Water resources and water quality. Water management

The water resources considered are surface runoff (rivers, lakes and other bodies of water), underground runoff (groundwater and groundwater), glacier water, and precipitation, which are sources of water to meet economic and domestic needs. Water is a unique type of resource. It combines the nature of both exhaustible (groundwater) and inexhaustible (surface runoff) reserves. Water in nature is in continuous movement, so its distribution across the territory, seasons and years is subject to significant fluctuations.

Russia has significant reserves of fresh water. River waters are most widely used in the national economy. The rivers of Russia belong to the basins of three oceans, as well as to the internal Caspian basin, which occupies most of the European part of Russia. Most of the rivers in Russia belong to the Arctic Ocean basin. Rivers flowing into northern seas, the longest and deepest. The longest river is the Lena (4400 km), the deepest river is the Yenisei. In the southern parts of Siberia the rivers are swift and rapid. The largest hydroelectric power stations in the country were built on these sections - Krasnoyarsk and Sayano-Shushenskaya on the Yenisei, Novosibirsk on the Ob, Irkutsk, Bratsk, Ust-Ilimsk on the Angara, etc. The rivers of the European part of the Arctic Ocean basin - Pechora, Mezen, Northern Dvina, Onega - are much shorter Siberian rivers. To the pool Pacific Ocean include many rivers. The main rivers of this basin are the Amur and its tributaries the Zeya, Bureya, and Ussuri.

Pool Atlantic Ocean takes smallest area from the entire country. Rivers flow west to the Baltic Sea (Neva) and south to the Azov and Black Sea (Don, Kuban, etc.). The Neva occupies a special place. This short river (74 km) carries a huge amount of water - four times more than the Dnieper, which is over 2000 km long.

Most of European Russia is occupied by the internal basin of the Caspian Sea. The rivers Volga, Ural, Terek and others flow into the Caspian Sea. In European Russia, the longest river is the Volga (3530 km). There are many hydroelectric power stations on the Volga: Volzhskaya named after. Lenin, Saratov, Volzhskaya named after. XXI Congress of the CPSU, etc.

The main consumers of water resources in our country are water supply, hydropower, and artificial irrigation.

Water supply is a set of different ways of using water resources by industry, utilities and the population with a large share of irreversible losses and varying degrees of pollution. It is this aspect of water use that creates the problem of qualitative deterioration and reduction of water reserves, which becomes increasingly aggravated as production grows. Solving it requires the redistribution of water resources between regions, careful use of reserves, construction treatment facilities, wide application closed cycles of water use, etc.

Hydropower uses the energy of flowing water, the reserves of which are then completely returned to the watercourse. Russia has the world's largest hydropower reserves, which account for about 1/10 of the world's reserves. Russia's hydropower resources are distributed unevenly. Most of them are in Siberia and Far East, with the main hydropower reserves concentrated in the basins of the Yenisei, Lena, Ob, Angara, Irtysh and Amur rivers. The Lena ranks first among Russian rivers in terms of hydropower reserves. The rivers of the North Caucasus are rich in hydropower resources. A significant part of the country's technically possible hydropower resources is located in the Volga and Central regions of Russia, where the hydropower reserves of the Volga basin are especially large.

River flow and glacier resources are used for artificial irrigation. The main irrigation areas are arid territories: the North Caucasus, Trans-Volga region.

If you look at our planet from space, the Earth appears as a blue ball completely covered with water. And the continents are like small islands in this endless ocean. This is understandable. Water occupies 70.8% of the planet's surface, leaving only 29.2% of land. The watery shell of our planet is called the hydrosphere. Its volume is 1.4 billion cubic meters.

Water appeared on our planet about 3.5 billion years ago in the form of vapor that was formed as a result of degassing of the mantle. Currently, water is the most important element in the Earth's biosphere, since it cannot be replaced by anything. Fortunately, water resources are considered inexhaustible because scientists have come up with a way to desalinate salt water.

The main purpose of water is natural resource- maintaining the vital activity of all living things - plants, animals and humans. It is the basis of all life on our planet, the main supplier of oxygen in the most important process on Earth - photosynthesis.

Water is the most important factor in climate formation. By absorbing heat from the atmosphere and releasing it back, water regulates climate processes.

It is impossible not to note the role of water sources in the modification of our planet. From time immemorial, people have settled near reservoirs and water sources. Water serves as one of the main means of communication. There is an opinion among scientists that if our planet were entirely dry land, then, for example, the discovery of America would be delayed for several centuries. And we would hardly have learned about Australia for another 300 years.

Types of Earth's water resources

Water resources our planet is the reserves of all the water. But water is one of the most common and most unique compounds on Earth, since it is present in three states at once: liquid, solid and gaseous. Therefore, the Earth's water resources are:

. Surface waters (oceans, lakes, rivers, seas, swamps)

. The groundwater.

. Artificial reservoirs.

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

. Water contained in plants and animals.

. Atmospheric vapors.

The last 3 points relate to potential resources, because humanity has not yet learned to use them.

Fresh water is the most valuable; it is used much more widely than sea, salt water. Of the total water reserves in the world, 97% of water comes from seas and oceans. 2% of fresh water is contained in glaciers, and only 1% is fresh water reserves in lakes and rivers.

Use of water resources

Water resources are the most important component of human life. People use water in industry and at home.

According to statistics, water resources are most used in agriculture(about 66% of all fresh water reserves). About 25% is used by industry and only 9% goes to meet the needs of utilities and households.

For example, to grow 1 ton of cotton, about 10 thousand tons of water are needed, for 1 ton of wheat - 1,500 tons of water. To produce 1 ton of steel, 250 tons of water are required, and to produce 1 ton of paper, at least 236 thousand tons of water are needed.

A person needs to drink at least 2.5 liters of water per day. However, on average per 1 person per major cities spend at least 360 liters per day. This includes the use of water in sewers, water supply, for watering streets and extinguishing fires, for washing vehicles, etc., etc.

Another option for using water resources is water transport. Every year, over 50 million tons of cargo are transported across Russian waters alone.

Don't forget about fisheries. Breeding marine and freshwater fish plays an important role in the economies of countries. Moreover, fish farming requires pure water saturated with oxygen and free of harmful impurities.

An example of the use of water resources is also recreation. Who among us doesn’t like to relax by the sea, barbecue on the river bank or swim in the lake? In the world, 90% of recreational facilities are located near water bodies.

Water conservation

Today there are only two ways to conserve water resources:

1. Preservation of existing fresh water reserves.

2. Creation of more advanced collectors.

The accumulation of water in reservoirs prevents its flow into the world's oceans. And storing water, for example, in underground cavities, allows you to protect water from evaporation. The construction of canals allows us to solve the issue of delivering water without it seeping into the ground. New methods of irrigating agricultural land are also being developed that make it possible to use wastewater.

But each of these methods has an impact on the biosphere. Thus, the reservoir system prevents the formation of fertile silt deposits. Channels preventing replenishment groundwater. And water filtration in canals and dams is the main risk factor for swamps, which leads to disturbances in the planet’s ecosystem.

Today is the most effective measure for the protection of water resources is considered a method of purification Wastewater. Various ways allow you to remove up to 96% of harmful substances from water. But this is often not enough, and the construction of more advanced treatment facilities often turns out to be economically unprofitable.

Water pollution problems

Population growth, development of production and agriculture - these factors have led to a shortage of fresh water for humanity. The share of polluted water resources is growing every year.

Main sources of pollution:

. Industrial wastewater;

. Wastewater from municipal routes;

. Drains from fields (when the water is oversaturated with chemicals and fertilizers);

. Burial in reservoirs radioactive substances;

. Drains from livestock complexes (such water contains a lot of biogenic organic matter);

. Shipping.

Nature provides for the self-purification of reservoirs, which occurs due to the water cycle in nature, due to the life activity of plankton, irradiation ultraviolet rays, sedimentation of insoluble particles. But all these processes can no longer cope with the mass of pollution that human activity brings to the planet’s water resources.

WATER RESOURCES

WATER RESOURCES

water suitable for domestic use. Fresh water resources are especially important, accounting for less than 3% of the total volume of the hydrosphere. The supply of available fresh water is distributed extremely unevenly: in Africa, only 10% of the population is provided with regular water supply, and in Europe this figure exceeds 95%. The water situation in big cities around the world (Paris, Tokyo, Mexico City, New York) is becoming increasingly tense. The shortage is associated with increased consumption of reserves and pollution of the hydrosphere.

Concise geographical dictionary.

EdwART.

2008. Water resources usable fresh water contained in rivers, lakes, reservoirs, glaciers, groundwater, as well as soil moisture. Atmospheric vapors, salty waters of oceans and seas that are not used in agriculture constitute potential water resources. The total volume of water resources is estimated at 1.4 billion km³, of which only 2% is fresh water, and only 0.3% is technically available for use. Water intake from all sources is approx. 4000 km³ per year. Water resources are used in the energy sector, for land irrigation, industrial, agricultural, municipal water supply, and also as transport routes. When using water resources, their quantity either does not change at all (for example, in hydropower, water transport 1 /3 of the world's population lives in countries experiencing fresh water shortages. 50% of ter is in the deficit zone. Asia, 20% Europe, approx. 30% Northern America, almost all of Australia. Regions with excess water resources are located in equatorial and subpolar latitudes, as well as in many areas of the temperate zone. Russia's surface runoff accounts for 10% of the world's. However, 90% comes from the bass. North Arctic and Pacific Oceans at the same time on bass. The Azov and Caspian Seas, where more than 80% of the population lives, account for less than 8% of the annual river flow.

Geography. Modern illustrated encyclopedia. - M.: Rosman. Edited by prof. A. P. Gorkina. 2006 .

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.).
Water is the only substance that exists in nature in liquid, solid and gaseous states. The meaning of liquid water varies significantly depending on location and application. Fresh water is more widely used than salt water. Over 97% of all water is concentrated in the oceans and inland seas. Still ok. 2% comes from fresh water contained in cover and mountain glaciers, and only less than 1% comes from fresh water in lakes and rivers, underground and groundwater.
Water, the most abundant compound on Earth, has unique chemical and physical properties. Since it easily dissolves mineral salts, living organisms absorb it along with it. nutrients without any significant changes to its own chemical composition. Thus, water is necessary for the normal functioning of all living organisms. A water molecule consists of two hydrogen atoms and one oxygen atom. Its molecular weight is only 18, and its boiling point reaches 100°C at atmospheric pressure 760 mmHg Art. At higher altitudes, where the pressure is lower than at sea level, water boils at lower temperatures. When water freezes, its volume increases by more than 11%, and the expanding ice can break water pipes and pavements and destroy rocks, turning them into loose soil. Ice is less dense than liquid water, which explains its buoyancy.
Water also has unique thermal properties. When its temperature drops to 0°C and it freezes, 79 calories are released from each gram of water. During night frosts, farmers sometimes spray their gardens with water to protect the buds from frost damage. When water vapor condenses, each gram of it releases 540 calories. This heat can be used in heating systems. Due to its high heat capacity, water absorbs a large number of heat without changing temperature.
Water molecules are held together by “hydrogen (or intermolecular) bonds” when the oxygen of one water molecule combines with the hydrogen of another molecule. Water is also attracted to other hydrogen and oxygen containing compounds (called molecular attraction). The unique properties of water are determined by the strength of hydrogen bonds. The forces of adhesion and molecular attraction allow it to overcome gravity and, due to capillarity, to rise up through small pores (for example, in dry soil).
DISTRIBUTION OF WATER IN NATURE
When the temperature of water changes, the hydrogen bonds between its molecules also change, which in turn leads to a change in its state - from liquid to solid and gaseous.
Since liquid water is an excellent solvent, it is rarely absolutely pure and contains minerals in a dissolved or suspended state. Only 2.8% of the 1.36 billion km 3 of all water available on Earth is fresh water, and most of it (about 2.2%) is in a solid state in mountain and cover glaciers (mainly in Antarctica) and only 0.6% - in liquid. Approximately 98% of liquid fresh water is concentrated underground. The salty waters of the oceans and inland seas, which occupy more than 70% of the earth's surface, make up 97.2% of all the earth's waters. see also OCEAN.
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 ( see also RAIN). 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. see also HYDROLOGY.
Gravity promotes the redistribution of liquid moisture from higher to lower areas, both on the earth's surface and under it. Water originally set in motion solar energy, in the seas and oceans it moves 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 geographical location and the sizes 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). Part 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 to the north Central America 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, while in central Canada and in the western USA - 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.
For the most part former USSR it also receives less than 500 mm of precipitation per year.
Time cycles of water availability. At any point 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 . IN modern conditions they are not replenished by surface fresh waters, but are depleted when pumped. 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, over-abstraction of groundwater leads to the replacement of fresh water in the aquifer with seawater and saline water, thereby degrading local freshwater sources.
Gradual deterioration of groundwater quality as a result of salt accumulation may 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.
As a result of indiscriminate discharge or burial of toxic chemical substances they seep into aquifers, which are sources of 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. see also river
Natural freshwater lakes holding approx. 125 thousand km 3 of water, along with rivers and artificial reservoirs, are an important source 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. see also lake .
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 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 end life cycle in inland fresh waters, but spend most of their lives in the ocean. Some fish (for example, trout) need vital cold water, while others (like perch) prefer warm.
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 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 water, filtered and treated special treatment 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 calcium and magnesium carbonates) soap foams well, it 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 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 estimated amount of water used just to grow (not process or prepare) the food crops consumed daily by one person in Western countries, – for breakfast 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 the water is flowing not only for watering crops, but also for replenishing groundwater reserves (to prevent the groundwater level from falling 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 liters of water for every ton of production, but up to 4,000 liters of this is deadweight loss (mainly evaporation), and therefore approximately 82,000 liters 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 ( see also HYDROPOWER).
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 wastewater treatment plants to prevent the infiltration of pollutants into groundwater and the flow of untreated wastewater into rivers, lakes and seas ( see also WATER POLLUTION).
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 supply 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 They 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 alternative methods 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 systems distillation. 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; application more effective methods irrigation 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 - in residential buildings and institutions, to fire hydrants (devices for drawing water for fire needs) and other objects utilities, to 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, 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 enormous 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 different order to the 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 sprinkler or drip irrigation practiced in Lately, use low power pumps. 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.

Encyclopedia Around the World. 2008 .

Detailed solution Paragraph § 16 on geography for 8th grade students, authors I.I. Barinova 2015

Questions at the beginning of a paragraph

1) Remember from natural history, botany, history, and previous geography courses what role water plays in human life.

Water – drinking, meeting household needs, necessary raw material for industry, universal solvent, component all living organisms.

2) In what state is water found in nature?

Water occurs in nature in liquid, solid and gaseous states.

3) What is the global water cycle? What role does it play in human life and activity?

The water cycle in nature (hydrological cycle) is the process of cyclic movement of water in the earth's biosphere. The importance of the water cycle is great, since it not only unites parts of the hydrosphere, but also connects all the shells of the Earth with each other: the atmosphere, hydrosphere, lithosphere and biosphere. During the cycle, water can be in three states: liquid, solid, gaseous. It carries a huge amount of substances necessary for life on Earth.

Questions in a paragraph

*Which rivers of our country do you think are the richest in energy resources? Why did you decide so?

The rivers of Siberia have enormous hydroelectric potential. It is here, on the Yenisei and Angara rivers, that the largest hydroelectric power stations were built. This is due to their high water content, significant drop and slope.

*Use the map to determine which areas of our country are rich in water resources and which are poor. Remember where the large rivers of Russia get their food from.

In general, the country is well provided with water resources, but they are distributed extremely unevenly across its territory, both in space and time. The northern regions and Siberia are well supplied with these resources; the rivers of this region have enormous hydropower potential. And the most developed regions of the country experience a lack of water, especially in the southern part of European Russia. The use of water resources is also complicated by the fact that the rivers carry the most water during the spring flood, and the greatest need for water is felt in the summer. The rivers of the Arctic Ocean basin are the longest and deepest. These are the Lena, Yenisei, and Ob rivers. The feeding of these rivers is mixed, mainly snow. Rivers of the Pacific Ocean basin The main one is the Amur with tributaries - Zeya, Bureya, Ussuri. The food is predominantly rain-fed. Rivers of the Atlantic Ocean basin. These are rivers flowing into the Black, Azov and Baltic seas. Such as the Neva, Western Dvina, Dnieper, Don, Kuban. The food is predominantly snowy.

*Why there are floods on rivers. What measures are being taken to combat them?

Long rains, melting snow, bursting of dams and reservoirs. Most effective method river flood control - regulation of river flow by creating reservoirs. They even out the river flow, making it greater in summer and less in spring than in its absence. To combat floods on the seashore, protective dams are used. Another way to combat floods is to deepen riffles and other shallows. To protect against floods when ice melts on rivers, dynamite (or another explosive) is most often used, exploded in certain places of the river, which, by destroying hummocks, allows water to flow freely and direct it in the desired direction.

Questions at the end of the paragraph

1. What are water resources? What do you need to know to assess a country's water resources?

Water resources – surface and groundwater that are used or can be used for water supply to the population, in agriculture and industry. To assess, it is necessary to know the distribution of water resources across the territory and their distribution by season.

2. Indicate the main features of Russia’s water resources.

They are extremely unevenly distributed over the territory, the distribution of runoff across seasons is uneven, areas of consumption and areas of resource concentration are separated.

3. How do human activities affect water resources? Give positive and negative examples?

Negative impact - pollution during the construction of hydroelectric power stations, shipping, discharge of industrial waters, deforestation increases the unevenness of the flow.

Positive impact – flow regulation.

4. What measures are being taken in our country to protect and protect water resources?

Installation of treatment facilities at enterprises, afforestation of slopes and planting of forest belts, construction of reservoirs in mountainous areas.

FINAL ASSIGNMENTS ON THE TOPIC

1. Name all the types inland waters. Describe the role of each of them in nature and economic activity.

Rivers, lakes, swamps, groundwater, glaciers, permafrost or permafrost, artificial reservoirs and ponds, canals. Rivers drain water from land. Large rivers serve as transport routes. Some rivers have hydroelectric potential. Rivers, lakes, reservoirs, groundwater - these are all sources for domestic water supply, water supply for agriculture, and industry.

Significant reserves of fresh water are concentrated in glaciers. grains regulate river flow. Shipping routes pass through them. There are numerous recreational areas on their banks. Lakes actively influence other components of nature. They change the topography, forming the bottom and shores. By filling their basins with peat, silt and salts, lakes create mineral deposits.

Lakes influence the climate. In summer they moderate the heat, in winter they soften the cold, and moisten the banks with moisture evaporating from their surface. Swamps are an important source of nutrition for rivers and lakes.

A lot grows in the swamps healthy berries: cranberry, cloudberry. They are the natural habitat of many animals. Therefore, the conservation of wetlands is important for the protection and rational use riches of nature. The practical uses of swamps are also varied. About 80% of the country's peat reserves are concentrated in swamps, which is used as raw material for chemical industry and fertilizer in agriculture. Permafrost has a significant impact on both nature and human life and activity. Permafrost affects vegetation, as it constantly cools the soil and ground layer of air. It limits the depth of penetration of plant roots into the soil and their water supply. Therefore, in permafrost areas, plants grow that have a shallow root system.

Permafrost is waterproof and therefore contributes to swamping of areas. During the construction of roads, pipelines, and buildings, permafrost may thaw. This threatens subsidence and failure of the soil and the destruction of constructed structures. Therefore, permafrost must be preserved during construction. For this purpose, houses and pipelines are raised above the ground on special piles, and roads are created on high protective cushions of soil.

3. What is the river regime? What does it depend on? What does it affect?

River regime is regular (daily, annual) changes in the state of the river, determined by the physical and geographical properties of its drainage basin, primarily by climate. The river regime is manifested in fluctuations in water levels and flows, the time of establishment and disappearance of ice cover, water temperature, the amount of sediment carried by the river, etc. Water mode affects water consumption and runoff.

4. What characteristics of a river do you need to know to use its resources in the economy?

Slope, mode, amount of runoff.

5. Explain the reasons for the formation of permafrost. How does permafrost affect other components of nature, human life and activity?

The reason for the formation of permafrost is strong soil freezing, which does not thaw for a long time. Permafrost limits the depth of root penetration, preventing agriculture. Water accumulating in the permafrost makes the area swampy. Sagging and swelling are formed. Permafrost complicates the construction of roads, buildings, and mining.

7. Prove the truth of the saying “Water is life.”

The role of water in human life is undeniably high. It serves as the basis for the good functioning of the entire body. There are in the water various substances, the origin of which is varied, both organic and inorganic. It makes up almost three-quarters of an adult's weight. After all, it was water that created the Earth, made it what it is now, and gave birth to life. Moreover, water is the most amazing substance on Earth, and the more we learn about it, the more we are amazed.

Probably few of you have thought about amazing properties water, and this is perhaps understandable: after all, water surrounds us everywhere, it is very common on our planet. Water occupies 3/4 of the Earth's surface. About 1/5 of the land is covered with solid water (ice and snow), a good half of it is always covered with clouds, which consist of water vapor and tiny droplets of water, and where there are no clouds, there is always water vapor in the air. It is very common on our planet; even the human body is 71 percent water. With a loss of 6-8% of moisture from body weight, a person falls into a semi-fainting state; with a loss of 12% or more percent of moisture, death occurs.

The Earth's water resources consist of underground and surface waters planets. They are used not only by humans and animals, but are also needed for various natural processes. Water (H2O) comes in liquid, solid or gaseous form. The totality of all water sources makes up the hydrosphere, that is, the water shell, making up 79.8% of the Earth's surface. It consists of:

• oceans;
• seas;
• lakes;
• swamps;
• artificial reservoirs;
• groundwater;
• atmospheric vapors;
• moisture in the soil;
• snow covers;
• glaciers.

To maintain life, people must drink water every day. Only fresh water is suitable for this, but on our planet there is less than 3% of it, but only 0.3% is currently available. Russia, Brazil and Canada have the largest reserves of drinking water.

Use of water resources

Water appeared on Earth approximately 3.5 billion years ago and cannot be seen as any other resource. The hydrosphere is considered one of the inexhaustible riches of the world; in addition, scientists have invented a way to make salt water fresh so that it can be used for drinking.

Water resources are necessary not only to support the life of people, flora and fauna, but also supply oxygen through the process of photosynthesis. Water also plays a key role in climate formation. People use this most valuable resource in everyday life, in agriculture and industry. Experts have calculated that in large cities a person spends about 360 liters of water per day, and this includes the use of water supply, sewerage, preparing food and drinks, cleaning the house, washing, watering plants, washing Vehicle, fire fighting, etc.

The problem of hydrosphere pollution

One of the global problems is water pollution. Sources of water pollution:

• domestic and industrial wastewater;
• petroleum products;
• burial of chemical and radioactive substances in water bodies;
• shipping;
• municipal solid waste.

In nature, there is such a phenomenon as the self-purification of water bodies, but the anthropogenic factor influences the biosphere so much that over time, rivers, lakes, and seas become increasingly difficult to restore. Water becomes polluted and becomes unsuitable not only for drinking and household use, but also for the life of marine, river, ocean species of flora and fauna. To improve the condition environment, and in particular the hydrosphere, it is necessary to rationally use water resources, save them and carry out protective measures of water bodies.