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PROTECTION OF WATER. The water and the air are the most important elements in physical and chemical processes on the surface of the earth
The water and the air are the most important elements in physical and chemical processes on the surface of the earth. Academician Karpinsky called water the most precious natural resource. Unlike mineral deposits, water resources are renewed in the course of exploitation itself. This is due to its constant circulation in the ocean-atmosphere-earth-ocean system. No matter how much water is consumed in daily industrial life, its amount does not decrease. With time and under certain conditions water regains its properties and its fitness for drinking. This is probably the reason why water resources for a long time appeared to be unlimited. However, this view has substantially changed in the past 30 or 40 years as water became a factor which dictates prospects for economic development. In the economy water is a raw material like any other.
Resources of river, lake and underground fresh waters are distributed very unevenly on the continents. Shortage of water in different areas of the world is due not only to uneven distribution of water resources but also to its more varied and intensive use. Scarcely any type of product is manufactured without water taking part in the process in one form or another. It should be added that scope of water resource exploitation is growing rapidly due to population growth, fast development of industry and expansion of irrigated land area.
It is obvious that the exploitation of water resources is extremely varied at the present time. An enormous amount of water is used in industry. To manufacture one ton of paper 100 m3 of water is required, one ton of synthetic fibres — from 2,500 to 5,000 m3 of water. The obtaining of a ton of woolen fabric requires the use of 200 cubic meters of clean fresh water, that of a ton of capron - 5,600 cubic meters.
It has been estimated that industry consumes about 85 per cent of the water in cities. This leaves about 15 per cent for the daily needs of the people.
A sharp increase in water consumption on the planet may lead to a water shortage in the nearest future. In view of this, measures are being worked out to increase water resources and exploit them more rationally.
There are two ways to redistribute river water by means of reservoirs and through canals.
Last century cascades of hydroelectric power plants have been built with reservoirs, the largest ones are on the Volga, Kama, Dnieper, Angara, and Yenisel.
Reservoirs are an example of how man intervenes to a considerable extent in natural processes over large areas. Reservoirs help to solve energy problems, irrigate agricultural land, improve water transport, supply large enterprises, cities and other populated areas with water. They form the basis both for fisheries and recreation and tourist zones. Nevertheless, there is a great disadvantage of man-made seas as they completely destroy the original environment over there.
Canals are important not only for redistributing water but also as transport routes. As such they are artificial rivers built by mighty excavating machines.
Supplies of underground waters arc considerable and therefore, their rational use helps to compensate for moisture shortages. Geothermal (hot) waters are a kind of ground water source. Water being obtained from the earth’s interior by deep drilling. These hot waters are used to generate electricity (geothermal electric plants), heat homes aid livestock breeding farms and also in hot- houses. Recently, geothermal waters have been used for breeding fish in ponds in Siberia.
6. Answer the questions to the text:
1. How could people compensate shortage of water in some areas?
2. What are the consequences of sharp increasing of water consumption?
3. What problems do people solve with the help of reservoirs?
4. Do reservoirs play positive role in economy as well as in ecology?
5. What way can underground waters be applied?
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