Water plays an exceptional role in maintaining the vital functions of any organism. This substance can be presented in three states of aggregation: solid, liquid and gaseous. But it is liquid that is the main internal environment of the human body and other organisms, because All biochemical reactions take place here, and it is in it that all cell structures are located.
What percentage of the earth is water?
According to some estimates, about 71% of the total is water. It is represented by oceans, rivers, seas, lakes, swamps, icebergs. Atmospheric air vapors are also considered separately.
Of this total, only 3% is fresh water. Most of it is found in icebergs, as well as in rivers and lakes on continents. So what percent of the water on Earth is in the seas and oceans? These pools are where salty H2O accumulates, which accounts for 97% of the total volume.
If it were possible to collect all the water on earth into one drop, then the sea water would occupy a volume of approximately 1,400 million km 3, and the fresh water would accumulate into a drop with a volume of 10 million km 3. As you can see, there is 140 times less fresh water on Earth than salt water.
What percentage does it occupy on Earth?
About 3% of the total liquid is fresh water. Most of it is concentrated in icebergs, in mountain snow and groundwater, and only a small amount is found in the rivers and lakes of the continents.
Actually, fresh water is divided into accessible and inaccessible. The first group consists of rivers, swamps and lakes, and also includes layers of the earth's crust and atmospheric air vapor. Man has learned to use all this for his own purposes.
What percentage of fresh water on Earth is considered inaccessible? First of all, these are large reserves in the form of icebergs and mountain snow covers. They make up the majority of fresh water. Also, the deep waters of the earth's crust form a significant part of all fresh H2O. People have not yet learned to use either source, but there is great benefit in this, because people cannot yet competently manage such an expensive resource as water.
in nature
Fluid circulation plays an important role for living organisms, because... water is a universal solvent. This makes it the main internal environment of animals and plants.
Water is concentrated not only in the human body and other creatures, but also in water basins: seas, oceans, rivers, lakes, swamps. The fluid cycle begins with precipitation such as rain or snow. The water then accumulates and then evaporates under the influence of the environment. This is clearly noticeable during periods of drought and heat. The circulation of liquid in the atmosphere determines what percentage of water on earth is concentrated in solid, liquid and gaseous states.
The cycle is of great ecological importance because liquid circulates in the atmosphere, hydrosphere and earth's crust, and thereby purifies itself. In some reservoirs, where the level of pollution is quite high, this process is of enormous importance for maintaining the vital functions of ecosystem organisms, but restoring the previous “purity” takes a long period of time.
Origin of water
The riddle of how the first water appeared has not been solved for a long period of time. However, several hypotheses have appeared in the scientific community that offer options for the formation of liquid.
One of these guesses dates back to the time when the Earth was just in its infancy. It is associated with the fall of “wet” meteorites, which could bring water with them. It accumulated in the bowels of the Earth, which gave rise to the primary hydration shell. However, scientists cannot answer the question of what percentage of water the Earth contained at that distant time.
Another theory is based on the terrestrial origin of water. The main impetus for the formation of this hypothesis was the discovery of a relatively high concentration of heavy hydrogen deuterium in the seas and oceans. The chemical nature of deuterium is such that it could only be formed on Earth by increasing atomic mass. Therefore, scientists believe that the liquid was formed on Earth and is not of cosmic origin. However, researchers who support this hypothesis still cannot answer the question of what percentage of water there was on Earth 4.4 billion years ago.
More than 98% of all water resources of the Earth are salty waters of the oceans, seas, etc. The total volume of fresh water on Earth is 28.25 million km3, or about 2% of the total volume of the hydrosphere. The bulk of fresh water is concentrated in glaciers, the waters of which are still used very little. The rest of the fresh waters suitable for water supply account for 4.2 million km3 of water, or only 0.3% of the volume of the hydrosphere.
The hydrosphere plays a huge role in shaping the natural environment of our planet. It also very actively influences atmospheric processes (heating and cooling of air masses, saturating them with moisture, etc.).
Atmosphere ( Greek “atmos” steam) gas shell of the Earth, consisting of a mixture of various gases, water vapor and dust (Table 6.3, according to N. Reimers, 1990). The total mass of the atmosphere is 5.15 1015 tons. At an altitude of 10 to 50 km, with a maximum concentration at an altitude of 20–25 km, there is an ozone layer that protects the Earth from excessive ultraviolet irradiation, which is fatal to organisms.
Table 6.3
Atmospheric composition
The atmosphere physically, chemically and mechanically affects the lithosphere, regulating the distribution of heat and moisture. Weather and climate on Earth depend on the distribution of heat, pressure and water vapor content in the atmosphere. Water vapor absorbs solar radiation, increases air density, and is the source of all precipitation. The atmosphere supports various forms of life on Earth.
In the formation of the Earth’s natural environment, the role of the troposphere (the lower layer of the atmosphere up to a height of 8–10 km in polar, 10–12 km in temperate and 16–18 km in tropical latitudes) and, to a lesser extent, the stratosphere, a region of cold rarefied dry air with a thickness of approximately 20 km. Meteorite dust continuously falls through the stratosphere, volcanic dust is ejected into it, and in the past, products of nuclear explosions in the atmosphere.
In the troposphere, global vertical and horizontal movements of air masses occur, which largely determine the water cycle, heat exchange, and transboundary transport of dust particles and pollution.
Atmospheric processes are closely related to processes occurring in the lithosphere and water shell.
Atmospheric phenomena include: precipitation, clouds, fog, thunderstorm, ice, dust (sand) storm, squall, blizzard, frost, dew, hoarfrost, icing, aurora, etc.
The atmosphere, hydrosphere and lithosphere closely interact with each other. Almost all surface, exogenous, geological processes are caused by this interaction and take place, as a rule, in the biosphere.
Biosphere the outer shell of the Earth, which includes part of the atmosphere up to a height of 25–30 km (up to the ozone layer), almost the entire hydrosphere and the upper part of the lithosphere to a depth of approximately 3 km. The peculiarity of these parts is that they are inhabited by living organisms that make up the living matter of the planet. The interaction of the abiotic part of the biosphere - air, water and rocks, and organic matter - biota, determined the formation of soils and sedimentary rocks. The latter, according to V.I. Vernadsky, bear traces of the activity of ancient biospheres that existed in past geological eras.
19. World water resources
The concept of water resources can be interpreted in two senses – broad and narrow.
In a broad sense, this is the entire volume of water in the hydrosphere contained in rivers, lakes, glaciers, seas and oceans, as well as in underground horizons and in the atmosphere. The definitions huge, inexhaustible are quite applicable to it, and this is not surprising. After all, the World Ocean occupies 361 million km2 (about 71% of the total area of the planet), and glaciers, lakes, reservoirs, swamps, and rivers account for another 20 million km2 (15%). As a result, the total volume of the hydrosphere is estimated at 1390 million km3. It is not difficult to calculate that with such a total volume, each inhabitant of the Earth now has approximately 210 million m3 of water. This amount would be enough to supply a large city for a whole year!
However, it is necessary to take into account the possibilities of using these enormous resources. Indeed, of the total volume of water contained in the hydrosphere, 96.4% falls on the share of the World Ocean, and of the water bodies on land, the largest amount of water contains glaciers (1.86%) and groundwater (1.68%), the use of which is possible, but more partly very difficult.
That is why, when we talk about water resources in the narrow sense of the word, we mean fresh water suitable for consumption, which constitutes only 2.5% of the total volume of all waters in the hydrosphere. However, significant adjustments must be made to this indicator. One cannot ignore the fact that almost all fresh water resources are “conserved” either in the glaciers of Antarctica, Greenland, mountainous regions, in the ice of the Arctic, or in groundwater and ice, the use of which is still very limited. Lakes and reservoirs are used much more widely, but their geographical distribution is by no means ubiquitous. It follows that the main source of meeting humanity’s needs for fresh water has been and remains river (channel) water, the share of which is extremely small, and the total volume is only 2100 km3.
This amount of fresh water would not be enough for people to live by now.
However, due to the fact that the duration of the conditional moisture cycle for rivers is 16 days, during the year the volume of water in them is renewed on average 23 times and, therefore, the river flow resources can be purely arithmetically estimated at 48 thousand km3/year. However, the prevailing figure in the literature is 41 thousand km3/year. It characterizes the “water ration” of the planet, but reservations are also necessary here. It is impossible not to take into account that more than half of the channel waters flow into the sea, so that the resources of such waters actually available for use, according to some estimates, do not exceed 15 thousand km3.
If we consider how the total river flow is distributed between large regions of the world, it turns out that foreign Asia accounts for 11 thousand km3, South America - 10.5, North America - 7, CIS countries - 5.3, Africa – 4.2, for Australia and Oceania – 1.6 and for foreign Europe – 1.4 thousand km3. It is clear that behind these indicators are, first of all, the largest river systems in terms of flow: in Asia - the Yangtze, Ganges and Brahmaputra, in South America - the Amazon, Orinoco, Parana, in North America - the Mississippi, in the CIS - the Yenisei, Lena, in Africa - Congo, Zambezi. This fully applies not only to regions, but also to individual countries (Table 23).
Table 23
TOP TEN COUNTRIES BY SIZE OF FRESHWATER RESOURCES
Figures characterizing water resources cannot yet give a complete picture of water availability, since the provision of total flow is usually expressed in specific indicators - either per 1 km2 of territory or per inhabitant. This water supply of the world and its regions is shown in Figure 19. Analysis of this figure suggests that with a global average of 8000 m3/year, Australia and Oceania, South America, the CIS and North America have indicators above this level, and below - Africa and foreign Europe and overseas Asia. This situation with water supply in the regions is explained both by the overall size of their water resources and by the size of their population. No less interesting is the analysis of differences in water availability in individual countries (Table 24). Of the ten countries with the greatest water availability, seven are located within the equatorial, subequatorial and tropical zones, and only Canada, Norway and New Zealand are within the temperate and subarctic zones.
Rice. 19. Availability of river flow resources in major regions of the world, thousand m3/year
Table 24
COUNTRIES WITH THE HIGHEST AND LEAST AVAILABILITY OF FRESHWATER RESOURCES
Although based on the above per capita indicators of water availability for the whole world, its individual regions and countries, it is quite possible to imagine its general picture, it would be more correct to call such availability potential. To imagine the real water availability, you need to take into account the size of water intake and water consumption.
World water consumption in the twentieth century. grew as follows (in km3): 1900 – 580, 1940 – 820, 1950 – 1100, 1960 – 1900, 1970 – 2520, 1980 – 3200, 1990 – 3580, 2005 - 6000. These general indicators of water consumption are very important: they indicate that throughout the 20th century. global water consumption increased 6.8 times. Already, almost 1.2 billion people do not have access to clean drinking water. According to the UN forecast, universal access to such water can be achieved: in Asia - by 2025, in Africa - by 2050. The structure, i.e., the nature of water consumption, is no less important. Nowadays, 70% of fresh water is consumed by agriculture, 20% by industry, and 10% goes to meet domestic needs. This ratio is quite understandable and natural, but from the point of view of saving water resources, it is quite unprofitable, primarily because in agriculture (especially in irrigated agriculture) irrecoverable water consumption is very high. According to available estimates, in 2000
Distribution of water resources on the planet
irrecoverable water consumption in agriculture in the world amounted to 2.5 thousand km3, while in industry and public utilities, where recycled water supply is more widely used, only 65 and 12 km3, respectively. From all that has been said, it follows, firstly, that today humanity already uses quite a significant part of the planet’s “water ration” (about 1/10 of the total and more than 1/4 of the actually available) and, secondly, that irreversible water losses amount to more than 1/2 of its total consumption.
It is no coincidence that the highest rates of per capita water consumption are characteristic of countries with irrigated agriculture. The record holder here is Turkmenistan (7000 m3 per person per year). It is followed by Uzbekistan, Kyrgyzstan, Kazakhstan, Tajikistan, Azerbaijan, Iraq, Pakistan, etc. All these countries are already experiencing a significant shortage of water resources.
In Russia, the total river flow reaches 4.2 thousand km3/year, and, therefore, the resource availability of this flow per capita is 29 thousand m3/year; This is not a record, but quite a high figure. Total fresh water intake in the second half of the 1990s. Due to the economic crisis, there was a tendency to decrease slightly. In 2000 it was 80–85 km3.
The structure of water consumption in Russia is as follows: 56% goes for production, 21% for household and drinking needs, 17% for irrigation and agricultural water supply, and 6% for other needs. It is easy to calculate that in Russia as a whole, the total water intake is only 2% of the total river flow resources. However, this is an average figure, and in some river basins it reaches 50–75% or more. The same applies to individual economic regions of the country. Thus, in the Central, Central Chernozem and Volga regions, water availability per capita is only 3000–4000 m3/year, and in the Far East – 300 thousand m3.
The general trend for the whole world and its individual regions is a gradual decrease in water availability, so various ways to save water resources and new ways of water supply are being sought.
Date: 2016-04-07
How much fresh water is left on the planet?
Life on our planet originated from water, the human body consists of 75% water, so the issue of fresh water reserves on the planet is very important. After all, water is the source and stimulant of our life.
Fresh water is considered to be water that contains no more than 0.1% salt. Moreover, it does not matter what state it is in: liquid, solid or gaseous.
World fresh water reserves
97.2% of the water that is on planet earth belongs to salty oceans and seas. And only 2.8% is fresh water. On the planet it is distributed as follows:
- 2.15% of water reserves are frozen in the mountains, icebergs and ice sheets of Antarctica;
- 0.001% of water reserves are in the atmosphere;
- 0.65% of water reserves are in rivers and lakes. This is where people take it for their consumption.
In general, it is believed that fresh water sources are endless. Because the process of self-healing constantly occurs as a consequence of the water cycle in nature. Every year, as a result of the evaporation of moisture from the world's oceans, a huge supply of fresh water (about 525,000 km3) is formed in the form of clouds. A small portion does end up back in the ocean, but most falls on the continents in the form of snow and rain and then ends up in lakes, rivers and groundwater.
Freshwater consumption in different parts of the planet
Even such a small percentage of available fresh water could meet all the needs of humanity if its reserves were evenly distributed throughout the planet, but this is not the case.
The Food and Agriculture Organization of the United Nations (FAO) has identified several areas whose water consumption levels exceed the amount of renewable water resources:
- Arabian Peninsula. For public needs, five times more fresh water is used here than is available in available natural sources. Water is exported here using tankers and pipelines, and seawater desalination procedures are carried out.
- Water resources in Pakistan, Uzbekistan and Tajikistan are under stress. Almost 100% of renewable water resources are consumed here. More than 70% of renewable water resources are produced by Iran.
- Freshwater problems also exist in North Africa, especially in Libya and Egypt. These countries use almost 50% of water resources.
The greatest need is not in countries with frequent droughts, but in those with high population densities. You can see this using the table below. For example, Asia has the largest area of water resources and Australia the smallest. But at the same time, every resident of Australia is provided with drinking water 14 times better than any resident of Asia. This is because Asia has a population of 3.7 billion, while Australia has only 30 million.
Problems of fresh water use
Over the past 40 years, the amount of clean fresh water per person has decreased by 60%. Agriculture is the largest consumer of fresh water. Today, this sector of the economy consumes almost 85% of the total volume of fresh water used by humans. Products grown using artificial irrigation are much more expensive than those grown on soil and irrigated by rain.
More than 80 countries around the world experience a shortage of fresh water. And every day this problem is becoming more acute. Water scarcity even causes humanitarian and government conflicts. Improper use of groundwater leads to a decrease in its volume. Every year these reserves are depleted by 0.1% to 0.3%. Moreover, in poor countries, 95% of water cannot be used for drinking or food at all due to high levels of pollution.
The need for clean drinking water increases every year, but its quantity, on the contrary, is only decreasing. Almost 2 billion people have limited water consumption. According to experts, by 2025, almost 50 countries of the world, where the number of inhabitants will exceed 3 billion people, will experience the problem of water shortage.
In China, despite high rainfall, half the population does not have regular access to sufficient drinking water.
Distribution of waters on Earth
Groundwater, like the soil itself, is renewed too slowly (about 1% per year).
The issue of the greenhouse effect remains relevant. The climate condition of the Earth is constantly deteriorating due to the constant release of carbon dioxide into the atmosphere. This causes an abnormal redistribution of atmospheric precipitation, the occurrence of droughts in countries where they should not occur, snowfall in Africa, high frosts in Italy or Spain.
Such abnormal changes can cause a decrease in crop yields, an increase in plant diseases, and an increase in the population of pests and various insects. The planet's ecosystem is losing its stability and cannot adapt to such a rapid change in conditions.
Instead of results
In the end, we can say that there are enough water resources on planet Earth. The main problem with water supply is that these supplies are unevenly distributed on the planet. Moreover, 3/4 of fresh water reserves are in the form of glaciers, which are very difficult to access. Because of this, some regions are already experiencing a shortage of fresh water.
The second problem is the contamination of existing accessible water sources with human waste products (salts of heavy metals, petroleum products). Clean water that can be consumed without preliminary purification can only be found in remote ecologically clean areas. But densely populated regions, on the contrary, suffer from the inability to drink water from their meager supplies.
Water resources include all usable surface and underground waters of the Earth. Water is necessary to maintain organic life on Earth, human existence, and economic activities. The water factor has a great influence on the location of social production. Water-intensive industries with a focus on large sources of water supply include many industries (electric power, ferrous and non-ferrous metallurgy, pulp and paper, chemical industry, etc.), agriculture (rice growing, cotton growing, etc.). Water resources are an extremely important factor not only for obviously water-intensive industries, but also for the development of cities and meeting the household needs of the population.
People's needs for fresh water are especially great, the reserves of which are limited on Earth. The total water reserves on Earth, forming its hydrosphere (oceans and seas, rivers, lakes, swamps and reservoirs, groundwater, glaciers and snow, soil moisture and atmospheric vapor), are estimated at 1,386 million cubic meters. km. Of these, 96.5% of water resources come from the salty waters of the World Ocean and 1% from salty groundwater. The remaining 2.5% of the volume of the hydrosphere constitutes the fresh water resources on the globe.
However, in reality their number is much smaller (only 0.3% of the volume of the hydrosphere), since polar ice is practically not yet used as a source of fresh water.
Thus, despite the presence of enormous water resources on Earth, their quantity suitable for direct practical use (fresh water) is very limited.
Among the few sources of fresh water, rivers are the main ones. River water resources are renewable and inexhaustible, unlike underground fresh water, whose reserves are exhaustible. The amount of annually renewable water resources is estimated by the size of river flow, which depends on the relationship between precipitation (falling in the form of rain and snow on the surface of the river basin) and evaporation of the fallen moisture.
River water resources (river flow resources) are estimated at 47 thousand cubic meters. km per year, and the world average river flow (flow per capita) is about 8 thousand cubic meters. m/year.
More than half of the fresh water resources from the planet's river flows are in Asia (13,190 cubic km per year), where such large rivers of the Earth as the Yangtze, Irawad, Mekong, Ganges, Brahmaputra, and South America flow (10,380 cubic km/ year) with its greatest river (by flow volume, basin area, length and width) the Amazon. The other half of the total volume of river flow is shared between North America (5,960), Africa (4,225), Europe (3,110), Australia and Oceania (1,965 cubic km/year). Australia and Oceania, which are in last place on this list, at the same time have the highest water supply per capita (83 thousand cubic meters / year), and Asia, which leads in fresh water reserves, has the lowest average water supply per capita - 4.5 thousand cubic meters m/year. In South America this figure is 34 thousand cubic meters. m/year, in Northern - 15, in Africa - 6.5, in Europe — b thousand cubic meters m/year. Water availability varies significantly across countries around the world. Russia has significant fresh water resources. The total volume of its river flow is estimated at 4,270 cubic meters. km/year, which is about 10% of the total flow of all rivers in the world. According to this indicator, following Brazil, Russia surpasses all countries in the world. Russia's water supply per capita (28.5 thousand cubic meters/year) is more than three times higher than the world average. Water resources within the country are distributed extremely unevenly - about 70% of its total surface flow falls on sparsely populated, economically underdeveloped regions of Siberia and the Far East, and only 30% - on densely populated and most water-intensive regions of the European part and the Urals.
Distribution of water on Earth and its cycle. Water balance
The worst provision of water is in the central (Lipetsk, Belgorod, Kursk and Voronezh regions) and southern (Rostov, Astrakhan regions, Republic of Kalmykia, etc.) regions of the European part.
In Russia there are about 120 thousand.
rivers (over 10 km long), most of them belong to the basins of the Arctic (Northern Dvina, Pechora, Ob with Irtysh, Yenisei, Lena, Indigirka, Kolyma, etc.), Pacific (Amur, Anadyr, Penzhina, etc.) and Atlantic (Don, Kuban, Neva) oceans. One of the largest and most abundant rivers in Russia, the Volga belongs to the internal drainage basin and flows into the Caspian Sea. A significant volume of fresh water is contained in reservoirs (of which Bratskoye, Krasnoyarsk, Zeyskoye, Ust-Ilimskoye, Samara are among the largest in the world) and lakes (Baikal - the deepest lake in the world, Ladoga, Onega, Taimyr, etc.). Russia is also rich in fresh groundwater resources, the exploitable reserves of proven deposits amount to 27.3 cubic meters. km/year, of which 80% are located in the European part.
In general, water consumption in the world is constantly growing and in 2000 it amounted to 4,780 cubic meters. km, i.e. approximately 10% of the total freshwater resources (total annual flow) of the planet. The main consumers of water in the world are agriculture (69%), industry (21%), public utilities (6%) and reservoirs. At the same time, the share of water used in agriculture and municipal services is constantly increasing.
In Russia, about 100 cubic meters are used annually. km of fresh water (in the USA - 550 cubic km), or approximately 2.4% of its total annual river flow. In the structure of water consumption, in contrast to the world average, the leading role is played by industry (55%), the share of agriculture is low (20%) and the public sector is high (19%).
In recent years, many countries around the world have begun to experience a shortage of water resources, which is associated not with their depletion, but with the qualitative deterioration of natural surface waters - their pollution as a result of use in everyday life and in production. The volume of contaminated surface water is so large that the problem of clean water has become global.
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Usually, when asked what percentage of water is on Earth, they answer that 70.8% of the surface of our planet is covered with water. And this is true if we take into account only the ratio of the total area of the earth's surface (about 510 million sq. km) and the area of the World Ocean (360 million sq. km).
However, the World Ocean is not the entire hydrosphere of the Earth. 3.2% of the earth's surface is occupied by glaciers (16.3 million sq. km), 0.45% by lakes and rivers (2.3 million sq. km), 0.6% by swamps and heavily wetlands (3 million sq. km). If you add it up, it turns out that a total of 75% or three quarters of the Earth’s surface is under water.
However, in order to answer the question of how much water there is on Earth, it is not enough to determine the area of water on the globe (although people managed to finally do this only in the 20th century). To determine the total volume of the hydrosphere of our planet, it is necessary to know the depths of all reservoirs, the thickness of glaciers and the amount of groundwater.
Today it is believed that the volume of the earth's hydrosphere is approximately 1500 million cubic meters. Of these, 1370 million cubic meters. water accounts for the ocean's share, 28 million cubic meters. – on glaciers, approximately 100 million cubic meters. water is located underground, and the remaining volume of water is contained in lakes and rivers.
What percentage of fresh water is on Earth
The amount of fresh water in the total volume of the earth's hydrosphere is small - only 32.1 million cubic km. or 2% of the Earth's water reserves. However, of these two percent, 80% is in a frozen state, in hard-to-reach glaciers in the highlands and poles of the globe.
The Earth's hydrosphere can be divided into two categories - salty and fresh water. The most valuable and vulnerable part of the hydrosphere is fresh water, which, along with the atmosphere and food, is the most important source of maintaining human life.
Fresh water for human needs comes mainly from rivers and reservoirs formed by natural flow, lakes, reservoirs, as well as from underground (ground) reserves. Fresh water resources on Earth in general are not very large. Of the total water reserves on the globe, 95-98% is salt water of the seas and oceans. The remaining 2-5% is fresh water, but most (about 80%) of it is concentrated in the ice of the Antarctic and Arctic, as well as in mountain glaciers.
With the development of production, population growth and an increase in the level of cultural and public services, fresh water consumption throughout the world has increased significantly and continues to increase. What yesterday seemed like an inexhaustible gift of nature is now becoming a matter of saving, as the shortage of fresh water is rapidly increasing.
The production of 1 ton of coal requires an average of 6 tons of water; 1 t of ore concentrate - 30 t, 1 t of cotton - 200 t; 1 t of synthetic fiber - 250 t, 1 t of rubber - 2500 t, 1 t of copper - 5000 t.
There is no more or less accurate accounting of fresh water consumption in the world. Nevertheless, there is reason to believe that the entire population of the globe consumes approximately 7 billion tons per day, or 2500 km 3 per year. Note that the figure for daily water consumption is comparable to the volume of all minerals mined in the world per year.
Since fresh water resources are distributed unevenly in the world, many countries have been experiencing an acute shortage for a long time. There are almost no own sources of fresh water in the countries of the Arabian Peninsula, where sea desalinated water is used. In the Persian Gulf region, 48 desalination plants are operating and are being designed. Desalinated water is used residents of Gibraltar, the Bahamas, Bermuda, Curaçao, etc. Hong Kong (Hong Kong) and Singapore import water from Malaysia. Fresh water resources are insufficient in Japan, Italy, Algeria, Tunisia, Ethiopia, Pakistan, Afghanistan and many other countries.
The Soviet Union has huge reserves of fresh water. Approximately 800 thousand rivers of our country provide a total flow of an average of more than 4,700 km 3 of water, of which almost 22% is groundwater. Lake Baikal is a unique reservoir, where 1/5 of the world's fresh water is concentrated. However, it should be taken into account that more than 80% of the flow occurs in economically underdeveloped areas. Approximately 60% of the runoff occurs during the period of floods and floods. In the European part of the USSR, where the bulk of the population and industry are concentrated, as well as vast areas of irrigated agriculture (in the southern regions), there is only 14% of the country's river water flow. If in the whole country water consumption averages 6% of renewable resources, then in a number of regions with highly developed industry and irrigated agriculture it reaches 40% or more.
In 1983, the total consumption of fresh water in the USSR amounted to 279 km 3, of which 37% went for production needs (excluding agricultural needs), 8% for drinking water needs, the rest of the water was used in agricultural production.
Much is currently being done to provide water. Water pipelines stretch for hundreds of kilometers in Siberia. Water was brought to Krasnovodsk - on the shore of the Caspian Sea - by tankers from Baku, and is now extracted through desalination.
Dnieper water flows through the 400 km long North Crimean Canal to Kerch. Water from the Amu Darya canal is supplied by pumping stations to the arid and waterless steppes. The Kara-Kum canal, over 100 km long, made it possible to transform 450 thousand hectares of desert lands in Turkmenistan into cotton fields. In the Central Asian republics, due to lack of water, more than 28 million hectares of semi-desert and desert lands are mainly used as unproductive pastures. If we give them irrigation, then each cubic kilometer of water in Uzbekistan would ensure the production of agricultural products worth 0.5 billion rubles per year. However, this problem is complex and requires further study.
Water supply has become one of the determining factors in the development of the national economy in Donbass. Through a canal system, Donbass is supplied with water from the Dnieper and Seversky Donets rivers. 4.5 thousand km of main water pipelines, over 500 water intake wells, about 200 filtering and pumping stations, and more than 20 reservoirs were built.
More than 2 billion m3 of water are transferred annually to the territory of the Donetsk and Krivoy Rog basins. Part of it goes to irrigation, part to industry, more than half (drinking water) goes to the population and for the economic needs of enterprises. To make up for the lack of water in many areas, geologists are searching for new groundwater resources. Research is being conducted into the feasibility of transferring water from northern rivers.
In the USA, Canada, Great Britain and a number of other countries, the issue of towing icebergs from the northern regions of the Pacific Ocean and the Atlantic to obtain fresh water is being discussed. In the North Atlantic, approximately 7,500 icebergs are formed annually, with a large iceberg containing up to 150 million tons of water. In one of the projects it was proposed to tow icebergs to the Los Angeles area and melt them there under the sun, after covering them with coal dust. French experts have proposed a project to tow medium-sized icebergs from Antarctica to the Persian Gulf or Red Sea for use in Saudi Arabia. However, many problems remain unresolved, and the economics of such an undertaking are still unclear, although some believe that this method of “producing” fresh water will be cheaper than desalination of sea water.
Water is life. And if a person can survive for some time without food, it is almost impossible to do this without water. Since the heyday of mechanical engineering and the manufacturing industry, water began to become polluted too quickly and without much attention from humans. It was then that the first calls appeared about the importance of preserving water resources. And if, in general, there is enough water, then the reserves of fresh water on Earth constitute a negligible fraction of this volume. Let's look into this issue together.
Water: how much is there and in what form does it exist?
Water is an important part of our life. And it is this that makes up most of our planet. Humanity uses this extremely important resource every day: for domestic needs, production needs, agricultural work and much more.
We are used to thinking that water has one state, but in fact it has three forms:
- liquid;
- gas/steam;
- solid state (ice);
In a liquid state, it is found in all water basins on the surface of the Earth (rivers, lakes, seas, oceans) and in the depths of the soil (groundwater). In its solid state we see it in snow and ice. In gaseous form, it appears in the form of clouds of steam.
For these reasons, calculating the amount of fresh water on Earth is problematic. But according to preliminary data, the total volume of water is about 1.386 billion cubic kilometers. Moreover, 97.5% is salt water (undrinkable) and only 2.5% is fresh.
Fresh water reserves on Earth
The largest accumulation of fresh water is concentrated in the glaciers and snows of the Arctic and Antarctica (68.7%). Next comes groundwater (29.9%) and only an incredibly small part (0.26%) is concentrated in rivers and lakes. It is from there that humanity draws the water resources necessary for life.
The global water cycle changes regularly, and this causes the numbers to change as well. But in general, the picture looks exactly like this. The main reserves of fresh water on Earth are in glaciers, snow and groundwater; extracting it from these sources is very problematic. Perhaps, not in the distant future, humanity will have to turn its attention to these sources of fresh water.
Where is the most fresh water?
Let's take a closer look at the sources of fresh water and find out which part of the planet has the most of it:
- Snow and ice at the North Pole make up 1/10 of the total fresh water reserve.
- Today, groundwater also serves as one of the main sources of water production.
- Freshwater lakes and rivers are typically located at high elevations. This water basin contains the main reserves of fresh water on Earth. Canadian lakes contain 50% of the world's total freshwater lakes.
- River systems cover about 45% of our planet's land area. Their number is 263 units of water basin suitable for drinking.
From the above, it becomes obvious that the distribution of fresh water reserves is uneven. Somewhere there is more of it, and somewhere it is negligible. There is one more corner of the planet (except Canada) where the largest reserves of fresh water on Earth are. These are Latin American countries, where 1/3 of the world's total volume is located.
The largest freshwater lake is Baikal. It is located in our country and is protected by the state, listed in the Red Book.
Shortage of usable water
If we go from the opposite direction, then the continent that most needs life-giving moisture is Africa. There are many countries concentrated here, and they all have the same problem with water resources. In some areas there is extremely little of it, and in others it simply does not exist. Where the rivers flow, the water quality leaves much to be desired, it is at a very low level.
For these reasons, over half a million people do not receive water of the required quality, and, as a result, suffer from many infectious diseases. According to statistics, 80% of disease cases are associated with the quality of fluid consumed.
Sources of water pollution
Water conservation measures are a strategically important component of our lives. Fresh water is not an inexhaustible resource. And, moreover, its value is small relative to the total volume of all waters. Let's look at the sources of pollution so we know how we can reduce or minimize these factors:
- Wastewater. Numerous rivers and lakes were destroyed by wastewater from various industrial productions, from houses and apartments (household slag), from agricultural complexes and much more.
- Disposal of household waste and equipment in the seas and oceans. This type of burial of rockets and other space devices that have served their useful life is very often practiced. It is worth considering that living organisms live in reservoirs, and this greatly affects their health and water quality.
- Industry ranks first among the causes of water pollution and the entire ecosystem as a whole.
- Radioactive substances, spreading through water bodies, infect flora and fauna, making the water unsuitable for drinking, as well as for the life of organisms.
- Leakage of oil-containing products. Over time, metal containers in which oil is stored or transported are subject to corrosion, and water pollution is a result of this. Atmospheric precipitation containing acids can affect the condition of the reservoir.
There are many more sources, the most common of them are described here. In order for the fresh water reserves on Earth to remain suitable for consumption for as long as possible, they need to be taken care of now.
Water reserve in the bowels of the planet
We have already found out that the largest reserve of drinking water is in glaciers, snow and soil of our planet. In the depths of fresh water reserves on Earth are 1.3 billion cubic kilometers. But, in addition to the difficulties in obtaining it, we are faced with problems associated with its chemical properties. The water is not always fresh; sometimes its salinity reaches 250 grams per 1 liter. Most often there are waters with a predominance of chlorine and sodium in their composition, less often - with sodium and calcium or sodium and magnesium. Fresh groundwater is located closer to the surface, and salt water is most often found at a depth of up to 2 kilometers.
How do we spend this most valuable resource?
Almost 70% of our water is wasted to support the agricultural industry. In each region this value fluctuates in different ranges. We spend about 22% on all global production. And only 8% of the remainder goes to household consumption.
More than 80 countries are facing a decline in drinking water reserves. It has a significant impact not only on social but also economic well-being. It is necessary to look for a solution to this issue now. Thus, reduced consumption of drinking water is not a solution, but only aggravates the problem. Every year, the supply of fresh water decreases to 0.3%, and not all sources of fresh water are available to us.
