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World Water Day, The Stream examines the impact.


In want of water: Drought pushes California farmers further underground


Groundwater drilling causes some parts of state to sink
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Another year of drought has California farmers searching for water deeper and deeper underground. For


World Water Day, The Stream examines the impact.

font   video and   redaction    http://stream.aljazeera.com/story/201503221623-0024639

Another year of drought has California farmers searching for water deeper and deeper underground.
For ‪#‎WorldWaterDay‬, The Stream examines the impact - http://ow.ly/KEe0b

Guarani Aquifer






Guarani Aquifer

From Wikipedia, the free encyclopedia




The Guarani Aquifer, located beneath the surface of ArgentinaBrazilParaguay, and Uruguay, is one of the world's largest aquifer systems and is an important source of fresh water.[1] Named after the Guarani people, it covers 1,200,000 square kilometres (460,000 sq mi), with a volume of about 40,000 cubic kilometres (9,600 cu mi), a thickness of between 50 metres (160 ft) and 800 metres (2,600 ft) and a maximum depth of about 1,800 metres (5,900 ft). It is estimated to contain about 37,000 cubic kilometres (8,900 cu mi) of water (arguably the largest single body ofgroundwater in the world, although the overall volume of the constituent parts of the Great Artesian Basin is much larger), with a total recharge rate of about 166 km³/year from precipitation. It is said that this vast underground reservoir could supply fresh drinking water to the world for 200 years. However, at closer inspection, if the world population were to stay at an equilibrium of about 6.96 billion, not even taking into account that babies need less water than grown adults, this figure reaches 1600 years, allowing about 9 liters per day per person. Due to an expected shortage of freshwater on a global scale, which environmentalists suggest will become critical in under 20 years, this important natural resource is rapidly becoming politicized, and the control of the resource becomes ever more controversial.

GEOLOGY OF THE AQUIFER[EDIT]

The Guarani Aquifer consists primarily of sedimented sandstones deposited by fluvial and eolian processes during the Triassic and Jurassic periods (between 200 and 130 million years ago), with over 90% of the total area overlaid with basalt of a low-permeability, deposited during the Cretaceous period, acting as an aquitardand providing a high degree of containment. This greatly reduces the rate of infiltration and subsequent recharge, but also isolates the aquifer from the Vadose zoneand subsequent surface-associated losses due to evaporation and evapotranspiration.
Research and monitoring of the aquifer in order to better manage it as a resource is considered important, as the population growth rate within its area is relatively high — resulting in higher consumption and pollution risks.
The countries over the aquifer are also the original four Mercosur countries.

REFERENCES[EDIT]

  1. Jump up^ from the BBC

EXTERNAL LINKS[EDIT]

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