rational use of water resources is one of the most important environmental problems.The intensive development of agriculture, manufacturing industry, the economy in general, urban growth is possible while maintaining and increasing stocks.In the first place today among the expenditures of mankind on nature protection are the costs to preserve the quality of fresh water.The total value of its reserves are many times higher than the cost of any other type of raw material used.
in the successful transformation of nature are important qualitative water resources.Also important is the number of them.As a rule, any project for the transformation of nature is largely related to the impact on water resources in one degree or another.
With the rapid development of the world economy rapidly increasing consumption of "gidrozapasov."The consumption of every eight to ten years doubles.Along with this increased the level of contamination.Thus, water resources are gradually depleted.
total volume of the hydrosphere is large enough.A small portion of this volume (about two per cent) is fresh water.They directly benefit people.
importantly, usable in one or other economic sectors of the economy are the lake, river, sea sources.It is of great importance, and underground and atmospheric moisture, ice and polar highlands regions.Thus, almost all the components of the hydrosphere (except water minerals and biomass) are considered sources "gidrosyrya".However, the greatest value to people are fresh water (lake, river, groundwater).They are used in agricultural and industrial, and domestic sphere.Rivers, lakes and groundwater sources are considered most readily available, can be easily controlled.Furthermore, in the cycle they are updated continuously.
People do not use fresh water contained in glaciers.Today, a person uses less than one percent of the total volume of the hydrosphere.According to experts, there is a threat not only to regional but also a global shortage of water to meet economic and social needs.
obvious that you can make up for the water resources, attracting large numbers of all parts of the hydrosphere.In this field, successfully conducted an active work.For example, in some states carry out the desalination of sea water, to develop methods of influence on the water contained in the atmosphere.In addition, underground reserves are often involved.At the same time, plans for use of water, canned in glaciers.
should be noted that the most valuable part of the "gidrosyrya" unevenly distributed across continents.Most secured underground resources and river runoff is considered the equatorial belt.Particularly rich are located near this area of Africa and South America.In these areas account for twenty-five to fifty thousand cubic meters of the total of the river and the order of ten to twenty-five thousand cubic meters of groundwater runoff per person per year.National Water Resources of subtropical, temperate south, and tropical Eurasia have a volume ten times smaller.Poor maintenance is the territory of Arabia, Afghanistan, Sahara, south of Central Asia.The northern half of the subtropical and temperate zone is characterized by an average availability of water resources.Here, the amount of the total flow greater than twenty-five thousand cubic meters per person per year.In the north-east of Russia, as well as the northern territories of Canada's water supply more than one hundred thousand cubic meters of the total runoff per person per year.On special place is Australia.Despite the fact that in general, on the continent of water is sufficiently small, its average water supply performance is higher than the global average value.
