Water resources of the world

Rational use of water resources is considered one of the most important environmental tasks. Intensive development of the agricultural, manufacturing sector, the economy as a whole, the growth of cities are possible provided that the reserves are preserved and increased. In the first place today, among expenditures of mankind on the protection of nature are costs aimed at preserving the quality of fresh water. The total cost of its reserves is many times higher than the cost of any other type of raw materials used.

In the process of successful transformation of nature, high-quality water resources are of great importance. Their number is also important. As a rule, any project on the transformation of nature is largely related to the impact on water resources to one degree or another.

Against the backdrop of the rapid development of the world economy, the consumption of "hydraulic reserves" is intensively increasing. At the same time, the expenditure is doubled every eight to ten years. Along with this, the level of pollution also increases. Thus, water resources are gradually depleted.

The total volume of the hydrosphere is quite large. A small part of this volume (about two percent) is made up of fresh water. They are directly used by man.

The most important, suitable for use in this or that economic branch of the economy are lake, river, sea sources. Of great importance is the underground and atmospheric moisture, the ice of the polar and highland regions. Thus, practically all the components of the hydrosphere (with the exception of the moisture of minerals and biomass) are considered to be sources of "hydrospray". However, fresh water (lake, river, underground) is of the greatest value for people. They are used in the agricultural, industrial, and household spheres. River, lake and underground sources are considered the most accessible, easily adjustable. In addition, in the process of cycling, they are continuously updated.

People do not use fresh water contained in glaciers. Today, less than one percent of the total hydrosphere volume is used by humans. According to experts, there is a threat not only of regional but also global lack of water to meet economic and domestic needs.

It is obvious that water can be replenished by attracting large masses of all parts of the hydrosphere. In this area, active work is quite successful. So, in some countries desalination of sea waters is carried out, methods of influence on water contained in the atmosphere are being developed. In addition, underground reserves are more often involved. Along with this, plans are being developed for the use of water conserved in glaciers.

It should be noted that the most valuable part of the "raw material" is distributed unevenly across the continents. The equatorial belt is considered the most provided resource of underground and river flow . In particular, the parts of Africa and South America located near this zone are rich. These territories account for between twenty-five and fifty thousand cubic meters of full river and about ten to twenty-five thousand cubic meters of underground flow per person per year. The national water resources of the countries of the subtropical, southern temperate, and also the tropical belt of Eurasia have a volume ten times smaller. Weakly provided are the territories of Arabia, Afghanistan, the Sahara, the south of Central Asia. The northern half of the subtropical and temperate zones are characterized by an average water supply. Here, the total runoff exceeds twenty-five thousand cubic meters per person per year. In the north-east of Russia, as well as in the northern territories of Canada, water supply is more than one hundred thousand cubic meters of total flow per person per year. In a special place is Australia. Despite the fact that on the whole the continent has little water, its average water availability is higher than the world average.