Problems of rational use of water resources. Environmental problems of water resources

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Modern problems of water resources

Problems of clean water and protection aquatic ecosystems become more acute as the historical development of society, the impact on nature caused by scientific and technological progress is rapidly increasing. Already in many areas the globe there are great difficulties in providing water supply and water use due to the qualitative and quantitative depletion of water resources, which is associated with pollution and irrational use of water.

Water pollution mainly occurs due to the discharge of industrial, domestic and agricultural waste into it. In some reservoirs, pollution is so great that they have completely degraded as sources of water supply. A small amount of pollution cannot cause a significant deterioration in the condition of a reservoir, since it has the ability of biological purification, but the problem is that, as a rule, the amount of pollutants discharged into the water is very large and the reservoir cannot cope with their neutralization.

Water supply and use is often complicated by biological interference: the overgrowth of canals reduces them throughput, algal blooms worsen the quality of water, its sanitary condition, fouling interferes with navigation and the functioning of hydraulic structures. Therefore, the development of measures with biological interference acquires great practical importance and becomes one of the most important problems in hydrobiology. Due to the violation of the ecological balance in water bodies, there is a serious threat of a significant deterioration of the ecological situation as a whole. Therefore, mankind faces a huge task of protecting the hydrosphere and maintaining biological balance in the biosphere.

The problem of pollution of the oceans.

Oil and oil products are the most common pollutants in the oceans. By the beginning of the 1980s, about 6 million tons of oil were annually entering the ocean, which accounted for 0.23% of world production. The greatest losses of oil are associated with its transportation from production areas. Emergencies, discharge of washing and ballast water overboard by tankers - all this leads to the presence of permanent pollution fields along sea routes. In the period 1962-79, about 2 million tons of oil entered the marine environment as a result of accidents. Over the past 30 years, since 1964, about 2,000 wells have been drilled in the World Ocean, of which 1,000 and 350 industrial wells have been equipped in the North Sea alone. Due to minor leaks, 0.1 million tons of oil are lost annually. Large masses of oil enter the seas along rivers, with domestic and storm drains. The volume of pollution from this source is 2.0 million tons/year. Every year, 0.5 million tons of oil enters with industrial effluents. Getting into the marine environment, oil first spreads in the form of a film, forming layers of various thicknesses.

The oil film changes the composition of the spectrum and the intensity of light penetration into the water. Light transmission thin films crude oil is 1-10% (280nm), 60-70% (400nm). A film with a thickness of 30-40 microns completely absorbs infrared radiation. When mixed with water, oil forms an emulsion of two types: direct - "oil in water" - and reverse - "water in oil". When volatile fractions are removed, oil forms viscous inverse emulsions, which can remain on the surface, be carried by the current, wash ashore and settle to the bottom.

Pesticides. Pesticides are a group of man-made substances used to control pests and plant diseases. It has been established that pesticides, destroying pests, harm many beneficial organisms and undermine the health of biocenoses. In agriculture, the problem of the transition from chemical (polluting the environment) to biological (environmentally friendly) methods of pest control has long been faced. The industrial production of pesticides is accompanied by the appearance of a large number of by-products that pollute wastewater.

About half of the annual industrial production of this metal (910 thousand tons/year) ends up in the ocean in various ways. In areas polluted by industrial waters, the concentration of mercury in solution and suspension is greatly increased. Contamination of seafood has repeatedly led to mercury poisoning of the coastal population. Lead is a typical trace element found in all components of the environment: in rocks, soils, natural waters, the atmosphere, and living organisms. Finally, lead is actively dispersed into environment in the process of human economic activity. These are emissions from industrial and domestic effluents, with smoke and dust industrial enterprises, with exhaust gases from internal combustion engines.

Thermal pollution. Thermal pollution of the surface of reservoirs and coastal marine areas occurs as a result of the discharge of heated wastewater from power plants and some industrial production. The discharge of heated water in many cases causes an increase in water temperature in reservoirs by 6-8 degrees Celsius. The area of heated water spots in coastal areas can reach 30 square meters. km. A more stable temperature stratification prevents water exchange between the surface and bottom layers. The solubility of oxygen decreases, and its consumption increases, since with increasing temperature, the activity of aerobic bacteria that decompose organic matter increases. intensifies species diversity phytoplankton and the entire algae flora.

Pollution of freshwater reservoirs.

The water cycle, this long way of its movement, consists of several stages: evaporation, cloud formation, rainfall, runoff into streams and rivers, and evaporation again. Throughout its path, water itself is able to be cleaned of contaminants that enter it - decay products organic matter, dissolved gases and minerals, suspended solids. In places with a large concentration of people and animals, natural clean water is usually not enough, especially if it is used to collect sewage and transfer it away from settlements. If not much sewage enters the soil, soil organisms process them, reusing nutrients, and clean water seeps into neighboring streams. But if the sewage immediately enters the water, they rot, and oxygen is consumed for their oxidation. The so-called biochemical oxygen demand is created. The higher this requirement, the less oxygen remains in the water for living microorganisms, especially for fish and algae. Sometimes, due to lack of oxygen, all living things die.

Water becomes biologically dead; only anaerobic bacteria remain in it; they thrive without oxygen and in the course of their life they emit hydrogen sulfide - a poisonous gas with a specific smell of rotten eggs. The already lifeless water acquires a putrid smell and becomes completely unsuitable for humans and animals. This can also happen with an excess of substances such as nitrates and phosphates in the water; they enter the water from agricultural fertilizers in the fields or from sewage contaminated detergents. These nutrients stimulate the growth of algae, algae begin to consume a lot of oxygen, and when it becomes insufficient, they die. V natural conditions the lake, before silting up and disappearing, exists for about 20 thousand years. An excess of nutrients accelerates the aging process and reduces the life of the lake. V warm water oxygen is less soluble than in cold water. Some businesses, especially power plants, consume huge amounts of water for cooling purposes. The heated water is discharged back into the rivers and further disrupts the biological balance of the water system. Reduced oxygen content prevents the development of some living species and gives an advantage to others. But these new, heat-loving species also suffer greatly as soon as water heating stops.

Organic waste, nutrients and heat interfere with the normal development of freshwater ecosystems only when they overload those systems. But in recent years, ecological systems Huge quantities of absolutely alien substances have fallen, from which they do not know protection. Agricultural pesticides, metals and chemicals from industrial wastewater have made their way into the food chain aquatic environment which can have unpredictable consequences. Species at the beginning of the food chain can accumulate these substances in dangerous concentrations and become even more vulnerable to others. harmful effects.

Polluted water can be purified. Under favorable conditions, this occurs naturally in the process of the natural water cycle. But polluted basins - rivers, lakes, etc. - take much longer to recover. In order for natural systems to be able to recover, it is necessary, first of all, to stop the further flow of waste into rivers. Industrial emissions not only clog, but also poison wastewater. In spite of everything, some municipalities and industries still prefer to dump their waste into neighboring rivers and are very reluctant to do so only when the water becomes completely unusable or even dangerous.

In its endless cycle, water either captures and carries a lot of dissolved or suspended substances, or is cleared of them. Many of the impurities in the water are natural and get there with rain or groundwater. Some of the pollutants associated with human activities follow the same path. Smoke, ash and industrial gases, together with rain, fall to the ground; chemical compounds and sewage introduced into the soil with fertilizers enters the rivers with groundwater. Some waste follows man-made paths - drainage ditches and sewer pipes. These substances are usually more toxic but easier to control than those carried in the natural water cycle.

Global water consumption for economic and domestic needs is approximately 9% of the total river flow. Therefore, it is not the direct water consumption of hydro resources that causes a shortage of fresh water in certain regions of the globe, but their qualitative depletion. Over the past decades, industrial and municipal effluents have become an increasingly significant part of the fresh water cycle. About 600-700 cubic meters are consumed for industrial and domestic needs. km of water per year. Of this volume, 130-150 cubic meters are irretrievably consumed. km, and about 500 cubic meters. km of waste, the so-called waste water is discharged into rivers and seas.

Water purification methods.

An important place in the protection of water resources from qualitative depletion belongs to treatment facilities. Treatment facilities are different types depending on the main method of disposal of sewage. With the mechanical method, insoluble impurities are removed from wastewater through a system of settling tanks and various kinds of traps. In the past, this method has found the widest application for the treatment of industrial effluents. The essence of the chemical method lies in the fact that reagents are introduced into the wastewater treatment plants. They react with dissolved and undissolved contaminants and contribute to their precipitation in sumps, from where they are mechanically removed. But this method is unsuitable for treating wastewater containing a large number of heterogeneous pollutants. For industrial wastewater treatment complex composition electrolytic (physical) method is used. With this method electricity passed through industrial effluents, which leads to the precipitation of most pollutants. The electrolytic method is very efficient and requires relatively little investment in the construction of treatment plants. In our country in the city of Minsk, a whole group of factories using this method has achieved very high degree wastewater treatment.

When cleaning domestic wastewater, the biological method gives the best results. In this case, for the mineralization of organic contaminants, aerobic biological processes carried out with the help of microorganisms are used. biological method They are used both in conditions close to natural and in special biological treatment facilities. In the first case, domestic sewage is supplied to irrigation fields. Here, wastewater is filtered through the soil and at the same time undergoes bacterial treatment.

Irrigated fields accumulate a huge amount organic fertilizers which allows them to grow high yields. A complex system of biological treatment of polluted Rhine waters for the purposes of water supply for a number of cities in the country was developed and used by the Dutch. Pumping stations with partial filters have been built on the Rhine. From the river, water is pumped into shallow ditches onto the surface of the river terraces. Through the thickness of alluvial deposits, it is filtered, replenishing groundwater. Groundwater is supplied through wells for additional treatment and then enters the water supply system. Treatment facilities solve the problem of maintaining the quality of fresh water only up to a certain stage in the development of the economy of specific geographical regions. Then there comes a point when local water resources are no longer enough to dilute the increased amount of treated wastewater. Then the progressive pollution of water resources begins, and their qualitative depletion begins. In addition, at all treatment plants, as effluents increase, the problem arises of accommodating significant volumes of filtered pollutants.

Thus, the treatment of industrial and municipal wastewater provides only a temporary solution to local problems of protecting water from pollution. The cardinal ways of protection against pollution and destruction of natural aquatic and associated natural territorial complexes is to reduce or even completely stop the discharge of waste water, including treated wastewater, into water bodies. Perfection technological processes gradually solves these problems. For all more enterprises use a closed water supply cycle. In this case, the waste water undergoes only partial treatment, after which they can be used again in a number of industries.

Full implementation of all measures aimed at stopping sewage discharges into rivers, lakes and reservoirs is possible only under the conditions of the existing territorial production complexes. Within industrial complexes, complex technological links between various enterprises can be used to organize a closed water supply cycle. In the future, treatment facilities will not discharge waste water into water bodies, but will become one of the technological links in the closed water supply chain.

The progress of technology, careful consideration of local hydrological, physical and economic-geographical conditions in the planning and formation of territorial production complexes make it possible in the future to ensure the quantitative and qualitative preservation of all links in the fresh water cycle, to turn fresh water resources into inexhaustible ones. Increasingly, other parts of the hydrosphere are used to replenish freshwater resources. Yes, well developed efficient technology desalination of sea waters. Technically, the problem of seawater desalination has been solved. However, this requires a lot of energy, and therefore desalinated water is still very expensive. It is much cheaper to desalinate brackish groundwater. With the help of solar plants, these waters are desalinated in the south of the United States, on the territory of Kalmykia, Krasnodar Territory, Volgograd region. At international conferences on the problems of water resources, the possibilities of transferring fresh water preserved in the form of icebergs are being discussed.

For the first time, the American geographer and engineer John Isaacs suggested using icebergs to supply water to arid regions of the globe. According to his project, icebergs from the coast of Antarctica should be transported by ships to the cold Peruvian Current and further along the system of currents to the coast of California. Here they are attached to the shore, and the fresh water formed during the melting will be piped to the mainland. Moreover, due to condensation on the cold surface of icebergs, the amount of fresh water will be 25% greater than that contained in them themselves.

At present, the problem of pollution of water bodies (rivers, lakes, seas, ground water etc.) is the most relevant, because Everyone knows - the expression "water is life." A person cannot live without water for more than three days, but even understanding the importance of the role of water in his life, he still continues to exploit water bodies, irrevocably changing their natural regime with discharges and waste. The tissues of living organisms are 70% water, and therefore V.I. Vernadsky defined life as living water. There is a lot of water on Earth, but 97% is the salt water of the oceans and seas, and only 3% is fresh. Of these, three-quarters are almost inaccessible to living organisms, since this water is "conserved" in the glaciers of the mountains and polar caps (glaciers in the Arctic and Antarctic). This is a reserve of fresh water. Of the water available to living organisms, the bulk is contained in their tissues.

The need for water in organisms is very high. For example, for the formation of 1 kg of wood biomass, up to 500 kg of water is consumed. And so it must be spent and not polluted. The bulk of the water is concentrated in the oceans. Water evaporating from its surface gives life-giving moisture to natural and artificial land ecosystems. The closer an area is to the ocean, the more precipitation falls there. The land constantly returns water to the ocean, part of the water evaporates, especially forests, part is collected by rivers, which receive rain and snow water. The exchange of moisture between the ocean and land requires a very large amount of energy: it takes up to 1/3 of what the Earth receives from the Sun.

The water cycle in the biosphere before the development of civilization was balanced, the ocean received as much water from the rivers as it consumed during its evaporation. If the climate did not change, then the rivers did not become shallow and the water level in the lakes did not decrease. With the development of civilization, this cycle began to be violated, as a result of irrigation of agricultural crops, evaporation from land increased. The rivers of the southern regions became shallow, the pollution of the World Ocean, and the appearance of an oil film on its surface reduced the amount of water evaporated by the ocean. All this worsens the water supply of the biosphere. Droughts are becoming more frequent, and hotbeds of ecological disasters are emerging. In addition, the fresh water itself, which returns to the ocean and other bodies of water from land, is often polluted, and the water of many Russian rivers has become practically unfit for drinking.

A previously inexhaustible resource - fresh clean water - becomes exhaustible. Today, water suitable for drinking, industrial production and irrigation is in short supply in many parts of the world. Today, one cannot ignore this problem, because. if not us, then our children will be affected by all the consequences of anthropogenic water pollution. Even now, 20,000 people die every year due to dioxin pollution of water bodies in Russia. As a result of living in a dangerously poisoned habitat, cancer and other environmentally dependent diseases of various organs are spread. Therefore, this problem must be solved as soon as possible and the problem of cleaning industrial waste should be radically reconsidered.

pollution discharge freshwater body of water

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Leading Researcher, Department of Industrial and Regional Economics, RISS,

Candidate of Physical and Mathematical Sciences

Speech on situational analysis « Global problems water resources".

Approximately 54% of all available surface water runoff (usable, renewable fresh water) is currently used by the world's population. Taking into account the growth rate of the global economy, the growth rate of the world's population (an increase of 85 million people per year), and other factors, this figure is expected to increase to 70% by 2025.

According to the UN, in more than 18 countries there is a shortage of water (a level of 1000 or less cubic meters per 1 person/year), which makes it almost impossible to satisfy the needs of national economies and the communal needs of citizens. According to forecasts, the number of such states will grow to 33 by 2025.

At a critically low level of water availability are: the Middle East, North China, Mexico, the countries of North Africa, Southeast Asia and a number of post-Soviet states. According to the World Resource Institute, Kuwait is the hardest hit, with just 11 cubic meters per capita. meters of surface water, Egypt (43 cubic meters) and the United Arab Emirates (64 cubic meters). Moldova is in 8th place in the ranking (225 cubic meters), and Turkmenistan is in 9th place (232 cubic meters).

The Russian Federation has a unique water resource potential. The total fresh water resources of Russia are estimated at 10,803 cubic meters. km/year. Renewable water resources (the volume of annual river flow in Russia) is 4861 cubic meters. km, or 10% of the world's river flow (second place after Brazil). The main drawback of Russian water resources is their extremely uneven distribution across the country. In terms of local water resources, the Southern and Far Eastern federal districts In Russia, for example, they differ by almost 30 times, and by the water supply of the population by about 100 times.

Rivers are the basis of Russia's water resources. More than 120 thousand large rivers (more than 10 km long) flow through its territory with a total length of over 2.3 million km. The number of small rivers is much larger (over 2.5 million). They form about half of the total volume of river runoff; up to 44% of the urban and almost 90% of the rural population of the country live in their basins.

Groundwater, which is used mainly for drinking purposes, has a potential operational resource in excess of 300 cubic meters. km/year. More than a third of potential resources are concentrated in the European part of the country. Deposits explored to date groundwater have a total operating reserves of approximately 30 cubic meters. km / year.

In the country as a whole, the total water withdrawal for household needs is relatively small - 3% of the average long-term river flow. However, in the Volga basin, for example, it accounts for 33% of the country's total water withdrawal, and for a number of river basins, the figure exceeds the environmentally acceptable withdrawal volumes (Don - 64%, Terek - 68%, Kuban - 80% of the average annual flow). In the south of the European territory of Russia, almost all water resources are involved in economic activity. In the basins of the Ural, Tobol and Ishim rivers, water management tension has become a factor that, to a certain extent, hinders the development of the national economy.

Almost all rivers are subject to anthropogenic impact, the possibilities of extensive water intake for economic needs in many of them are generally exhausted. The water of many Russian rivers is polluted and unsuitable for drinking purposes. A serious problem is the deterioration of water quality in surface water bodies, which in most cases does not meet regulatory requirements and is assessed as unsatisfactory for almost all types of water use.

The degradation of small rivers is observed. There is their siltation, pollution, clogging, collapse of their banks. The uncontrolled withdrawal of water, the destruction and use of water protection belts and zones for economic purposes, the drainage of raised bogs led to the mass death of small rivers, thousands of which ceased to exist. Their total flow, especially in the European part of Russia, has decreased by more than 50%, resulting in the destruction of aquatic ecosystems, and makes these rivers unusable.

Today, according to experts, from 35% to 60% does not meet the standards drinking water in Russia and about 40% of surface and 17% of underground sources of drinking water supply. More than 6,000 sites of groundwater pollution have been identified on the territory of the country, the largest number of which is in the European part of Russia.

According to available estimates, every second resident Russian Federation forced to use for drinking purposes water that does not meet the established standards for a number of indicators. Almost a third of the country's population uses water sources without proper water treatment. At the same time, residents of a number of regions suffer from a lack of drinking water and the lack of proper sanitary and living conditions.

In particular, drinking water of poor quality in terms of sanitary-chemical and microbiological indicators is consumed by a part of the population in the Republics of Ingushetia, Kalmykia, Karelia, the Karachay-Cherkess Republic, in the Primorsky Territory, in the Arkhangelsk, Kurgan, Saratov, Tomsk and Yaroslavl regions, in the Khanty-Mansi Autonomous Okrug and Chukotka Autonomous Okrug.

The cause of the problem lies in the massive pollution of river and lake basins. At the same time, the main load on water bodies is created by industrial enterprises, objects of the fuel and energy complex, enterprises of the municipal economy and the agro-industrial sector. The annual volume of discharged effluents has practically not changed in recent years. In 2008, for example, it amounted to 17 cubic meters. km. However, it should be noted that against this background, there is a decrease in the volume of discharges of standard treated wastewater, which occurs due to overload treatment facilities, their poor-quality work, violations of technical regulations, shortages of reagents, breakthroughs and salvo discharges of pollution.

In Russia, especially in its European part, unacceptably large water losses are observed. On the way from the water source to the consumer, for example, in 2008, with a total volume of water intake from natural sources equal to 80.3 cubic meters. km, losses amounted to 7.76 km. In industry, water losses reach more than 25% (due to leaks and accidents in networks, infiltration, imperfection of technological processes). In housing and communal services, from 20 to 40% is lost (due to leaks in residential and public buildings, corrosion and deterioration of water supply networks); in agriculture - up to 30% (overwatering in crop production, overestimated water supply rates for animal husbandry).

The technological and technical backwardness of the water sector is growing, in particular, in the study and control of water quality, the preparation of drinking water, the treatment and disposal of sludge generated during the purification of natural and waste water. The development of promising schemes for the use and protection of waters necessary for sustainable water supply has been discontinued.

Global warming and climate change, as experts say, will lead to an improvement in the water supply of the Russian population as a whole. An increase in this indicator can be expected in the European territory of the country, in the Volga region, in the Non-Chernozem center, in the Urals, in most of Siberia and the Far East. At the same time, in a number of densely populated regions of the Black Earth Center of Russia (Belgorod, Voronezh, Kursk, Lipetsk, Oryol and Tambov regions), Southern (Kalmykia, Krasnodar and Stavropol Territory, Rostov region) and the southwestern part of the Siberian (Altai Territory, Kemerovo, Novosibirsk, Omsk and Tomsk regions) federal districts of the Russian Federation, which even in modern conditions have rather limited water resources, in the coming decades we should expect their further decrease by 10-20 %. In these regions, there may be a serious shortage of water, which can become a factor hindering economic growth and improving the welfare of the population, and there will be a need for strict regulation and limitation of water consumption, as well as attracting additional sources of water supply.

In the Altai Territory, in the Kemerovo, Novosibirsk, Omsk and Tomsk regions, the decrease in water resources, apparently, will not lead to critically low values of water supply and to a high load on water resources. However, given the fact that at present there are very serious problems, in the future they can become especially acute, especially in dry periods. This is primarily due to the great variability of water resources over time and territory, as well as the trend towards an increase in the intensity of use of transboundary river flows in China and Kazakhstan. To solve these problems, it is necessary to consider the possibilities of flow regulation and the conclusion of international agreements on the joint use of the water resources of the Irtysh.

Taking into account the growing influence of climate and its changes on the sustainability of the development of the economy and social sphere of the country, it seems necessary when developing the state water policy to provide for the inclusion of tasks related to climate change in it.

In general, experts consider natural disasters, population growth, resource-intensive industrial and agricultural production, waste pollution of natural reservoirs, coastal areas, groundwater and groundwater to be the main reasons for the negative trends in the field of water resources and possible restrictions on their use. In this regard, one of the most important tasks is to protect the country's aquatic ecosystems and promote the rational use of water in agriculture, industry and everyday life.

This is of particular relevance, since with the large natural resources of surface and groundwater in Russia, the predominant part of which is located in the eastern and northern regions, economically developed European regions with high level integrated use of water resources have practically exhausted the possibility of their development without rationalization of water use, saving water and restoring the quality of the aquatic environment.

- river runoff. Its defining value is in constant renewal. Of great importance are the water reserves in the lakes and, in addition,. Our country has significant reserves. At the same time, per unit area, the provision of the territory of Russia with a runoff layer turns out to be almost 2 times lower than the world average. However, the problem of water in our country is caused not so much by the general shortage of water resources, but by the natural features of objects, as well as the peculiarities of human activity.

Uneven distribution of water resources

Most of the water resources of Russia (9/10) are concentrated in the basins and, where less than 1/5 of the country's population lives. At the same time, most of the country's economic potential is concentrated in the Black basins, and, to a lesser extent,. These territories account for less than 10%, and here the shortage of water resources is most clearly manifested.

Seasonal fluctuations in river flow

In Russia, constant monitoring of the quality of surface and ground waters is carried out. There are about 4.5 thousand special tracking points at 1300 water bodies. Despite this, the quality of water in most rivers, lakes and reservoirs does not meet the relevant standards. A significant part of the pollutants enters rivers and lakes with atmospheric precipitation and snowmelt waters. They carry particles of dust, salt, oil products, mineral fertilizers, and pesticides from, from fields, city streets. In addition, about 60 cubic meters are dumped into water bodies every year. km of wastewater without the proper degree of treatment. They also contain a huge amount of harmful substances. Water in all the largest rivers in Russia - the Volga, Don, Ob, Yenisei - is assessed as "polluted", and in some of their tributaries as "very polluted". At the same time, the degree of river pollution increases from the upper reaches to the lower reaches. For some consumers of water resources (river transport, electric power industry), the quality of the water consumed is not of decisive importance. But in most cases, it is the quality of the water that limits its use. Of particular concern is the fact that more than half of the Russian population is forced to drink contaminated water.

Modern problems of water resources

The problems of clean water and the protection of aquatic ecosystems are becoming more acute as the historical development of society, the impact on nature caused by scientific and technological progress is rapidly increasing.

Already now, in many parts of the world, there are great difficulties in providing water supply and water use as a result of the qualitative and quantitative depletion of water resources, which is associated with pollution and irrational use of water.

A small amount of pollution cannot cause a significant deterioration in the condition of a reservoir, since it has the ability of biological purification, but the problem is that, as a rule, the amount of pollutants discharged into the water is very large and the reservoir cannot cope with their neutralization.

Water supply and water use is often complicated by biological interference: overgrowing of canals reduces their capacity, algae blooms worsen water quality, its sanitary condition, and fouling interferes with navigation and the functioning of hydraulic structures. Therefore, the development of measures with biological interference acquires great practical importance and becomes one of the most important problems in hydrobiology.

Due to the violation of the ecological balance in water bodies, there is a serious threat of a significant deterioration of the ecological situation as a whole. Therefore, mankind faces a huge task of protecting the hydrosphere and maintaining biological balance in the biosphere.

The problem of pollution of the oceans

The volume of pollution from this source is 2.0 million tons/year. Every year, 0.5 million tons of oil enters with industrial effluents. Getting into the marine environment, oil first spreads in the form of a film, forming layers of various thicknesses.

The oil film changes the composition of the spectrum and the intensity of light penetration into the water. Light transmission of thin films of crude oil is 1-10% (280nm), 60-70% (400nm).

A film with a thickness of 30-40 microns completely absorbs infrared radiation. When mixed with water, oil forms an emulsion of two types: direct - "oil in water" - and reverse - "water in oil". When volatile fractions are removed, oil forms viscous inverse emulsions, which can remain on the surface, be carried by the current, wash ashore and settle to the bottom.

Heavy metals. Heavy metals (mercury, lead, cadmium, zinc, copper, arsenic) are common and highly toxic pollutants. They are widely used in various industrial productions, therefore, despite the treatment measures, the content of heavy metal compounds in industrial wastewater is quite high. Large masses of these compounds enter the ocean through the atmosphere. Mercury, lead and cadmium are the most dangerous for marine biocenoses. Mercury is transported to the ocean with continental runoff and through the atmosphere. During the weathering of sedimentary and igneous rocks, 3.5 thousand tons of mercury are released annually. The composition of atmospheric dust contains about 12 thousand tons of mercury, and a significant part is of anthropogenic origin. About half of the annual industrial production of this metal (910 thousand tons/year) ends up in the ocean in various ways. In areas polluted by industrial waters, the concentration of mercury in solution and suspension is greatly increased. Contamination of seafood has repeatedly led to mercury poisoning of the coastal population. Lead is a typical trace element found in all components of the environment: in rocks, soils, natural waters, the atmosphere, and living organisms. Finally, lead is actively dispersed into the environment during human activities. These are emissions from industrial and domestic effluents, from smoke and dust from industrial enterprises, from exhaust gases from internal combustion engines.

Thermal pollution. Thermal pollution of the surface of reservoirs and coastal marine areas occurs as a result of the discharge of heated wastewater from power plants and some industrial production. The discharge of heated water in many cases causes an increase in water temperature in reservoirs by 6-8 degrees Celsius. The area of heated water spots in coastal areas can reach 30 square meters. km. A more stable temperature stratification prevents water exchange between the surface and bottom layers. The solubility of oxygen decreases, and its consumption increases, since with increasing temperature, the activity of aerobic bacteria that decompose organic matter increases. The species diversity of phytoplankton and the entire flora of algae is increasing.

Freshwater pollution

The water cycle, this long way of its movement, consists of several stages: evaporation, cloud formation, rainfall, runoff into streams and rivers, and again evaporation. Throughout its path, water itself is able to be cleaned of contaminants that enter it - decay products of organic substances, dissolved gases and minerals, suspended solids.

In places with a large concentration of people and animals, natural clean water is usually not enough, especially if it is used to collect sewage and transfer it away from settlements. If not much sewage enters the soil, soil organisms process them, reusing nutrients, and already clean water seeps into neighboring watercourses. But if the sewage immediately enters the water, they rot, and oxygen is consumed for their oxidation. The so-called biochemical oxygen demand is created. The higher this requirement, the less oxygen remains in the water for living microorganisms, especially for fish and algae. Sometimes, due to lack of oxygen, all living things die. Water becomes biologically dead; only anaerobic bacteria remain in it; they thrive without oxygen and in the course of their life they emit hydrogen sulfide - a poisonous gas with a specific smell of rotten eggs. The already lifeless water acquires a putrid smell and becomes completely unsuitable for humans and animals. This can also happen with an excess of substances such as nitrates and phosphates in the water; they enter the water from agricultural fertilizers in the fields or from sewage contaminated with detergents. These nutrients stimulate the growth of algae, algae begin to consume a lot of oxygen, and when it becomes insufficient, they die. Under natural conditions, the lake, before silting up and disappearing, exists for about 20 thousand years. An excess of nutrients accelerates the aging process and reduces the life of the lake. Oxygen is less soluble in warm water than in cold water. Some businesses, especially power plants, consume huge amounts of water for cooling purposes. The heated water is discharged back into the rivers and further disrupts the biological balance of the water system. Reduced oxygen content prevents the development of some living species and gives an advantage to others. But these new, heat-loving species also suffer greatly as soon as water heating stops. Organic waste, nutrients and heat interfere with the normal development of freshwater ecosystems only when they overload those systems. But in recent years, ecological systems have been bombarded with huge quantities of absolutely alien substances, from which they do not know protection. Agricultural pesticides, metals and chemicals from industrial wastewater have managed to enter the aquatic food chain with unpredictable consequences. Species at the beginning of the food chain can accumulate these substances at dangerous levels and become even more vulnerable to other harmful effects. Polluted water can be purified. Under favorable conditions, this occurs naturally in the process of the natural water cycle. But polluted basins - rivers, lakes, etc. - take much longer to recover. In order for natural systems to be able to recover, it is necessary, first of all, to stop the further flow of waste into rivers. Industrial emissions not only clog, but also poison wastewater. In spite of everything, some municipalities and industries still prefer to dump their waste into neighboring rivers and are very reluctant to do so only when the water becomes completely unusable or even dangerous.

Abstract on the World Economy on the topic: "Problems of the use of water resources"
Content

Introduction

Conclusion

Bibliography

Introduction

The organization of the rational use of water is one of the most important modern problems of the protection and transformation of nature. The intensification of industry and agriculture, the growth of cities, the development of the economy as a whole are possible only if fresh water reserves are preserved and increased. The cost of maintaining and reproducing water quality ranks first among all human costs for nature protection. The total cost of fresh water is much more expensive than any other type of raw material used.

Successful transformation of nature is possible only with sufficient quantity and quality of water. Usually any project of transformation of nature is connected to a large extent with one or another impact on water resources.

In connection with the development of the world economy, water consumption is growing at a rapid pace. It doubles every 8-10 years. At the same time, the degree of water pollution increases, i.e., their qualitative depletion occurs. The volume of water in the hydrosphere is very large, but mankind directly uses only a small part of fresh water. All this, taken together, determines the acuteness of the tasks of water protection, their paramount importance in the whole complex of problems of the use, protection and transformation of nature.

Land water resources and their distribution on the planet. Water supply of the countries of the world

Water occupies a special position among the natural resources of the Earth. The famous Russian and Soviet geologist Academician A.P. Karpinsky said that there is no more precious fossil than water, without which life is impossible. Water is the main condition for the existence of wildlife on our planet. Man cannot live without water. Water is one of the most important factors determining the distribution of productive forces, and very often the means of production. Water resources are the main life-giving resource of the Earth; waters suitable for their use in the national world economy. Waters are divided into two large groups: land waters, waters of the oceans. Water resources are distributed unevenly across the territory of our planet, renewal occurs due to the global water cycle in nature, and water is also used in all sectors of the world economy. It should be noted main feature water is the use of it directly on the “site”, which leads to a shortage of water in other areas. Difficulties in transporting water to the arid regions of the planet are associated with the problem of financing projects. Overall volume water on Earth is approximately 13.5 million cubic meters, that is, one person has an average of 250-270 million cubic meters. However, 96.5% are the waters of the World Ocean and another 1% are salty underground and mountain lakes and waters. Fresh water reserves are only 2.5%. The main reserves of fresh water are contained in glaciers (Antarctic, Arctic, Greenland). These strategic objects are used insignificantly, tk. Ice transportation is expensive. About 1/3 of the land area is occupied by arid (dry) belts:

North (deserts of Asia, the Sahara Desert in Africa, the Arabian Peninsula);

Southern (deserts of Australia - Great Sandy Desert, Atacama, Kalahari).

The largest volume of river runoff occurs in Asia and South America, and the smallest in Australia.

When assessing water availability per capita, the situation is different:

the most endowed resources of river runoff are Australia and Oceania (about 80 thousand m 3 per year) and South America(34 thousand m 3);

· Asia is the least provided (4.5 thousand m 3 per year).

The world average is about 8 thousand m 3 . Countries of the world provided with river runoff resources (per capita):

surplus: 25 thousand m 3 per year - New Zealand, Congo, Canada, Norway, Brazil, Russia.

· medium: 5-25 thousand m 3 - USA, Mexico, Argentina, Mauritania, Tanzania, Finland, Sweden.

Little: less than 5 thousand m 3 - Egypt, Saudi Arabia, China, etc.

Ways to solve the problem of water supply:

Implementation of a water supply policy (reducing water losses, reducing the water intensity of production)

attracting additional fresh water resources (desalination of sea waters, construction of reservoirs, transportation of icebergs, etc.)

· construction of treatment facilities (mechanical, chemical, biological).

Three groups of countries most endowed with water resources:

· more than 25 thousand m 3 per year - New Zealand, Congo. Canada, Norway, Brazil, Russia.

· 5-25 thousand m 3 per year - USA, Mexico, Argentina, Mauritania, Tanzania, Finland, Sweden.

· less than 5 thousand m 3 per year - Egypt, Poland, Algeria, Saudi Arabia, China, India, Germany.

Water functions:

drinking (for humanity as a vital source of existence);

· technological (in the world economy);

transport (river and sea transportation);

Energy (HPP, PES)

Structure of water consumption:

Reservoirs - about 5%

municipal and household services - about 7%

industry - about 20%

· Agriculture – 68% (almost the entire water resource is irretrievably used).

Several countries have the greatest hydropower potential: China, Russia, USA, Canada, Zaire, Brazil. The degree of use in the countries of the world is different: for example, in the countries of Northern Europe (Sweden, Norway, Finland) - 80 -85%; in North America (USA, Canada) - 60%); in Foreign Asia (China) - about 8-9%.

Modern large thermal power plants consume huge amounts of water. Only one station with a capacity of 300 thousand kW consumes up to 120 m 3 /s, or more than 300 million m 3 per year. Gross water consumption for these stations in the future will increase by about 9-10 times.

Agriculture is one of the most significant water users. It is the largest water consumer in the water management system. For the cultivation of 1 ton of wheat, 1500 m 3 of water is required during the growing season, 1 ton of rice - more than 7000 m 3. The high productivity of irrigated land has stimulated a sharp increase in the area worldwide - it is now equal to 200 million hectares. Making up about 1/6 of the total area under crops, irrigated lands provide about half of agricultural production.

A special place in the use of water resources is occupied by water consumption for the needs of the population. Domestic and drinking purposes in our country account for about 10% of water consumption. At the same time, uninterrupted water supply, as well as strict adherence to scientifically based sanitary and hygienic standards, are mandatory.

The use of water for economic purposes is one of the links in the water cycle in nature. But the anthropogenic link of the cycle differs from the natural one in that in the process of evaporation, part of the water used by man returns to the desalinated atmosphere. The other part (component, for example, in the water supply of cities and most industrial enterprises 90%) is discharged into water bodies in the form of wastewater contaminated with industrial waste.

The World Ocean is a storehouse of mineral, biological and energy resources. The oceans are the richest part of the planet in terms of natural resources. Significant resources are:

mineral resources (iron-manganese nodules)

energy resources (oil and natural gas)

biological resources (fish)

sea water (table salt)

The mineral resources of the bottom of the World Ocean are divided into two groups: shelf resources (coastal part of the ocean) and bed resources (deep water areas of the ocean).

Oil and natural gas are the main types of resources (more than half of all world reserves). More than 300 deposits have been developed and their intensive use is underway. The main areas of oil production and natural gas on the shelf are 9 main marine areas:

Persian Gulf (Kuwait, Saudi Arabia)

South China Sea (China)

Gulf of Mexico (USA, Mexico)

Caribbean Sea

North Sea (Norway)

Caspian lake

Bering Sea (Russia)

Sea of Okhotsk (Russia)

The World Ocean is rich in reserves of such an amazing mineral as amber, which is mined on the coast of the Baltic Sea, there are deposits of precious and semi-precious stones: diamonds and zirconium (Africa - Namibia, South Africa; Australia). Known places for the extraction of chemical raw materials: sulfur (USA, Canada), phosphorites (USA, South Africa, North Korea, Morocco). In deep-sea areas (ocean bed), iron-manganese nodules are mined (Pacific Ocean, Indian Ocean).

The energy resources of the World Ocean are expressed in the use of sea tides. Tidal power plants are built on the coast of those countries, the “ebb and flow” mode is carried out daily. (France, Russia - White, Okhotsk, Barents Seas; USA, Great Britain).

The biological resources of the World Ocean are diverse in species composition. These are various animals (zooplankton, zoobenthos) and plants (phytoplankton and phytobenthos). The most common are: fish resources (more than 85% of the used biomass of the ocean), algae (brown, red). More than 90% of fish is caught in the shelf zone in high (Arctic) and temperate latitudes. The most productive seas are: the Norwegian Sea, the Bering Sea, the Sea of Okhotsk and Sea of Japan. The reserves of sea water are large. Their volume is 1338 million km3. Sea water is a unique resource of our planet. Sea water is rich in chemical elements. The main ones are: sodium, potassium, magnesium, sulfur, calcium, bromine, iodine, copper. There are more than 75 of them in total. The main resource is table salt. The leading countries are: Japan and China. Besides chemical elements and trace elements, in the depths of sea waters and on the shelf, silver and gold, and uranium are being mined. The main thing is the fact that sea water is successfully desalinated and consumed in those countries that lack fresh inland water. It should be noted that not all countries of the world can afford such a luxury. Desalinated sea water is intensively used by Saudi Arabia, Kuwait, Cyprus, and Japan.