Fresh water - the opposite of seawater , covers that part of the available water of the Earth in which salts are contained in minimal quantities.
Water whose salinity does not exceed 0.1 ‰, even in the form of steam or ice, is called fresh. Massifs of ice (for example, icebergs) in the polar regions and glaciers contain the largest part of the Earth’s fresh water. In addition, fresh water exists in rivers, streams , groundwaters, fresh lakes , as well as in the clouds. According to various estimates, the share of fresh water in the total amount of water on Earth is 2.5-3%.
About 85–90% of the fresh water reserves are in the form of ice .
In connection with the expanding pollution of water sources, population growth, and the development of new territories, the task of artificially producing fresh water arises. This is achieved:
- desalination of sea water, including solar desalination ;
- condensation of water vapor from the air using deep sea water;
- condensation of water vapor in daily accumulators of cold, in particular of natural origin, such as caves in coastal cliffs .
The latter method creates huge natural reserves of fresh water in the coastal areas of several countries that have been discovered recently. Formations with fresh water sometimes go under the seabed , and through the cracks in impermeable layers fresh keys are beaten.
The cost of fresh water becomes so high that the production of refrigeration units that receive water from moist air by condensation has begun.
Content
- 1 Freshwater Reserves
- 2 Usage Prospects
- 3 See also
- 4 notes
- 5 Links
Fresh Water Reserves
| View | Volume, km³ | % [1] |
| Glaciers, icebergs, constant snow | 24,000,000 | 68.7 |
| Underground fresh water | 10 500 000 | 30.1 |
| Eternal Frost | 300,000 | 0.86 |
| Fresh Lakes | 91,000 | 0.26 |
| Atmospheric vapors | 12 900 | 0.04 |
| Rivers | 2120 | 0.006 |
| Total | 35,000,000 | one hundred |
The distribution of fresh water around the globe is extremely uneven. In Europe and Asia , where 70% of the world's population lives, only 39% of river waters are concentrated.
In terms of surface water resources, Russia holds a leading position in the world. About 20% of the world's reserves of lake fresh water and more than 80% of Russia's reserves are concentrated in the unique Lake Baikal alone. With a total volume of 23.6 thousand km³ in the lake, about 60 km³ of natural waters of rare purity are reproduced annually.
Prospects for use
According to the UN, at the beginning of the 2000s, more than 1.2 billion people live in conditions of constant shortage of fresh water, about 2 billion suffer from it regularly. By the middle of the XXI century, the number of people living with constant water shortages will exceed 4 billion people [2] . In such a situation, some experts say that the main advantage of Russia in the long term is water resources, and the production of water-intensive products may become the dominant direction in the development of the Russian economy [3] .
See also
- Distilled water
- Freshwater pollution
- Drinking water
- Freshwater
- Agua Dulce
Notes
- ↑ The World's Water . water.usgs.gov . Date of treatment January 14, 2019. // USGS (eng.)
- ↑ Water for people, water for life. UN World Water Resources Report . unesdoc.unesco.org . Date of treatment January 14, 2019 . - M., 2003.
- ↑ Danilov-Danilyan V.I. The global problem of fresh water shortage . www.socionauki.ru . Date of treatment January 14, 2019. // Century of globalization. - 2008. - No. 1. - P. 45-56.
Links
- V. Mosin. Fresh water . www.o8ode.ru . Date of treatment January 14, 2019.