Water Resources of the World

Water resources are sources of water (both surface and subsurface) that are useful or potentially useful to humans.

Many uses of water include

· agricultural (69% of the water used);

· industrial (21%). Territorial spread of economic activities is very dependent on water resources. Some industries (e.g. electric power production, ferrous and non-ferrous metallurgy, pulp and paper industry, chemical industry) demand much water and therefore are developed in water-rich areas;

· household (6%). Water resources are of crucial importance not only for water-consuming industries but also for city development and population everyday needs satisfaction;

· recreational activities.

Virtually all of these human uses require freshwater (пресная вода). Only 2.5% of water on the Earth is fresh water, and over two thirds of this is frozen in glaciers and polar ice caps.

Total water supply of the planet (its hydrosphere) makes up 1 bln 400 mln cubic kilometers. These reserves include oceans and seas, rivers, lakes, swaps, storage ponds, underground waters, glaciers and snow, soil moisture and evaporation.

Salt waters of the World Ocean make up 96.5% of the planet’s water reserves; salt subsurface waters - about 1%. Fresh water as already mentioned makes up the left 2.5% of the planet’s hydrosphere.

There are 47 000 cubic kilometers of annual renewable freshwater resources ( водные ресурсы рек или ресурсы речного стока). The average per capita indicator is about 8 000 cubic meters a year (Среднемировой показатель обеспеченности речным стоком (показатель стока на душу населения) составляет около 8 тыс. куб. м/год).

On the whole water-consumption is constantly growing. In 2000 it reached 4 780 cubic kilometers. That is approximately 10% of the total fresh water reserves of the planet.

Water demand already exceeds supply in many parts of the world, and many more areas are expected to experience this imbalance in the near future. About 60% of mainland is very short of fresh water. Some places are supplied with water by cars and even planes – e.g. Saudi Arabia, Kuwait. Hong Kong and Singapore get drinking water from the neighboring China and Malaysia.

Half of the planet’s fresh water supply is in Asia and South America. The left half is in North America, Africa, Europe, Australia and Oceania combined.

If one divides the total water supply of a territory by its water consumption, one will get water-supply indicator (водообеспеченность).

Water supply differs greatly from country to country. Australia and Oceania, South America are highly water supplied (per capita). CIS and North America have the average indicator. Europe and Asia are poorly water-supplied (again if we count the indicator per capita).

Russia has considerable water reserves. Water supply in Russia is about 28.5 thousand cubic meters per capita a year and is more than three times above the world average.

The world's ten longest rivers (below are the average measurements):

1. Nile (6,690 km)

2. Amazon (6,452 km)

3. Mississippi-Missouri (6,270 km)

4. Yangtze (Chang Jiang) (6,245 km)

5. Yenisey-Angara (5,550 km)

6. Huang He (Yellow) (5,464 km)

7. Ob-Irtysh (5,410 km)

8. Amur (4,410 km)

9. Congo (4,380 km or 4,670 km). (The source of this river is disputed.)

10. Lena (4,260 km)

Дата добавления: 2014-01-11