Harvesting Water From Thin Air
Though southern Africa's Namib Desert is lucky to get a half inch of rain a year, STENOCARA, THE NAMIB BEETLE, finds more than enough to drink. When fog rolls in off the Atlantic, it raises its rear to the breeze and waits for water to condense on its hydrophilic (water-attracting) shell. The drops roll down a network of waxy, hydrophobic (water-repelling) troughs straight into the insect's mouth. Engineers are coming up with systems that mimic the beetle's to harvest water from the atmosphere in arid regions.
The WARKA WATER TOWER is named for the fig tree that serves as a gathering place in many rural African communities. A bamboo frame encloses hydrophilic polypropylene mesh, which funnels fog droplets into a cistern at its base. One tower can produce 25 gallons of clean drinking water a day. It has no moving parts, requires no electricity to operate, and can be assembled largely from local materials.
This low-tech structure is the handiwork of Italian designer Arturo Vittori, who helped develop manned spacecraft for the European Space Agency. Designing space habitats, where efficient use of resources is critical, caused him to think freshly about similar challenges on Earth, he says. Vittori is raising funds to bring his water towers to rural Ethiopia next year.
Chile's bone-dry Atacama Desert is attracting an even simpler water-harvesting device. A team from the Massachusetts Institute of Technology employs coated stainless steel grids as FOG CATCHERS. It envisions them clustering like turbines on wind farms, producing water for agriculture.
In the era of climate change, the world's dry places are expected to get even drier. Lack of clean water could render some regions virtually uninhabitable. A new generation of environmental designers are working to avert such a disaster by grabbing water out of thin air. They aren't magicians--they're just adapting methods that desert creatures have used for millions of years
Richard Schiffman is an environmental journalist, a poet, and the author of two biographies who is based in New York City. In the summer, he hangs out with the elk and the bear in a small cabin in the Sangre de Christo mountains of Northern New Mexico.
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