Water is vital for all known forms of life. Covering 71% of the Earth's surface, it is found mostly in oceans and other large water bodies. 1.6% of the total mass of the Earth's water is below ground in aquifers and 0.001% is in the air as vapor, clouds, and precipitation (rain, snow and sleet).

The Earth's water moves constantly through a cycle of evaporation and transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Over land, evaporation and transpiration contribute to the precipitation over land - thus deforestation and other changes to land can have wide and long-lasting effects through their impact on the water cycle.

Some observers estimate that by 2025 more than half of the world population will be vulnerable to a lack of water. Appropriate water supply and water purification technologies can help.

External links[edit | edit source]

Subcategories

This category has the following 24 subcategories, out of 24 total.

B

C

G

H

M

S

V

W

Pages in category "Water"

The following 200 pages are in this category, out of 217 total.

(previous page) (next page)
(previous page) (next page)

Media in category "Water"

The following 3 files are in this category, out of 3 total.