Water
hideWater is a ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products. Other water is trapped in ice caps, glaciers, aquifers, or in lakes, sometimes providing fresh water for life on land.
Water moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Winds carry water vapor over land at the same rate as runoff into the sea. Over land, evaporation and transpiration contribute to the precipitation over land.
Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. There is a clear correlation between access to safe water and GDP per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70 percent of freshwater is consumed by agriculture.
For more information about Water, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with water
What's in our water?
Nov 05, 2009 |
4.3 / 5 (3) |
0
(PhysOrg.com) -- Although America's supply of drinking water is considered among the world's safest, there is an urgent need to develop more stringent regulations to guide how water is monitored for pollutants, ...
Water-conserving irrigation strategies minimize overwatering, runoff
Nov 05, 2009 |
4.5 / 5 (2) |
0
Conserving water and reducing the environmental impact of runoff are two of the most important issues confronting container nursery operations. Current regulations and laws in five states limit water consumption ...
Mom was right: Why nice guys usually get the girls
Nov 05, 2009 |
4.6 / 5 (9) |
1
(PhysOrg.com) -- Female water striders often reject their most persistent and aggressive suitors and prefer the males who aren't so grabby, according to new research. Water striders are insects commonly seen ...
Metal-Air Battery Could Store 11 Times More Energy than Lithium-Ion
Nov 05, 2009 |
4.3 / 5 (35) |
10
(PhysOrg.com) -- A spinoff company from Arizona State University plans to build a new battery with an energy density 11 times greater than that of lithium-ion batteries for just one-third the cost. With a ...
3 Questions: Sergey Paltsev on the costs of climate-change legislation
Nov 05, 2009 |
1.7 / 5 (3) |
4
Sergey Paltsev, a principal research scientist in MIT’s Joint Program on the Science and Policy of Global Change, was the lead author of a recent report that analyzed the costs of climate legislation currently ...
Successful Flight Through Enceladus Plume (w/ Video)
Space & Earth / Space Exploration
Nov 04, 2009 |
4.7 / 5 (3) |
0
(PhysOrg.com) -- Cassini has started sending data back from its Nov. 2 flyby of Saturn's moon Enceladus.
Toward home-brewed electricity with 'personalized solar energy'
Nov 04, 2009 |
3.4 / 5 (9) |
4
New scientific discoveries are moving society toward the era of "personalized solar energy," in which the focus of electricity production shifts from huge central generating stations to individuals in their ...
Monash study suggests rainwater is safe to drink
Nov 04, 2009 |
4.3 / 5 (3) |
0
A world first study by Monash University researchers into the health of families who drink rainwater has found that it is safe to drink.
Sandia announces completion of mixed waste landfill cover construction
Nov 03, 2009 |
not rated yet |
0
The Environmental Restoration Project at Sandia National Laboratories reports the successful construction of an alternative evapotranspirative cover at the Mixed Waste Landfill (MWL) in September. The 2.6-acre ...
Plague on their house, but bush rats fight back
Nov 03, 2009 |
not rated yet |
0
(PhysOrg.com) -- Sydney's native bush rats were unintended victims of a campaign to exterminate foreign black rats during a plague epidemic in 1900, according to new research by scientists who plan to reintroduce ...
Over 1,000 fish species 'threatened with extinction'
Nov 03, 2009 |
not rated yet |
0
More than 1,000 freshwater fish species are threatened with extinction, reflecting the strain on global water resources, an updated global "Red List" of endangered species showed Tuesday.
SMOS, Proba-2: Two new ESA satellites successfully lofted into orbit (w/ Video)
Space & Earth / Space Exploration
Nov 02, 2009 |
4.7 / 5 (3) |
0
(PhysOrg.com) -- The second satellite in ESA's Earth Explorer series - the Soil Moisture and Ocean Salinity (SMOS) mission - and the second demonstration satellite under ESA's Project for Onboard Autonomy ...
Colorado county copes with methane mystery
Nov 02, 2009 |
4.7 / 5 (3) |
7
(AP) -- Bernice and Jerry Angely like to show visitors the singed T-shirt a friend was wearing when their water well exploded and shot flames 30 feet high.
Lessons from oil industry may help address groundwater crisis
Oct 30, 2009 |
5 / 5 (3) |
0
Although declining streamflows and half-full reservoirs have gotten most of the attention in water conflicts around the United States, some of the worst battles of the next century may be over groundwater, ...
'Blue energy' seems feasible and offers considerable benefits
Oct 30, 2009 |
4.5 / 5 (8) |
0
Generating energy on a large scale by mixing salt and fresh water is both technically possible and practical. The worldwide potential for this clean form of energy - 'blue energy' or 'blue electricity' - is enormous. However, ...
