Monday, August 5, 2013

Water Usage Around the World

Mapping global data provides a way to understand differences among countries in order to evaluate development needs as well as conservation priorities.  The map below highlights some interesting variability about water withdrawals per capita.  As you can see, North America, Australia, New Zealand stand out as high consumers as do areas of central and western Asia.  


But these numbers do not tell everything we need to know.  Around the world, about 70% of all water usage goes toward agriculture--mainly irrigation and food processing.  Only 20% goes toward industrial uses and a scant 10% goes toward household use.  

These numbers vary from country to country, but the above map in some ways highlights countries that utilize tremendous amounts of water for agricultural purposes.

If we drill down into household use, the variations are staggering.  In the U.S., we utilize roughly 320 gallons of water per day for household use, with approximately 1/3 of this precious resource used for lawn irrigation.  In contrast, Yemen uses about 16 gallons of water per day for household use.

And Yemen is running out of water.  In the capital city of Sana'a, where water is extracted from groundwater, the aquifer is dropping meters per year.  They are in a highly unsustainable situation for long-term water usage.

Many have suggested that the next major global conflicts will not be over oil, but over water.  I don't know if this is true or not, but there are many areas of the world that are in very difficult situations.

In our own country, we have regions that are in trouble.  Perhaps the most dire situation is in the Great Plains where over 2 million people rely on the Ogallala Aquifer for drinking water.  Right now, over pumping is causing significant drops in this aquifer and it is expected to last just about 25 more years using current withdrawals.  The region receives 12-24 inches of rain a year and they are taking out far more water than is being returned to the aquifer.  Indeed, the aquifer houses water that fell on our planet hundreds of thousands of years ago.  It will all be gone in a generation.

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