Water resources are all water of hydrosphere, that is, water in rivers, lakes, canals, reservoirs, seas and oceans, underground water, soil moisture, water of mountain (ice) and polar glaciers, water vapor of atmosphere. The total amount of water is 1390 million km3 and water of the oceans is 1340 million km3 of that. Fresh water forms less than 3%, and just 0.3% of it is commercially available for use (Shiva, 2008).
Water is fundamental for the existence and development of life. A human being for 80% consists of water. Human life support system has remained unchanged for thousands of years and is based on water-using technologies. Over the last 5000 years of civilization, water supplies remained unchanged, while the world population has increased in hundred times, as well as technological requests for its use immeasurably increased.
Fresh water is the most heavily consumed natural resource. Currently, an average daily global consumption of it reached a volume that is equal to the annual mining of all kinds of minerals. The total world consumption of fresh water is 1000 times bigger than the consumption of all types of industrial raw materials.
In average, one person on the planet annually consumes about 13-14 m3 of fresh water. Everyone’s provision with fresh water was reduced by 2.5 times only in the last 50 years. Reduction of water resources is accompanied with an acute problem of pollution of fresh water. Pollution of fresh water is the process of getting a variety of pollutants into water of the rivers, lakes and underground water. It is caused by direct or indirect contact of pollutants with water in the absence of adequate measures to clean up and disposal of hazardous substances (Kerimova, 2011).
Pollution of fresh water is mostly invisible, because pollutants are dissolved in water. But there are exceptions: foaming detergents, as well as oil and raw sewage floating on the surface. There are some natural pollutants. However, the amount of natural pollutants is negligible in comparison with man-made ones. Thousands of chemicals with unpredictable effects, many of which are new compounds, get annually in the water pools. According to the World Health Organization, 80% of diseases in the world are caused by improper quality and unsanitary water. In rural areas, water quality problem is particularly acute because about 90% of all rural people have used polluted water for drinking and bathing.
The main sources of water pollution are:
- Waste industrial water;
- Waste water of domestic utilities;
- Waste water of agriculture;
- Mining and oil fields water;
- Waste of production in the extraction of various minerals;
- Wooden waste in the wood industry;
- Discharges of water and rail transport (Drabent, 1997).
Earth has huge world reserves of water. However, it is mostly salty water of the oceans. Fresh water reserves which people especially need are small and exhaustible. Many places on the planet have lack of it for irrigation, industrial needs, drinking and other household needs.
At the present time in the world more than a quarter of available renewable freshwater resources are annually consumed, excluding the volume of polluted sources – 55%, i.e. more than half of the available renewable fresh water resources are consumed annually. According to the UN estimates, if the current volume of water consumption remains unchanged, using the world’s fresh water only at the expense of population growth could rise to 70% by 2050. If consumption of water increases and the tempo of pollution of its main sources maintains, then the use of an annual supply of fresh water closes to its limit by 2030.
Water access for the world’s population has been steadily reducing in extensive growth of its average annual consumption per capita. Over the past 80 years, the total fresh water use has increased in 10 times, while world population increased only in 2.5 times and by 2050, every person on the planet will account for only a quarter of the amount of fresh water, comparing to that which was in 1950.
As experts state, the demand for water will still grow faster than the population because the current model of consumption of fresh water will remain, and the increase of an average water consumption per capita will continue. The main consumer of fresh water is agricultural food production – crops and livestock. Currently, the average consumption of fresh water is about 630 m3 per person per year, of which 420 m3 are consumed by agriculture for food production (125 m3 – for household needs, 65 m3 – for industrial production) (Cavanagh, 2000).
The general strategy in the sector of water resources as a part of nature in all countries of the world includes: the subordination of the interests of the individual water users to the national interests, the application of environmentally friendly (“green”) technology in production to improve water quality, prevention of polluting and overheating of water; possibility of positive changes in the environment, taking into account alternative water supply and water consumption.
In recent years, the world’s projects have been developed to increase the supply of fresh water in several ways:
- Construction of reservoirs. With the help of reservoirs it is possible to increase the sustainable discharge of fresh water in addition to 20% from current levels (M Popkin, 2010).
- Desalination of sea water. Desalination of salt seawater has the greatest significance for the areas of artificial irrigation.
- Transportation of water. A number of projects on construction of main water lines for inter-regional water transferring, in particular, from Canada to Mexico and the southern U.S. are in the planning stage. There are also projects of glacial freshwater transportation. In this regard, the glaciers of Antarctica are of the greatest interest, as they contain the largest supply of fresh water. The project involves the conversion of the icebergs in an ice crumbs and then its transportation with cargo ships. The high cost of such projects does not permit going further then projects in preliminary stages of their elaboration, mostly “on paper”, although many countries has shown their interest – the U.S., France, Canada, Saudi Arabia, Egypt, Australia and others. In average, these projects are up to 100 times more expensive than desalination.
- Wastewater cleaning. Annual world water consumption is about 4,000 km3, and the volume of waste water is about 2,000 km3. If we assume that all waste water will be purified according to the regulations then in this case at least 8,300 km3 of clean water will require for dilution (20% of the total waste and 60% of the stable one) (Jofre, 2009).
According to the Intergovernmental Panel on Climate Change, changes in rainfall patterns across the planet will take a place in the nearest future: climate contrasts will be strengthened – droughts and floods will become more intensive. It will create more difficulties for a regular supply of fresh water. Nowadays the water problem already gives rise to the inter-state conflicts, which is best known, due to the Near and Middle East – a zone of predominantly desert climate with low rainfall and a declining level of groundwater.
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Drabent, R.; Bryl, K.; Smyk, B.; Ulbrych, K. (1997). Retinyl palmitate in water environment. Journal of Photochemistry and Photobiology B: Biology, 37(3), pp. 254-260.
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Jofre, J. (2009). Is the replication of somatic coliphages in water environments significant? Journal of Applied Microbiology, 106 (4), pp. 1059-1061.
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Shiva, V. (2008). From Water Crisis To Water Culture. Cultural Studies , 22(3), pp. 498-501.