The rational use of water resources is considered one of the most important environmental problems. Intensive development of the agricultural, manufacturing sector, the economy as a whole, urban growth are possible provided that reserves are maintained and increased. In the first place today among the costs of humanity to protect nature are costs aimed at maintaining the quality of fresh water. The total value of its reserves is many times higher than the value of any other type of raw material used.
In the process of successful transformation of nature, high-quality water resources are of great importance. Important is their number. As a rule, any project on the transformation of nature is largely associated with 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 rapidly increasing. Moreover, the flow rate doubles every eight to ten years. Along with this, the level of pollution 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 fresh water. They are directly used by man.
The most important, suitable for use in one or another economic sector of the economy are lake, river, and marine sources. Of great importance is the underground and atmospheric moisture, ice of the polar and alpine regions. Thus, almost all components of the hydrosphere (with the exception of the moisture of minerals and biomass) are considered sources of "hydrosulfur". However, fresh water (lake, river, underground) is of the greatest value to people. They are used in the agricultural, manufacturing, and household sectors. River, lake and underground sources are considered the most accessible, easily regulated. In addition, during the cycle, they are constantly updated.
People do not use fresh water contained in glaciers. Today, less than one percent of the total hydrosphere is used by humans. According to experts, there is a threat of not only regional, but also global water shortages to meet household and household needs.
It is obvious that replenishing water resources is possible by attracting large masses of all parts of the hydrosphere. Active work is being conducted quite successfully in this area. So, in a number of states they carry out desalination of sea waters, methods are developed for influencing the water contained in the atmosphere. In addition, underground reserves are more often attracted. Along with this, plans are being developed for the use of canned water in glaciers.
It should be noted that the most valuable part of the "hydraulic raw materials" is distributed unevenly across the continents. The equatorial belt is considered to be the most endowed with underground and river runoff resources . Particularly rich are parts of Africa and South America located near this zone. These territories account for twenty-five to fifty thousand cubic meters of total river water 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, temperate south, as well as the tropical zone of Eurasia have a volume ten times smaller. The territories of Arabia, Afghanistan, the Sahara, and the south of Central Asia are considered poorly provided. The northern half of the subtropical and temperate zones is characterized by an average supply of water resources. Here, the volume of total flow exceeds twenty-five thousand cubic meters per person per year. In northeastern 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 in general there is not enough water on the continent, its average water availability is higher than the world average.