Water resource potential and water availability

Of all types of resources, water is the most unique resource. Water is the basis of all living things; all plant and animal organisms contain water. Most chemical reactions on Earth take place in an aquatic environment. While most mineral resources are interchangeable (for example, oil can be replaced by coal, gas; copper by aluminum, etc.), water cannot be replaced by anything. Water is something that no modern production can do without in one form or another. Moreover, drinking water is irreplaceable - a resource without which neither man nor the animal world can exist.

Water is one of the most common substances in nature. The world's oceans occupy 71% of the Earth's surface area. However, the distribution of land and ocean is uneven: in the northern hemisphere, land occupies 39%, and in the southern hemisphere, 19% of the surface. The waters of the globe are concentrated not only in oceans and seas. They are also found in rivers, lakes, glaciers, underground horizons, the atmosphere, soils, swamps, etc. The total volume of all the Earth's waters is estimated at approximately 1.5 billion km 3, and is called water potential of the planet. However, fresh waters are of greatest interest to humans. They account for only 2% of the planet's total water potential (the remaining 98% is salt water). These 2% are called potential water resources. It should be borne in mind that potential water resources, in addition to rivers, lakes and groundwater also include water from glaciers, snow covers, the atmosphere, permafrost, etc., i.e. those waters that are currently practically not used, but make up about 80% of all fresh water on the planet. Only 20% of potential water resources(i.e. from all the fresh waters of the planet), which are suitable and can actually be used in human economic activity, and are called water resources.

Table 6.1.

The above definitions are generally accepted, but are not absolutely correct. Already, desalination plants provide water to consumers in a number of countries located in water-scarce areas of the world. Yes and simply sea ​​water is increasingly used in many sectors of the economy - for technological needs, in industry, in the agricultural sector. In addition to the salty waters of the World Ocean, which are not formally included in the “water resources”, there is increasing consumer interest in the waters contained in icebergs, which, according to the above definitions, do not yet fall into the category of “resources”. However, in recent years, projects have been developed for their transportation and use in water-scarce areas as a source of fresh and drinking water. Some countries already have experience in bottling iceberg and glacier waters for sale as high-quality drinking water.

The hydrosphere is one of the most mobile components of the geosphere after the atmosphere. All waters of the hydrosphere are in constant motion, constituting a single cycle (Table 6.2), which occurs due to gravity and solar energy (about 23% of all incoming solar energy is spent on the water cycle). The water cycle is ensured by such processes as precipitation, runoff, infiltration, evaporation, condensation, etc. All waters of the Earth are involved in it, without exception, wherever they are: waters of internal runoff areas, glacial waters, soil moisture, etc. However, due to the cycle, the constant process of water renewal in different environments occurs at different speeds. Thus, atmospheric waters are completely renewed in 8 days, river waters - in 16 days, water contained in swamps is renewed in 5 years, and in lakes - in 17 years. It will take much longer to renew the water mass in the World Ocean and groundwater - 2.5 and 5 thousand years, respectively. And for the complete renewal of waters contained in glaciers, it takes as many as 8 thousand years. Being, in addition, difficult to access for exploitation, these waters are actually in a “canned” form. Thus, on average, only 0.04% of all water on the planet participates in the global water cycle annually, which is about 577 thousand km 3 . It is this annually renewable part that is most important for economic development because it is more accessible and its use does not cause significant damage to the total global moisture reserves.

Table 6.2.

Global water balance characteristics (thousand km 3 /year)

Receipt part of the balance sheet - - expense part of the balance sheet

Of all water resources, rivers and lakes, as well as groundwater, are of greatest practical interest for meeting human needs. It is their volumes that mainly determine the water resource potential of the territory. .

However, the presence of a large number of water bodies in a region does not always guarantee the absence of problems with water supply, since for optimal water supply The following conditions must be met: water must be supplied in the required volume, appropriate quality and in optimal mode. The possibility of meeting these requirements largely depends on the type of water bodies used, their hydrological regime and ecological condition.

In most countries, the current leading source of water supply is river water resources, the main feature of which is the ability to be renewed on average 23 times during the year during the cycle. Therefore, when assessing actual river water resources In any region, the simultaneous volume of water in rivers increases by 23 times. In general, for the world, the actual resources of river waters are 47 thousand cubic km/year. Indicators of resource availability of river flow are the basis for identifying water-scarce and water-abundant territories. And although the distribution of river runoff resources between parts of the world is not sharply uneven (Table 6.3), however, very strong regional differences are possible within each of them. Thus, the main water-scarce areas globe are the Persian Gulf, Central Asia, southern Africa, the western coasts of the USA and Mexico, etc., and the over-provided ones are the Amazon, Alaska, Canada, the equatorial regions of Africa, western and northeastern Oceania, etc.

Table 6.3.

Distribution of river flow resources

It is quite obvious that the resource provision of river flow cannot be analyzed without taking into account the peculiarities of its territorial distribution within the region, as well as population density and the location of main economic facilities. For example, specific indicators of river flow resource availability Australia is almost 20 times higher than Asia. And Ukraine, which ranks first in terms of total water resources among the CIS countries (not counting Russia), actually ranks last in terms of specific indicators. In Russia, the north of the European part is characterized by insufficient resources for the total river flow (5-10 thousand m 3 /year/person), and the average value for the country is 29 thousand m 3 /year/person. is obtained at the expense of Asian territories, where the availability of water resources in sparsely populated areas reaches 50 thousand m 3 /year/person. A similar situation is observed, for example, in Brazil. The bulk of the country's water resources come from the Amazon River basin, which is very poorly developed economically. And densely populated central regions suffer from lack of moisture.

An important characteristic of the water resource potential of a territory is also the degree flow transitivity. That part of the annual river flow that is formed within the region under consideration is called the local component of the flow, in contrast to the part that may come from adjacent territories or go beyond its borders. For countries with arid climates, runoff transit often becomes a huge problem that hinders the development of production. For example, Sudan, on whose territory the main watershed of the Nile is located, according to an intergovernmental agreement with Egypt, has the right to use no more than 30% of the Nile River flow. For this purpose, Egypt, which is interested in guaranteed receipt of water and does not have a single tributary on its territory, with the help of a network of regime observations in Sudan (its former colony), exercises strict control over the passage of water on all tributaries of the Nile to determine the total emerging flow. In addition, all water use projects in Sudan are subject to control and approval. Therefore, for example, the project of the power plant currently being built by Sudan in Merowe is forced to include the slow filling of the reservoir, allowing Sudan to fit into the 30% limit along with other types of water use. Economically, this is not very profitable, because... will delay the start of operation of a power plant, the turbines of which can begin to operate only at a certain water pressure, determined by the height of the reservoir’s filling. Among the CIS countries, Uzbekistan (9%), Moldova (7.7%), Ukraine (24%), Azerbaijan (28%) have limited local water resources. In Russia, local water resources account for about 94% of the flow, in Georgia – 90%, Belarus – 61%, Kazakhstan – 55%.

In some regions, natural resources play a major role in providing water. lakes. Examples of lake countries are the countries of Fennoscandia, Canada, and the North-West of the European territory of Russia.

An important part of the water management complex of many countries are artificial ponds and reservoirs. Today in the world there are several tens of thousands of reservoirs of various sizes, purposes, and operating features. The area of ​​the water surface of the Earth's reservoirs is more than 400 thousand km 2, and their total volume is 6 thousand km 3. Large reservoirs have the greatest economic and environmental importance, however, small dams, small reservoirs and artificial lakes in some regions can play an important role, determining the features of environmental management in them (for example, Belarusian Polesie).

One of the most important sources of water supply is The groundwater, which are divided into soil (free-flowing) and artesian (under pressure between waterproof layers). In some cases, groundwater is used not only for water supply purposes, but also as a source of heat (thermal waters) and in medical practice (mineralized). Groundwater reserves are distributed very unevenly and are not equally easily accessible everywhere.

An important characteristic of the water resources of any large region should be considered the quantity precipitation. This is especially important for agricultural countries, because insufficient precipitation in the farming zone prevents the formation of water in the soil horizon in the required volume, which can negatively affect the development of agricultural production. For example, the peculiarities of the physical and geographical position of the CIS countries are such that the least precipitation falls in the agricultural zone. It is estimated that only 8% of the total precipitation falls over the plowing zone. Of course, these indicators vary greatly both over many years and within a year. But according to statistics, almost every third year in the steppe zone, and almost every year in the dry steppe zone, is dry.

An equally important characteristic of the local water resources regime, in addition to the spatial one, is its temporal variability. For example, large intra- and interannual variability of river flow makes it difficult to guarantee the consumption of water resources in regions with given levels of water volume used. This creates difficulties for stable water supply to the population and economic facilities, and therefore requires expensive measures to regulate and redistribute river flow. Therefore, from the point of view of economic value, the water resource potential of a territory depends, first of all, on the ratio of the volumes of surface and underground runoff. The surface component of the runoff is economically less valuable because it is more subject to seasonal and daily fluctuations. Water flow in the riverbed during the wet and dry seasons can differ by 2-3, and sometimes by 10 times. Rivers that are, for example, glacially fed are subject to sharp daily fluctuations in water flow. In addition, the surface component of the runoff is technically more difficult to master, because includes flood and flood waters that move very quickly along the riverbed. To capture them, it is necessary to create special regulatory devices (for example, the construction of reservoirs). In their absence, flood and hollow waters are not only not used, but can also pose a threat to the local population, as well as to various economic facilities. That is why a very important parameter for assessing the possibility of water development of a territory is such a parameter as sustainable flow component, which is quantitatively determined by the sum of the volume of underground flow and low-water channel flow (i.e., not including flood and hollow waters). On average for the world, it accounts for only 34% of the total runoff.

In addition, it should be borne in mind that the 20th century was characterized by significant anthropogenic changes in river flow. In inhabited areas there are practically no large rivers left that have not experienced the direct or indirect impact of economic activity. Moreover, the flow regime and water quality were equally significantly affected by activities both in the riverbeds themselves and in the catchment areas: urbanization (as a result of which hundreds of square kilometers of the surface of the catchment areas were covered with asphalt), agrotechnical and forest reclamation measures in the catchment areas, flow regulation a large number of reservoirs, various types of drainage and irrigation reclamation, significant water intakes for irrigation, industrial and municipal water supply, pollution of surface and groundwater, etc. In changes in the flow of rivers in Russia and neighboring countries, the role of individual anthropogenic factors has changed over time. Thus, in the 20th century, in the period before the 40th year, the main role was played by agrotechnical measures in watersheds (afforestation of slopes, creation of shelterbelts, etc.), in the 1950-1970s - channel flow regulation (this was the period of the creation of the largest reservoirs), later - water reclamation (drainage, watering, irrigation, etc.) took first place in importance.

It is now quite obvious that a significant transformation of the water regime, which was often abused (even if it was carried out in the interests of water supply), was the cause of not only a wide variety of environmental problems (such as salinization, waterlogging, flooding, reduction biological diversity, changes in the microclimatic characteristics of the territory, etc.), but also significantly complicated the satisfaction of the needs of water use and water consumption in the relevant regions. Therefore, it would be optimal to consider the implementation of a regional approach to solving water problems with adaptation to the local regime of water resources, without significantly changing it. Any region is characterized by its own specific regime and territorial distribution of water resources, therefore, approaches to the development of the water management complex must be individual.

The most important characteristic of water resources in any region is their quality. Unfortunately, the problem qualitative depletion of water resources, manifested in a reduction in the share of waters not polluted by humans, has become one of the most acute global problems humanity. In a number of areas there are practically no large rivers left whose water quality would not be affected by human economic activity. Already, many areas of the world are experiencing a shortage of clean water. The problem of access to clean water was actively discussed at the conference on sustainable development in Rio de Janeiro in 1992, where it was noted that in developing countries, every third person suffers from a lack of quality drinking water. Discussion of this problem was further developed in Johannesburg in 2002, where it was stated with regret that over the past 10 years the situation has not improved significantly, and in a number of regions, on the contrary, has worsened. According to the existing situation, pure water, and especially clean drinking water, is gradually turning into a market commodity, which is not always accessible to all categories of the population, especially in developing countries.

In connection with the problem of qualitative depletion of water resources, it is very relevant to determine the value of the water resource potential of the territory from the standpoint of assessing the ratio of the volumes of surface and underground runoff. Groundwater is several times less vulnerable to various types pollution than surface pollution, and therefore are a more valuable source of domestic and drinking water supply. First of all, this concerns rural areas, where wastewater treatment is usually not carried out adequately.

Water resource use and water management

The use of water resources in economic activities is carried out in the form of water use and water consumption. Water use- this type of activity when water is not removed from the reservoir, but is used to solve certain problems, being only a necessary condition for the functioning of a given sector of the economy. The largest water users are: water transport, recreation, timber rafting, hydropower, fisheries, etc. Water consumption- this is a type of activity in which water is actually a raw material, is removed from the reservoir and used in the technological process, becoming part of the final product or being lost irretrievably. The largest consumers of water are: food, chemical and other industries, municipal services, agriculture, etc. Requirements for water quality are different for different industries. The food and chemical industries have the highest requirements, and among water users, the fisheries industry. The requirements for water quality in the mining industry and timber rafting are not high.

Throughout the history of mankind, global volumes of water consumption have steadily increased almost in proportion to population growth because... water consumption increased for the needs of municipal supply, for the development of water-intensive industries, in the agricultural sector (primarily in irrigated agriculture). However, in the second half of the 20th century, there was a very sharp increase in the growth rate of water consumption, which, along with water pollution, actually led a number of regions of the world to the problem of acute water shortage. In total, during the period from 1900 to 1990, water consumption increased more than 10 times (from 400 to 4,100 km 3 per year), and for 2000, 10 years ago, it was predicted at 6 thousand km 3 per year. However, awareness of the limited water resources and the development of water-saving technologies made it possible to reduce forecast estimates at the beginning of the third millennium to volumes slightly lower than 4.8 thousand km 3 per year.

Of course, at the current level of development, humanity cannot reduce the amount of water used, so it is quite obvious that the projected reduction in water consumption can only be achieved by reducing the specific water intensity of production. In this regard, among the categories of water balance, the concepts of water intake and water consumption should be distinguished. Under water intake refers to the volume of water withdrawn for the needs of consumers from artificial or natural reservoirs. During use, part of the selected water is irretrievably lost through evaporation, seepage, and becomes bound in technological production processes. This volume of water included in the product, together with losses at all stages of the technological cycle, forms the so-called irrecoverable losses(gratuitous losses). Their value is maximum (80-90%) for agriculture, where water is mainly used for irrigation. However, in industry the demand for water is high. So, for the production of 1 ton synthetic fiber 5000 m 3 of water is required, 1 ton of cotton fabric - 250 m 3 of water, 1 ton of nickel - 4,000 m 3 of water. In agriculture, reducing losses is possible only on a limited scale, because can be implemented mainly by reducing irrigation rates, which is not always acceptable. As for industry, reducing losses is possible through greening production and improving technology. Currently, there are water supply systems of different levels of water intensity (Fig. 6.1). For example, direct-flow water supply systems are realized by supplying water to the enterprise directly from the source, then the used water is returned to the water supply source after purification or without it. In this case, it means the constant withdrawal of water from the reservoir in sufficiently large volumes. IN closed or recycled water supply systems in the production cycle of the enterprise, the same volume of water is repeatedly used after appropriate purification, which requires only additional water supply from a water source to compensate for the losses that occur, practically without the formation of discharged wastewater. This ensures a reduction in water intake volumes and a fairly high environmental friendliness of the production process. IN repeated or repeated water supply systems water used in some processes is transferred for subsequent use in other processes of the same or another enterprise, and then, after purification, is discharged into water bodies. Thus, in connection with the possibility of repeated use in production of volumes of withdrawn water, it is necessary to keep in mind that water consumption, i.e. the total volume of water used by an industry over a certain period of time can be significantly higher than water intake. First of all, this concerns industry.

Direct flow Closed Repeated

Fig.6.1. Technological water supply systems.

The water balance is largely determined water consumption structure, which is fundamentally different for countries with different economic specializations. Since most countries in the world are agricultural, most of the water consumed is in the agricultural sector of the economy (65%). Industry accounts for 20% of water consumption in the world, and public water supplies account for 11%. In Russia, the picture looks somewhat different: industry consumes 55% of all water, agriculture - 20%, and the domestic sector - 18%.

Municipal water supply, the share of which is relatively small in the world as a whole, plays a huge role in the life of society, being in fact an indicator of the level of social development. In recent decades, the share of water used for domestic needs has been constantly growing, which partly reflects the acceleration of urbanization processes in the world. Now the average city dweller uses 4 times more water than a rural resident. It is the municipal sector that places the highest demands on water quality and at the same time is the supplier of a significant part of the polluted water discharged into water bodies. For example, in Russia, more than 60% of the total volume of contaminated wastewater comes from the municipal sector. The volumes of municipal water supply vary greatly among different countries, cities and regions. So, for example, in London 260 liters of water are spent per inhabitant per day, in Paris - 300, in New York and Moscow - 600 liters each, for the CIS countries this value averages 450 liters per day per person. At the same time, there are countries where the consumption rate is only 15 - 20 liters per day, despite the fact that, according to the documents of the conference in Rio de Janeiro, the minimum value should not fall below 40 liters per day per person. Such indicators are simply unacceptable, because... Lack of clean drinking water is one of the main causes of infectious diseases. At the same time, according to the World Health Organization, more than 1.5 billion people are not sufficiently provided with clean drinking water.

In industrial production, water is used as a raw material, being part of manufactured products, as a solvent, a coolant, and as a medium that absorbs and transports impurities. Most of the water is used for cooling. For example, in thermal power engineering - more than 80% total flow. The bulk of water is used for the same purposes at metallurgical plants. Industry is one of the main suppliers of contaminated wastewater (in Russia, on average, about 30% of the total volume of wastewater). Despite the development of water recycling systems in industry, in some industries, for example in oil production and gas, an increase in water consumption is expected in the future (and in some cases has already been recorded), which is associated with the gradual complication of conditions for the development and operation of wells. In the structure of industrial water use in Russia, the leading role (70%) is clearly played by the electric power industry, which is associated with the use of a huge volume of water for cooling boilers in thermal power engineering and the operation of turbines in hydropower engineering. In second place is mechanical engineering (7%), followed by woodworking (4%) and other industries.

Agricultural water supply, which is the largest water consumer in the world, spends almost the entire volume of water used on watering irrigated lands. And only less than 10% of all water goes to the needs of livestock farming, municipal water supply to agricultural settlements and enterprises for processing agricultural products. However, it should be kept in mind that water withdrawn for livestock needs must meet the requirements for water used for domestic and drinking purposes, because for example, feeding livestock with contaminated water reduces animal productivity by 40-70%. In southern countries, water is also widely used to irrigate pastures, which, as a rule, have limited water resources and are the basis for the development of livestock farming.

The most important direction in the use of water resources is the use of its hydropower potential, which is characteristic mainly of flowing water. The main functions of hydroelectric power plants are regulating the uniformity of daily load schedules on energy systems (since covering peak loads with the help of thermal units is impractical and not always possible for technical and economic reasons, but is quite feasible with the help of turbines of hydroelectric power plants) and performing emergency reserve functions. The presence of regulating reservoirs at hydroelectric power plants greatly increases their capabilities, since it removes dependence on the water content of the river in a given period, allows for not only daily, but also weekly, seasonal and even long-term regulation of flow, and therefore increases the guaranteed capacity of hydroelectric power stations, creates conditions for optimal operating mode of thermal power plants. IN different countries The share of hydroelectric power plants in the total volume of electricity produced varies greatly: in Norway it accounts for 99.5%, in Brazil - 92.5%, New Zealand - 80.1%, Chile - 65.3%, France -15%, Russia – 21.2%, Australia – 9.6%, USA – 9%, Japan – 8.6%, UK – 1.4%, South Africa – 0.3%, Denmark – 0.1%. The level of development of hydropower potential is also very differentiated: more than 90% has been developed in France, Switzerland, Austria, 65-90% in Japan, Germany, Sweden, 45-65% in the USA, Canada, Brazil, Spain, 20-45% in China, India, Argentina. The world's largest hydroelectric power station will most likely be the Three Gorges hydroelectric power station on the Yangtze River (China) with a design capacity of 18.2 million kW, which should be fully operational by 2009. Russian hydroelectric power stations Sayano-Shushenskaya (6.4 million kW), Krasnoyarsk (6.0 million kW), Bratsk (4.5 million kW), Ust-Ilimskaya (4.3 million kW) occupy fifth and sixth places, respectively. , ninth and tenth most powerful in the world. The total capacity of hydroelectric power stations in Russia is 44 million kW (20% of power station capacity).

The most important element ensuring the effective functioning of the water sector of any country or region, in addition to natural water bodies, are specially created water management complexes and systems. As a rule, they include one or more waterworks and reservoirs (with all associated structures) located in one or more river basins, interconnected. An example of a water management complex can be waterworks and reservoirs on the Volga (for example, Kuibyshevsky), and a water management system can be cascades of waterworks and reservoirs (on the Colorado, Missouri, Volga, Angara, Dnieper rivers, etc.). The Moscow water management complex (system) is formed by fourteen waterworks and reservoirs on the Volga, Vazuza, Moscow rivers and the Moscow Canal. The types of water management complexes, their composition, number and role of participants (i.e. economic sectors related to the use of water resources) are different and depend on the geographical conditions and characteristics of the regional economy. Increasing the number of participants in the water management complex does not always increase its economic efficiency. This is explained by the fact that their requirements for the functioning of the complex (the level regime of the upper and lower reservoirs of hydroelectric complexes, timing, costs and volumes of releases, etc.) may be in sharp contradiction (for example, contradictions between energy and water transport, fishing and rural farming, etc.). Despite this and a number of environmental problems arising in connection with the construction and operation of water management complexes, they are capable of increasing the efficiency of water resource use, ensuring regulation and territorial redistribution of flow, and protecting against the destructive effects of water. Currently, more than 40 thousand reservoirs are in operation in the world, and the volumes of transferred river flow are colossal (in Canada alone, up to 140 km3 of water per year). In Russia and neighboring countries, up to 110 km3 of water is transferred per year, the length of the main canals exceeds 5 thousand km, and their total throughput capacity is 7.5 thousand m3 per second, the length of artificial waterways used by water transport is over 21 thousand km, the total length of the dams is 10 thousand km, the area of ​​fishery ponds exceeds 200 thousand hectares. For inter-basin flow redistribution, 37 large systems are used in Russia alone.

The meaning of water. Use of water resources

Chemically pure water does not occur in nature. The composition of water usually includes at least 18 substances, including dissolved gases and salts, suspended solids and liquid substances, determining taste, smell, color and other properties.

Of all liquids, water serves as the best solvent and has the highest heat capacity. Living organisms cannot do without water. It is part of the cells and tissues of all animals (75% of their total mass) and plants (about 90% of their total mass). The most complex reactions in plant and animal organisms can only occur in an aquatic environment. The human digestion process requires 9-10 liters of water per day. Loss of 10-20% of water by an animal leads to death. The role of water in plant photosynthesis is especially important. In the biomass of Earth's organisms, the volume of water reaches 1.1 thousand km 3 .

World water consumption is trending upward. The needs of the planet's population consume 7-8 km 3 of water per day. Natural waters are used in economic activities in the following areas: drinking water supply, food industry, domestic water supply, recreation, tourism, sports, livestock needs, pond fish farming, rain-fed and irrigated agriculture, industrial and thermal power water supply, hydropower, shipping.

Water use is divided into water use And water consumption. The water user does not take water from a natural source (river, reservoir), but only uses it for various purposes without changing the quantity. These are, first of all, hydropower, shipping, timber rafting, fisheries, and recreation. A water consumer, taking water from a source, returns it to a river or reservoir, usually in smaller quantities and of a different quality (water supply).

All types of economic activities can be divided into 2 groups:

activities carried out directly on water bodies(creation of ponds and reservoirs, construction of dams, flow transfer, etc.);

activities within the catchment(cutting down and planting forests, draining swamps, plowing land, using fertilizers, draining stormwater from industrial sites, urban areas, settlements, etc.).

The economic activities of the first group have a greater influence on the quantitative characteristics of water resources, and the second - on the qualitative ones.

In terms of water availability, Belarus is in relatively favorable conditions. Own resources are quite sufficient to meet water needs. The structure of total water intake is dominated by groundwater, whose share currently amounts to about 65%. In Belarus, the total water intake from natural sources(underground and surface) increased until 1991, and in the last 14-15 years there has been a steady decline, which can be partly explained by rational use natural resources, their payment, as well as restructuring in production sector countries after the collapse of the USSR.

The main water consumers in the country are housing and communal services and industry (75% of total water consumption). Large-scale industry and thermal power engineering are provided primarily by river waters, and the public utility needs of the population and the needs of food and light industry enterprises are provided by groundwater (more than 30 thousand artesian wells are operated).

2.1 Municipal, industrial and agricultural water supply

Communal water supply. The share of municipal water supply in the total volume of water consumed both in the world and in Russia is relatively small, but it is of decisive importance for the life of society. Lack of clean drinking water is one of the main causes of severe infectious diseases. More than half of the world's population uses water that does not meet sanitary and hygienic requirements.

In Russia, with regard to municipal water supply, the highest security indicator has been adopted - 97% in terms of the number of uninterrupted years. Municipal water supply is designed to satisfy the population's needs for water, therefore very high demands are placed on its quality, both in terms of physical properties and chemical and bacteriological indicators. To bring the quality of water into compliance with sanitary and hygienic standards, it is filtered, coagulated, chlorinated or fluoridated for disinfection, and enriched with ammonia to improve taste.

Standards for domestic and drinking water supply depend on the improvement of the housing stock of the settlement, climatic, and often historical conditions. Water consumption per person ranges from 30-50 to 400 l/day or more. Fluctuations in water consumption abroad are also significant. So in London there are 260 liters per person per person, and in New York - 600 liters per day. On average in Russia, urban water consumption is estimated at 450 l/day, of which 50% goes for household and drinking water, 20% for municipal water use and 30% for industrial needs. In many small towns and villages, specific water consumption is 1.5-2 times lower than the national average.

About 60% of water for public water supply is taken from surface and slightly more than 40% from underground sources, which have the best water quality due to their minimal pollution chemicals chemicals and pathogenic microbes.

Further improvement of water use in public utilities requires a number of measures, among which should be mentioned: centralized water supply in the coming years to the entire urban population (currently 98% of cities and 86% of urban-type settlements); worldwide savings and reduction of drinking water losses; stabilization of specific water consumption; development and implementation of improved water supply and distribution systems; a significant increase in the level of mechanization and automation of technological processes of water use.

Water supply for industry. Industry is one of the largest consumers of water. Different industries have different requirements for water quantity and quality. Thus, the production of 1 ton of cotton fabric consumes about 250 m3 of water, 1 ton of synthetic fiber - 2500-5000 m3. The chemical industry requires a lot of water: about 1000 m3 of water is used in the production of 1 ton of ammonia and 2000 m3 - 1 ton of synthetic rubber. Non-ferrous metallurgy is also a water-intensive consumer: 1 ton of nickel consumes 4,000 m3 of water. It should be borne in mind that at enterprises of the same industry, depending on the technological level of production, different amounts of water are used to produce 1 ton of product; for example, to produce 1 ton of oil, from 0.1 to 50 m3 of water is required. Typically, water consumption at related enterprises differs by 5-10 times.

Industrial water supply systems pay great attention to the volume of water consumed. With a direct-flow system, water from water supply sources is supplied to the enterprise, and after use and purification, and sometimes without it, it is returned to the source. In recycling water supply systems, water after the technological process is cooled, purified and then sent back to production cycle. The system is periodically replenished with fresh water to compensate for losses. In a repeated water supply system, water used in some processes is transferred for use in other processes of the same or other enterprises and then, after appropriate treatment, is discharged into water bodies. Often two latest systems are combined. Irreversible water consumption in industry is most often small and ranges from 2 to 20% depending on the nature of production and the technology used, and only in rare cases, such as in the oil refining industry, reaches 50%. Irreversible water consumption consists of the volume of water included in the product and losses at all stages of the technological process.

Water in industrial production is used as a raw material and solvent. The coolant, finally, is a medium that absorbs and transports dissolved impurities. Most of it is used in industry for cooling: for example, in thermal power engineering - 85% of the total consumption; The bulk of water is used for the same purposes at metallurgical plants.

Despite the widespread introduction of recycled water supply - on average up to 75%, and in some industries even more, industry annually withdraws about 50 km3 of water from water bodies, including approximately 4 km3 of sea water. Industrial enterprises annually discharge over 30 km3 of water into water bodies, while only about half of the discharged water is subjected to all types of treatment (mechanical, biological and physico-chemical), and approximately 5-7% of water is discharged without treatment at all.

In the context of the planned acceleration of the development of industrial production, the implementation of measures aimed at improving the use of water resources becomes important. The most important among these measures are the following: standardization of the quantity and quality of water consumed in various industries per unit of production; further expansion of the capacity of recycling water supply systems and closed water supply systems and closed water use systems; use of treated municipal wastewater in a number of industries; worldwide reduction in water leakage; recycling of sediments in wastewater from industrial enterprises and their processing for further use in the national economy.

It should be borne in mind that along with a reduction in the specific consumption of fresh water in some industries, such as oil and gas, in the future the consumption will increase, as the conditions for the development and operation of wells become more complicated.

Agricultural consumption. The annual water consumption in rural areas in our country is about 12 km3. The main consumers of water are rural settlements, livestock farming, agricultural processing enterprises, as well as production areas for equipment maintenance.

A characteristic feature of water supply to rural settlements is large intra-daily unevenness, significant volumes of irrecoverable water consumption due to the poor development of sewerage systems and relatively low specific water consumption per capita - 30-100 l/day. In general, 33% of rural settlements have centralized water supply. Compared to municipal water supply in cities, the condition of water intake structures in rural areas is at a lower technical level.

Groundwater is mainly used for agricultural water supply. The use of surface water is widespread only in some regions of Russia - the Volga region, West Siberia and Far East (30-35%).

Livestock farming is a significant consumer of water in rural areas. Animal water consumption rates range from 2 l/day (lamb) to 200 l/day (cow). Water withdrawn for livestock needs must meet the same requirements as water used for domestic and drinking purposes. Drinking contaminated water to livestock reduces animal productivity by 40-70%. In the southern regions of the country, livestock farming cannot develop without watering vast pastures, which, as a rule, They have very limited water resources.

To improve agricultural water supply, the following is required: the introduction of centralized water supply and sanitation systems with biological wastewater treatment facilities; increasing recycling and reuse of water; thorough treatment of wastewater and its use for irrigation of agricultural crops; improvement of water intake from surface sources; desalination of mineralized waters; using solar and wind energy to lift water. Increasing the improvement of rural settlements and increasing the volume of agricultural products will inevitably lead to an increase in agricultural water supply and sanitation in the near future.

Moscow Open Social University

Faculty of Finance and Economics

Extramural

TEST

in the discipline: “Environmental Economics”

on the topic of: "Ecological and economic aspects of using

water resources"

2nd year students

Melnik Elena Ivanovna

Specialty: 060400 – finance and credit

Teacher:

Plan

Introduction

Water reserves on Earth are enormous; they form the hydrosphere - one of the powerful spheres of our planet. The hydrosphere is the most important element of the biosphere. It unites all the waters of the globe, including oceans, seas and surface waters of land. In a broader sense, the hydrosphere includes groundwater, ice and snow in the Arctic and Antarctica, as well as atmospheric water and water contained in living organisms.

The waters of the hydrosphere are in constant interaction; transitions from one type of water to another constitute a complex water cycle on the globe. The origin of life on Earth is associated with the hydrosphere, since water is capable of forming complex chemical compounds that led to the emergence of organic life, and then the formation of highly organized animal organisms.

Water ensures the existence of living organisms on Earth and the development of their life processes. It is part of the cells and tissues of any animal and plant.

The climate and weather on Earth largely depend and are determined by the presence of water spaces and the content of water vapor in the atmosphere. In complex interaction, they regulate the rhythm of thermodynamic processes excited by the energy of the Sun. Oceans and seas, due to the high heat capacity of water, serve as heat accumulators and are capable of changing the weather and climate on the planet. The ocean, dissolving atmospheric gases, is an air regulator.

Water finds the widest use in human activities. Water is a material used in industry and is part of various types of products and technological processes, acts as a coolant, and serves for heating purposes. The force of falling water drives the turbines of hydroelectric power plants. The water factor is decisive in the development and placement of a row industrial production. Water-intensive industries that rely on large sources of water supply include many chemical and petrochemical industries, where water serves not only as an auxiliary material, but also as one of the important species raw materials, as well as electric power, ferrous and non-ferrous metallurgy, some branches of the forestry, light and food industries. Water is widely used in the construction and building materials industry. Human agricultural activity is associated with the consumption of huge amounts of water, primarily for irrigated agriculture. Rivers, canals, lakes are cheap means of communication. Water bodies These are also places of recreation, restoration of people's health, sports, and tourism.

In this regard, the rational use of water resources and their protection have key value to achieve sustainable development.

1. Ecological and economic importance of water resources

Water masses on the surface of the Earth form a thin geological shell, which occupies most surface of the Earth and forms the World Ocean (361 million km3, or 70.8% of the entire surface of the planet). The total volume of the hydrosphere is 1.4 billion km3, its share in relation to the entire mass of the Earth does not exceed 0.02%. The bulk of the water in the hydrosphere is concentrated in the seas and oceans (94%), the second largest volume of water masses is occupied by groundwater (3.6%), ice and snow of the Arctic and Antarctic regions, and mountain glaciers (2%). Land surface waters (rivers, lakes, swamps) and atmospheric waters account for fractions of a percent of the total volume of water in the hydrosphere (0.4%).

Water is a chemical compound of hydrogen and oxygen (H2O), a colorless liquid without odor, taste or color. Under natural conditions, it always contains dissolved salts, gases and organic substances, their amount varies depending on the origin of the water and environmental conditions. When the salt concentration is up to 1 g/l, water is considered fresh, up to 24.7 g/l - brackish, above - salty.

Freshwater resources constitute a small proportion of the total volume of the entire hydrosphere, but they play a decisive role in the general circulation of water, in the connections of the hydrosphere with ecological systems, in human life and the existence of other living organisms, in the development of production. Fresh waters account for about 2% of the hydrosphere; the used part (river runoff, lake water) is less than 1% of the total volume of hydrosphere waters.

On average, water makes up about 90% of the mass of all plants and 75% of the mass of animals. Complex reactions in animal and plant organisms can only occur in the presence of an aqueous environment. The body of an adult contains 60-80% water. Physiological need a person in water can be satisfied only with water and nothing else. The loss of 6-8% of water is accompanied by a semi-fainting state, 10% - hallucination, 12% - leads to death.

With regard to human economic activity, the concept of “water resources” is introduced - these are all reserves of surface water suitable for economic use, including soil and atmospheric moisture. Surface water resources are determined mainly by the total runoff in an average year in terms of water availability. They are distributed and used unevenly across the Earth and individual regions.

The CIS countries have the world's largest water resources, in total they rank second in the world (after Brazil) in terms of average annual river flow, and they also have significant potential groundwater reserves. However, these resources are distributed extremely unevenly across the territory of the CIS countries, which is explained by different geographical, climatic, geological and hydrogeological conditions of individual regions.

Water distribution and consumption by continent

The total average annual flow volume is almost 4.7 thousand km 3, and the vast majority of it falls on Russian Federation- 4.27 thousand km 3 (more than 90%). Ukraine has significant water resources - 0.21 thousand km 3 (4.5%), Kazakhstan - 0.12 thousand km 3 (2.7%), Uzbekistan - 0.11 thousand km 3 (2.3%). ), Tajikistan - 0.1 thousand km 3 (2.0%).

The uneven distribution of runoff also corresponds to the different availability of water resources in the CIS countries. If the specific flow supply for the CIS countries as a whole is equal to 210 thousand km 3 per year per 1 km 2, then the highest in Georgia and Tajikistan are 877 and 667, respectively, and the lowest in Turkmenistan - 145 and in Kazakhstan - 46 thousand km 3 per year per 1 km 2.

2. Main directions of water resources use

In its development, humanity has gone through many stages in the use of water. Initially, the direct use of water prevailed - for drinking, for cooking, and for domestic economic purposes. The importance of rivers and seas for the development of water transport is gradually increasing. The emergence of many centers of civilization is associated with the presence of waterways. People used water spaces as routes of communication, for fishing, salt production and other types of economic activities. During the heyday of shipping, the most economically developed and wealthy were the maritime powers. And today, the use of waterways has a significant impact on the development of the world economy. Thus, maritime transport transports 3-4 billion tons of cargo per year, or 4-5% of the total volume of cargo transportation, while carrying over 30 trillion tons/km, or 70% of the total global cargo turnover.

In its development, humanity has gone through many stages inwater use. Initially, the direct use of water predominated - for drinking, for cooking, infor household economic purposes. The value gradually increasesthe development of rivers and seas for the development of water transport. Arosenewthe existence of many centers of civilization is associated with the presence of waterways. People used water spaces as routes of communication, for fishing, salt extraction and other types of economic activities.military activity. During the heyday of shipping, the mostThe sea powers were economically developed and rich. ANDToday the use of waterways is significantaffects the development of the world economy. Yes, seatransport transports 3-4 billion tons of cargo per year, or 4-5% of the totalvolume of cargo transportation, performing over 30 trillion. t/km,or 70% of the total world cargo turnover.

Distinctive featureXXArt. there was a rapid increase in water consumptionfucking in a variety of directions. First placeby volume of water consumption came out agricultural production. In order to provide food for everyoneThe growing population of the Earth requires the expenditure of huge amounts of water in agriculture. Moisture and heat resources and their relationshipswearing determine the natural biological productivityity in various natural and climatic zones of the world. Forproduction 1 kg plant mass different plants consumptionblow for transpiration from 150-200 to 800-1000 m 3 of water; athow 1 ha area occupied by corn evaporates during the growing seasonny period 2-3 million liters of water; for growing 1 ton of wheat,rice or cotton requires 1500, 4000 and 10,000 tons of water, respectivelyactually.

The area of ​​irrigated land on the globe currently reaches 220 million hectares. They provide approximately half of the world's agricultural products; up to 2/3 of the world's cotton crops are located on such lands. At the same time for irrigation 1 ha crops consume 12-14 thousand m 3 of water during the year. The annual water flow reaches 2500 km 3 or more than 6% of the total annual flow of the world's rivers. In terms of the volume of water used, irrigated agriculture ranks first among other water consumers.

The need for water is extremely high for modernlivestock farming, keeping livestock on farms and livestock breedingski complexes. For production 1 kg milk is wasted4 t, a 1 kg meat - 25 tons of water. Specific water use peragricultural and other purposes in various countries world (according to the 80-90sXXArt.) is given in table. 7.2.

Water consumption is growing inindustrial, production. It is impossible to indicate another substance that would finduses as varied and wide as water. She isis a chemical reagent involved in the production of acidoxygen, hydrogen, alkalis, nitric acid, alcohols and manyOther essential chemical products. Water is a necessary component in the production of building materials:ment, gypsum, lime, etc. The bulk of water in industriality is used for power generation and cooling.Significant amounts of water in the manufacturing industryity is used for dissolving, mixing, purifying andother technological processes. For smelting 1 ton of cast iron andconverting it into steel and rolled steel consumes 50-150m 3water,1 t copper - 500 m 3 , 1 t syntheticsome rubber and chemical fibers - from 2 to 5 thousand, m 3 of water.

Table 7.2

Use of water for various economic purposesV individual countries world (% of total water consumption)

* Including water use in fisheries.

The overwhelming number of industries are adapted to use only fresh water; the latest industries (production of semiconductors, nuclear technology, etc.) are notwater of special purity is used. Modern industrialenterprises and thermal power plants spend hugewater resources comparable to the annual flow of large rivers.

As populations and cities grow, the racewater flow for municipal and household needs. Physiological human need for water, which is introduced into the body with drink and food, depending on climatic conditions compoundflows 9-10 l/day. Much large quantity water is neededdimo for sanitary and household needs. Only whensufficient level of water consumption, which is ensuredcentralized water supply systems, it turns outit is possible to remove waste and sewage using a floating sewer. Level of domestic and drinking water consumptionvaries significantly: from 30-50 l/day. in buildings with water use from standpipes (without sewerage tion) up to 275-400 l/day. per inhabitant in buildings with water supplywater, sewerage and centralized hot water systemwater supply Naturally, improving communal living conditions in cities and rural areas entailsfight rising water consumption.

Theoretically, water resources are inexhaustible, since whenrational use they are continuously renewedin the process of the water cycle in nature. Still in the near futureshlom it was believed that there is so much water on Earth that, with the exception ofIn certain dry areas, people do not have to worry about running out of food. However, water consumption is growing at such a rate that humanity is increasingly faced withwith the problem of how to provide for future needs for it. INCountries and regions of the world are already experiencing a shortage of water resources, which is increasing every year.

Growth of industrial and agricultural productionIndeed, high rates of urbanization have contributed to the expansion of the use of water resources in Belarus. Fence of river and underearth's waters constantly increased, reaching its maximumnominal value equal to 2.9 km 3 in 1990 . As a result of the decline inproduction starting from 1992 . there is a decrease in water consumptionleniya in various sectors of the economy. IN 1999 . it amounted to1 7 km 3 . The main consumer of water turned out to be housing and communal services - 46.0% of total consumption; industrial (industrial) water supply - 31.5%; agriculturaldomestic water supply and irrigation -9,7 %; fish pondvoye economy - 12.8% (use of water resourceswife in table 7.3). In the regional aspect, the central part of Belarus stands out, where almost a third of the total volume is consumedwaters used, which basically coincides with the economicpotential of this region.

Table 7.3

Use of water resources in the Republic of Belarus

Waterfarming is being formed as an industryeconomy, engaged in the study, accounting, planninge and forecasting the integrated use of waterresources, protection of surface and groundwater from pollutiondepletion and depletion, transporting them to the place of consumption.The main task of the water industry is to provide all sectors and types of economic activities with water as needed.quantity and appropriate quality.

According to the nature of the industry’s use of water resources,households are divided into water consumers and water userstel. AtwaterO -consumption water is withdrawn from its usesources (rivers, reservoirs, aquifers) and is usedin industry, agriculture, for municipal and domestic needs; it is included in the manufactured products,exposed to contamination and evaporation. Water consumption fromwater resource use points of view are divided intoon returnable(returned to source) andirrevocable ( losses).

Water use It is usually associated with processes where it is not water as such that is used, but its energy or the aquatic environment.Hydropower and water transport are developing on this basis.port, fisheries, recreation and sports system, etc.

Sectors of the national economy make demands on water resourcesitself has different requirements, so the water management builderIt is most advisable to solve this problem comprehensively, taking into account the characteristics of each industry and those changes in the regime of underground andsurface waters that arise during construction guiderotechnical structures and their operation and violate the ecological systems. Integrated use of water resourcesresources allows you to most rationally satisfy needs ..