both on the earth's surface and under it. Water, initially set in motion by solar energy, moves in the seas and oceans in the form of ocean currents, and in the air in clouds.

Geographical distribution of precipitation.

The volume of natural renewal of water reserves due to precipitation varies depending on the geographical location and size of parts of the world. For example, South America receives almost three times as much annual precipitation as Australia, and almost twice as much as North America, Africa, Asia, and Europe (listed in order of decreasing annual precipitation). Some of this moisture returns to the atmosphere as a result of evaporation and transpiration by plants: in Australia this value reaches 87%, and in Europe and North America - only 60%. The rest of the precipitation flows over the earth's surface and eventually reaches the ocean with river runoff.

Within continents, precipitation also varies greatly from place to place. For example, in Africa, in Sierra Leone, Guinea and Cote d'Ivoire, more than 2000 mm of precipitation falls annually, in most of central Africa - from 1000 to 2000 mm, but in some northern regions (Sahara and Sahel deserts) the amount precipitation is only 500–1000 mm, and in southern Botswana (including the Kalahari Desert) and Namibia - less than 500 mm.

Eastern India, Burma and parts of Southeast Asia receive more than 2000 mm of rainfall per year, and most of the rest of India and China receive between 1000 and 2000 mm, with northern China receiving only 500–1000 mm. Northwestern India (including the Thar Desert), Mongolia (including the Gobi Desert), Pakistan, Afghanistan and much of the Middle East receive less than 500 mm of annual rainfall.

In South America, annual precipitation in Venezuela, Guyana and Brazil exceeds 2000 mm, most of the eastern regions of this continent receive 1000–2000 mm, but Peru and parts of Bolivia and Argentina receive only 500–1000 mm, and Chile receives less than 500 mm. In some areas of Central America located to the north, over 2000 mm of precipitation falls per year, in the southeastern regions of the USA - from 1000 to 2000 mm, and in some areas of Mexico, in the northeast and Midwest of the USA, in eastern Canada - 500–1000 mm mm, while in central Canada and the western United States it is less than 500 mm.

In the far north of Australia, annual rainfall is 1000–2000 mm, in some other northern areas it ranges from 500 to 1000 mm, but most of the mainland and especially its central regions receive less than 500 mm.

Much of the former USSR also receives less than 500 mm of precipitation per year.

Time cycles of water availability.

At any point on the globe, river flow experiences daily and seasonal fluctuations, and also changes at intervals of several years. These variations are often repeated in a certain sequence, i.e. are cyclical. For example, water flows in rivers whose banks are covered with dense vegetation tend to be higher at night. This is because from dawn to dusk vegetation uses groundwater for transpiration, resulting in a gradual reduction in river flow, but its volume increases again at night when transpiration stops.

Seasonal cycles of water availability depend on the distribution of precipitation throughout the year. For example, in the Western United States, snow melts together in the spring. India receives little rainfall in winter, but heavy monsoon rains begin in midsummer. Although the average annual river flow is almost constant over a number of years, it is extremely high or extremely low once every 11–13 years. This may be due to the cyclical nature of solar activity. Information on the cyclicity of precipitation and river flow is used in forecasting water availability and frequency of droughts, as well as in planning water protection activities.

WATER SOURCES

The main source of fresh water is precipitation, but two other sources can also be used for consumer needs: groundwater and surface water.

Underground springs.

Approximately 37.5 million km 3, or 98% of all fresh water in liquid form, is groundwater, and approx. 50% of them lie at depths of no more than 800 m. However, the volume of available groundwater is determined by the properties of the aquifers and the power of the pumps pumping out the water. Groundwater reserves in the Sahara are estimated at approximately 625 thousand km 3 . Under modern conditions, they are not replenished by surface fresh waters, but are depleted when pumped out. Some of the deepest groundwater is never included in the general water cycle, and only in areas of active volcanism does such water erupt in the form of steam. However, a significant mass of groundwater still penetrates the earth's surface: under the influence of gravity, these waters, moving along waterproof, inclined rock layers, emerge at the foot of the slopes in the form of springs and streams. In addition, they are pumped out by pumps, and also extracted by plant roots and then enter the atmosphere through the process of transpiration.

The water table represents the upper limit of available groundwater. If there are slopes, the groundwater table intersects with the earth's surface, and a source is formed. If groundwater is under high hydrostatic pressure, then artesian springs are formed at the places where they reach the surface. With the advent of powerful pumps and the development of modern drilling technology, the extraction of groundwater has become easier. Pumps are used to supply water to shallow wells installed on aquifers. However, in wells drilled to greater depths, to the level of pressure artesian waters, the latter rise and saturate the overlying groundwater, and sometimes come to the surface. Groundwater moves slowly, at a speed of several meters per day or even per year. They are usually found in porous pebbly or sandy horizons or relatively impervious shale formations, and only rarely are they concentrated in underground cavities or underground streams. To correctly select the location for drilling a well, information about the geological structure of the area is usually required.

In some parts of the world, increasing consumption of groundwater is having serious consequences. Pumping a large volume of groundwater, incomparably exceeding its natural replenishment, leads to a lack of moisture, and lowering the level of this water requires greater costs for expensive electricity used to extract it. In places where the aquifer is depleted, the earth's surface begins to subsidence, and there it becomes more difficult to restore water resources naturally.

In coastal areas, excessive groundwater withdrawal leads to the replacement of fresh water in the aquifer with seawater and saline water, thereby degrading local freshwater sources.

The gradual deterioration of groundwater quality as a result of salt accumulation can have even more dangerous consequences. Sources of salts can be both natural (for example, the dissolution and removal of minerals from soils) and anthropogenic (fertilization or excessive watering with water with a high salt content). Rivers fed by mountain glaciers usually contain less than 1 g/l of dissolved salts, but the mineralization of water in other rivers reaches 9 g/l due to the fact that they drain areas composed of salt-bearing rocks over a long distance.

Indiscriminate release or disposal of toxic chemicals causes them to leak into aquifers that provide drinking or irrigation water. In some cases, only a few years or decades are enough for harmful chemicals to enter groundwater and accumulate there in noticeable quantities. However, once the aquifer has been contaminated, it will take 200 to 10,000 years to naturally cleanse itself.

Surface sources.

Only 0.01% of the total volume of fresh water in liquid state is concentrated in rivers and streams and 1.47% in lakes. To store water and constantly provide it to consumers, as well as to prevent unwanted floods and generate electricity, dams have been built on many rivers. The Amazon in South America, the Congo (Zaire) in Africa, the Ganges with the Brahmaputra in southern Asia, the Yangtze in China, the Yenisei in Russia and the Mississippi and Missouri in the USA have the highest average water flows, and therefore the greatest energy potential.

Natural freshwater lakes holding approx. 125 thousand km 3 of water, along with rivers and artificial reservoirs, are an important source of drinking water for people and animals. They are also used for irrigation of agricultural lands, navigation, recreation, fishing and, unfortunately, for the discharge of domestic and industrial wastewater. Sometimes, due to gradual filling with sediment or salinization, lakes dry up, but in the process of evolution of the hydrosphere, new lakes form in some places.

The water level of even “healthy” lakes can decrease throughout the year as a result of water runoff through the rivers and streams flowing from them, due to water seeping into the ground and its evaporation. Restoration of their levels usually occurs due to precipitation and the influx of fresh water from rivers and streams flowing into them, as well as from springs. However, as a result of evaporation, salts coming with river runoff accumulate. Therefore, after thousands of years, some lakes can become very salty and unsuitable for many living organisms.

USING WATER

Water consumption.

Water consumption is growing rapidly everywhere, but not only due to an increase in population, but also due to urbanization, industrialization and especially the development of agricultural production, in particular irrigated agriculture. By 2000, daily global water consumption reached 26,540 billion liters, or 4,280 liters per person. 72% of this volume is spent on irrigation, and 17.5% on industrial needs. About 69% of irrigation water has been lost forever.

Water quality,

used for various purposes, is determined depending on the quantitative and qualitative content of dissolved salts (i.e. its mineralization), as well as organic substances; solid suspensions (silt, sand); toxic chemicals and pathogenic microorganisms (bacteria and viruses); smell and temperature. Typically, fresh water contains less than 1 g/l of dissolved salts, brackish water contains 1–10 g/l, and salt water contains 10–100 g/l. Water with a high salt content is called brine, or brine.

Obviously, for navigation purposes, water quality (salinity of sea water reaches 35 g/l, or 35‰) is not significant. Many species of fish have adapted to life in salt water, but others live only in fresh water. Some migratory fish (such as salmon) begin and complete their life cycles in inland fresh waters, but spend most of their lives in the ocean. Some fish (like trout) need cold water, while others (like perch) prefer warm water.

Most industries use fresh water. But if such water is in short supply, then some technological processes, such as cooling, may proceed based on the use of low-quality water. Water for domestic purposes must be of high quality, but not absolutely pure, since such water is too expensive to produce, and the lack of dissolved salts makes it tasteless. In some areas of the world, people are still forced to use low-quality muddy water from open reservoirs and springs for their daily needs. However, in industrialized countries, all cities are now supplied with piped, filtered and specially treated water that meets at least minimum consumer standards, especially with regard to potability.

An important characteristic of water quality is its hardness or softness. Water is considered hard if the content of calcium and magnesium carbonates exceeds 12 mg/l. These salts are bound by some components of detergents, and thus foam formation is impaired; an insoluble residue remains on washed items, giving them a matte gray tint. Calcium carbonate from hard water forms scale (lime crust) in kettles and boilers, which reduces their service life and the thermal conductivity of the walls. The water is softened by adding sodium salts that replace calcium and magnesium. In soft water (containing less than 6 mg/l of calcium and magnesium carbonates), soap foams well and is more suitable for washing and washing. Such water should not be used for irrigation, since excess sodium is harmful to many plants and can disrupt the loose, clumpy structure of soils.

Although elevated concentrations of trace elements are harmful and even poisonous, small amounts of them can have beneficial effects on human health. An example is water fluoridation to prevent caries.

Reuse of water.

Used water is not always completely lost; some or even all of it can be returned to the cycle and reused. For example, water from a bath or shower passes through sewer pipes to city wastewater treatment plants, where it is treated and then reused. Typically, more than 70% of urban runoff returns to rivers or underground aquifers. Unfortunately, in many large coastal cities, municipal and industrial wastewater is simply dumped into the ocean and not recycled. Although this method eliminates the cost of cleaning them and returning them to circulation, there is a loss of potentially usable water and pollution of marine areas.

In irrigated agriculture, crops consume huge amounts of water, sucking it up with their roots and irreversibly losing up to 99% in the process of transpiration. However, when irrigating, farmers typically use more water than is needed for their crops. Part of it flows to the periphery of the field and returns to the irrigation network, and the rest seeps into the soil, replenishing groundwater reserves, which can be pumped out using pumps.

Use of water in agriculture.

Agriculture is the largest consumer of water. In Egypt, where there is almost no rain, all agriculture is based on irrigation, while in Great Britain almost all crops are provided with moisture from precipitation. In the United States, 10% of agricultural land is irrigated, mostly in the west of the country. A significant portion of agricultural land is artificially irrigated in the following Asian countries: China (68%), Japan (57%), Iraq (53%), Iran (45%), Saudi Arabia (43%), Pakistan (42%), Israel ( 38%), India and Indonesia (27% each), Thailand (25%), Syria (16%), Philippines (12%) and Vietnam (10%). In Africa, besides Egypt, a significant share of irrigated land is in Sudan (22%), Swaziland (20%) and Somalia (17%), and in America - in Guyana (62%), Chile (46%), Mexico (22% ) and in Cuba (18%). In Europe, irrigated agriculture is developed in Greece (15%), France (12%), Spain and Italy (11% each). In Australia, approx. 9% agricultural land and approx. 5% – in the former USSR.

Water consumption by different crops.

To obtain high yields, a lot of water is required: for example, growing 1 kg of cherries requires 3000 liters of water, rice - 2400 liters, corn on the cob and wheat - 1000 liters, green beans - 800 liters, grapes - 590 liters, spinach - 510 l, potatoes - 200 l and onions - 130 l. The approximate amount of water spent just on growing (and not on processing or preparing) food crops consumed daily by one person in Western countries is approx. 760 l, for lunch (lunch) 5300 l and for dinner - 10,600 l, which is a total of 16,600 l per day.

In agriculture, water is used not only to irrigate crops, but also to replenish groundwater reserves (to prevent the groundwater level from dropping too quickly); for washing out (or leaching) salts accumulated in the soil to a depth below the root zone of cultivated crops; for spraying against pests and diseases; frost protection; application of fertilizers; reducing air and soil temperatures in summer; for caring for livestock; evacuation of treated wastewater used for irrigation (mainly grain crops); and processing of harvested crops.

Food industry.

Processing of different food crops requires varying amounts of water depending on the product, production technology and the availability of sufficient quality water. In the USA, from 2000 to 4000 liters of water are consumed to produce 1 ton of bread, and in Europe - only 1000 liters and only 600 liters in some other countries. Canning fruits and vegetables requires 10,000 to 50,000 liters of water per ton in Canada, but only 4,000 to 1,500 in Israel, where water is a great scarcity. The “champion” in terms of water consumption is lima beans, 70,000 liters of water are consumed in the USA to preserve 1 ton of them. Processing 1 ton of sugar beet requires 1,800 liters of water in Israel, 11,000 liters in France and 15,000 liters in the UK. Processing 1 ton of milk requires from 2000 to 5000 liters of water, and to produce 1000 liters of beer in the UK - 6000 liters, and in Canada - 20,000 liters.

Industrial water consumption.

The pulp and paper industry is one of the most water-intensive industries due to the huge volume of raw materials processed. The production of each ton of pulp and paper requires an average of 150,000 liters of water in France and 236,000 liters in the USA. The newsprint production process in Taiwan and Canada uses approx. 190,000 liters of water per 1 ton of product, while the production of a ton of high-quality paper in Sweden requires 1 million liters of water.

Fuel industry.

To produce 1,000 liters of high-quality aviation gasoline, 25,000 liters of water are required, and motor gasoline requires two-thirds less.

Textile industry

requires a lot of water for soaking raw materials, cleaning and washing them, bleaching, dyeing and finishing fabrics and for other technological processes. To produce each ton of cotton fabric, from 10,000 to 250,000 liters of water are required, for woolen fabric - up to 400,000 liters. The production of synthetic fabrics requires significantly more water - up to 2 million liters per 1 ton of product.

Metallurgical industry.

In South Africa, when mining 1 ton of gold ore, 1000 liters of water are consumed, in the USA, when mining 1 ton of iron ore, 4000 liters and 1 ton of bauxite - 12,000 liters. Iron and steel production in the US requires approximately 86,000 L of water for every ton of production, but up to 4,000 L of this is deadweight loss (mainly evaporation), and therefore approximately 82,000 L of water can be reused. Water consumption in the iron and steel industry varies significantly across countries. To produce 1 ton of pig iron in Canada, 130,000 liters of water are spent, to smelt 1 ton of pig iron in a blast furnace in the USA - 103,000 liters, steel in electric furnaces in France - 40,000 liters, and in Germany - 8000–12,000 liters.

Electric power industry.

To produce electricity, hydroelectric power plants use the energy of falling water to drive hydraulic turbines. In the USA, 10,600 billion liters of water are consumed daily at hydroelectric power plants.

Wastewater.

Water is necessary for the evacuation of domestic, industrial and agricultural wastewater. Although about half of the population, such as the United States, is served by sewer systems, wastewater from many homes is still simply dumped into septic tanks. But increasing awareness of the consequences of water pollution through such outdated sewer systems has stimulated the installation of new systems and the construction of water treatment plants to prevent pollutants from infiltrating into groundwater and untreated wastewater from flowing into rivers, lakes and seas.

WATER SHORTAGE

When water consumption exceeds water supply, the difference is usually compensated by its reserves in reservoirs, since usually both demand and water supply vary by season. A negative water balance occurs when evaporation exceeds precipitation, so a moderate decrease in water reserves is common. Acute shortage occurs when water flow is insufficient due to prolonged drought or when, due to poor planning, water consumption continually increases at a faster rate than expected. Throughout history, humanity has suffered from water shortages from time to time. In order not to experience a shortage of water even during droughts, many cities and regions try to store it in reservoirs and underground collectors, but at times additional water-saving measures are needed, as well as its normalized consumption.

OVERCOMING WATER SCARCITY

Flow redistribution is aimed at providing water to those areas where it is scarce, and water conservation is aimed at reducing irreplaceable water losses and reducing local demand for it.

Redistribution of runoff.

Although traditionally many large settlements arose near permanent water sources, nowadays some settlements are also created in areas that receive water from afar. Even when the source of the supplementary water supply is within the same state or country as the destination, technical, environmental or economic problems arise, but if the imported water crosses state borders, the potential complications increase. For example, spraying silver iodide into clouds causes an increase in precipitation in one area, but it may cause a decrease in precipitation in other areas.

One of the large-scale flow transfer projects proposed in North America involves diverting 20% of excess water from the northwestern regions to arid regions. At the same time, up to 310 million m 3 of water would be redistributed annually, a through system of reservoirs, canals and rivers would facilitate the development of navigation in the interior regions, the Great Lakes would receive an additional 50 million m 3 of water annually (which would compensate for the decrease in their level), and up to 150 million kW of electricity would be generated. Another grand plan for the transfer of flow is associated with the construction of the Grand Canadian Canal, through which water would be directed from the northeastern regions of Canada to the western ones, and from there to the United States and Mexico.

The project of towing icebergs from Antarctica to arid regions, for example, to the Arabian Peninsula, is attracting much attention, which will annually provide fresh water to 4 to 6 billion people or irrigate approx. 80 million hectares of land.

One of the alternative methods of water supply is the desalination of salt water, mainly ocean water, and its transportation to places of consumption, which is technically feasible through the use of electrodialysis, freezing and various distillation systems. The larger the desalination plant, the cheaper it is to obtain fresh water. But as the cost of electricity increases, desalination becomes economically unviable. It is used only in cases where energy is readily available and other methods of obtaining fresh water are impractical. Commercial desalination plants operate on the islands of Curacao and Aruba (in the Caribbean), Kuwait, Bahrain, Israel, Gibraltar, Guernsey and the USA. Numerous smaller demonstration plants have been built in other countries.

Protection of water resources.

There are two widespread ways to conserve water resources: preserving existing supplies of usable water and increasing its reserves by constructing more advanced collectors. The accumulation of water in reservoirs prevents its flow into the ocean, from where it can only be extracted again through the process of the water cycle in nature or through desalination. Reservoirs also make it easier to use water at the right time. Water can be stored in underground cavities. In this case, there is no loss of moisture due to evaporation, and valuable land is saved. The preservation of existing water reserves is facilitated by channels that prevent water from seeping into the ground and ensure its efficient transportation; using more efficient irrigation methods using wastewater; reducing the volume of water flowing from fields or filtering below the root zone of crops; careful use of water for domestic needs.

However, each of these methods of conserving water resources has one or another impact on the environment. For example, dams spoil the natural beauty of unregulated rivers and prevent the accumulation of fertile silt deposits on floodplains. Preventing water loss as a result of filtration in canals can disrupt the water supply of wetlands and thereby adversely affect the state of their ecosystems. It may also prevent groundwater recharge, thereby affecting water supplies to other consumers. And to reduce the volume of evaporation and transpiration by agricultural crops, it is necessary to reduce the area under cultivation. The latter measure is justified in areas suffering from water shortages, where savings are being made by reducing irrigation costs due to the high cost of energy required to supply water.

WATER SUPPLY

The sources of water supply and reservoirs themselves are important only when water is delivered in sufficient volume to consumers - to residential buildings and institutions, to fire hydrants (devices for collecting water for fire needs) and other public utilities, industrial and agricultural facilities.

Modern water filtration, purification and distribution systems are not only convenient, but also help prevent the spread of water-borne diseases such as typhoid and dysentery. A typical city water supply system involves drawing water from a river, passing it through a coarse filter to remove most of the pollutants, and then through a measuring station where its volume and flow rate are recorded. The water then enters the water tower, where it is passed through an aeration plant (where impurities are oxidized), a microfilter to remove silt and clay, and a sand filter to remove remaining impurities. Chlorine, which kills microorganisms, is added to the water in the main pipe before entering the mixer. Ultimately, purified water is pumped into a storage tank before being sent to the distribution network to consumers.

The pipes at the central waterworks are usually cast iron and have a large diameter, which gradually decreases as the distribution network expands. From street water mains with pipes with a diameter of 10–25 cm, water is supplied to individual houses through galvanized copper or plastic pipes.

Irrigation in agriculture.

Since irrigation requires huge amounts of water, water supply systems in agricultural areas must have a large capacity, especially in arid conditions. Water from the reservoir is directed into a lined, or more often unlined, main canal and then through branches into distribution irrigation canals of various orders to farms. Water is released onto the fields as a spill or through irrigation furrows. Because many reservoirs are located above irrigated land, water flows primarily by gravity. Farmers who store their own water pump it from wells directly into ditches or storage reservoirs.

For sprinkling or drip irrigation, which has been practiced recently, low-power pumps are used. In addition, there are giant center-pivot irrigation systems that pump water from wells in the middle of the field directly into a pipe equipped with sprinklers and rotating in a circle. The fields irrigated in this way appear from the air as giant green circles, some of them reaching a diameter of 1.5 km. Such installations are common in the US Midwest. They are also used in the Libyan part of the Sahara, where more than 3,785 liters of water per minute are pumped from the deep Nubian aquifer.