Testing fluoride levels in Indian wells

In the hilly part of Central India, the Alirajpur and Jhabua districts in Madhya Pradesh are known for the high fluoride levels in their underground water. The government has done a great job of drilling and providing handpumps ...

Disrupting key protein alters biological rhythms in water flea

Researchers from North Carolina State University have shown that the E75 protein is a key regulator of some biological rhythms through interactions with nitric oxide. Suppression of E75 results in longer molt cycles and reduced ...

Image: Baja California

This Copernicus Sentinel-1 image takes us just south of the US border, to the region of Baja California in northwest Mexico. Its capital city, Mexicali, is visible top left of the image.

'Demon oil' on the defensive over climate change

At the dawn of an era scientists have dubbed the Anthropocene, driven by human impact on the planet, the energy industry's four-yearly gathering was forced onto the defensive on climate change.

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Water

Water 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.

This text uses material from Wikipedia, licensed under CC BY-SA