Fog harvesting could combat water scarcity in dry areas

Harvesting fog could ease water scarcity in the world's driest place, a new study has suggested.

In Chile's Atacama Desert, with annual rainfall of less than 1mm per year, the main water source is underground water-filled spaces which last recharged between 17,000 and 10,000 years ago.

So-called fog harvesting, where fog water is collected and saved, is a feasible way to provide much needed water, scientists said in a research published in Frontiers in Environmental Science.

In a year-long field study, scientists found it was possible to collect as much as five litres of water per square metre each day.

Virginia Carter Gamberini, a co-author of the study, said the research showed it was possible to scale up fog water use, "from a rural, rather small-scale solution to a practical water resource for cities."

"Our findings demonstrate that fog can serve as a complementary urban water supply in drylands where climate change exacerbates water shortages," she said.

"The collection and use of water, especially from non-conventional sources such as fog water, represents a key opportunity to improve the quality of life of inhabitants."

Fog collectors typically consist of a mesh suspended between two posts. Water droplets collect on the mesh and fall into a gutter leading to water storage tanks.

Collected water could be used for drinking, irrigation, and local food production. However, researchers said large storage systems, piping infrastructure, and ways of distribution would still be required.