Where to take fresh water?On our blue planet of about 1400 million km 3 waters, but fresh are much less - only 2,5% of all stocks, about 35 million km 3 . The UN connects with a lack of water of nearly 80% of diseases, qualitative, suitable for drink, of developing countries and nearly 3 million death annually.
Mankind, being in great need in water resources, constantly increases their consumption. For the last fifty years we began to use three times more water that is connected with the sharp growth of the population of the planet and expansion of the irrigated farmland. According to forecasts, in 15 years of 47% of the world population will face threat of water deficiency.
Perhaps, the problem of providing mankind with fresh water can be solved, using the huge water stocks under an ocean bottom which are not so long ago found by scientists. According to the publication in the Nature magazine water-supplies of the low salinity hidden on a continental shelf worldwide are estimated at half a million cubic kilometers.
Water which can be used for delivery to the coastal settlements experiencing water hunger is found in Australia, China, North and South America. “The volume of this water resource exceeds the quantity drawn from a hundred times - under the Earth`s surface last century, since 1900, - the leading author of research doctor Vincent Post (Vincent Post) from the Australian “National center for research and studying of underground waters“ told (National Centre for Groundwater Research and Training, NCGRT). - News of these reserves good news as these volumes of water can support some regions within decades“.
Doctor Post says that scientists knew about availability of fresh water under a seabed, but believed that the special conditions developing only in rare instances are necessary for formation of its stocks. However research showed that “the fresh and saltish water-bearing horizons are lower than a seabed actually everyday occurrence“.
Post explains that these reserves were created for the last hundreds of thousands of years when sea level was on average much lower, than today. Water collected underground as well as today, owing to penetration of an atmospheric precipitation. But when about 20000 years ago glaciers began to thaw and global sea level rose, some land areas were hidden under its salty waters.
Water in underground storages in many cases remained fresh, as well as in the majority of underground sources which are used worldwide. Many water-bearing horizons were (and remained still) are protected from sea water by layers of clay and sedimentary breeds.
Doctor Post sees two ways of development of new water resources. It is extraction of water from floating platforms - approximately in such a way as today pump from - under the ocean oil, or drilling of wells on islands and coasts of the continents close to the water-bearing horizons.
Both ways can be very expensive therefore development of sea sources is potentially possible only after a comparative assessment by criteria of cost and influence on environment with other methods of water supply, such as desalting of salty water or construction of reservoirs on the land.