Friday, January 30, 2009


Where Is The Water?

Cartographer: UNEP/GRID-Arendal

Fresh water is gold. It is pivotal for humans; without it we simply die. But it is also an important factor in understanding the water cycle and hence climate changes. The big unknown is groundwater. How much and where do we find the groundwater?

UNEP/GRID-Arendal have started to gather more systematic data on the subject. For climate change studies we need the help of space geodetic techniques together with traditional in-situ measurements.

- Groundwater represents over 90% of the world's readily available freshwater resource (Boswinkel, 2000). About 1.5 billion people depend upon groundwater for their drinking water supply (WRI, UNEP, UNDP, World Bank, 1998).

- The amount of groundwater withdrawn annually is roughly estimated at 600-700 km3, representing about 20% of global water withdrawals (WMO, 1997).

- A comprehensive picture of the quantity of groundwater withdrawn and consumed annually around the world does not exist.

Geodesists are teaming up with other scientists to reveal more useful information in a big international project called IGCP 565.

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