‘Fog harvesting’ can produce water for drinking and agriculture in dry areas of the world

With less than 1 mm annual rainfall per year, Chile’s Atakama Desert is one of the most dried places in the world. The main water sources of the cities of the region are layers of underground rocks with water -filled holes spaces that were recharged in the last 17,000 to 10,000 years ago.

Now, local researchers have evaluated whether “fog harvesting”, a method where fog water is collected and saved, is a possible way to provide the inhabitants of informal settlements with very essential water.

University of University and Assistant Professor of First Co.-First Co. Virginia Carter Gambarini said, “This research represents a remarkable change in the perception of fog water use-from a villager, but a small scale solution to a practical water resources for cities.” author of Limitations in environmental science Study.

“Our findings suggest that fog can serve as a supplement of urban water in the drawlands where climate change increases water scarcity.”

Catch moisture

Fog collectors typically have a trap suspended between two positions. The mesh serves as a interception surface to catch moisture. The drops collide on the mesh and fall into a gutter that goes to the water storage tank. This is an inactive system that requires no external energy.

Researchers studied a one-year area at Alto Hostilo, a rapidly growing municipality located in the Hyper-Dry Atakama Desert. Due to the rapid development of the city, around 10,000 people live in informal settlements. Of these settlements, only 1.6% of the water distribution is connected to the network and most of the residents get water through trucks.

Carter said, “The collection and use of water, especially from non-traditional sources such as fog water, represents an important opportunity to improve the quality of life of the residents,” Carter said.

Researchers found that in an area of ​​100 square kilometers around Alto Hostilo, 0.2 and 5 liters of fog can be harvested each day between fog water. This capacity, however, is limited to the height of high lies outside the city boundaries.

During the peak season of the study, in August and September, the collection capacity reached 10 liters per square meter and day.

By demonstrating its ability to Alto Hosio, one of Chile’s most stigma yet, one of the rapid urbanization cities, the study makes the basis for widespread adoption in other water-watery urban areas, “Universe Liberey Day Braxelace and First A CO researcher said the right to the article.

However, fog harvesting should not be seen as the only solution of water scarcity, but as part of a broad urban water management strategy, researchers said.

Reduce water scarcity in urban areas

Collected water can be used for drinking, irrigation of green places and local food production. However, large storage systems, piping infrastructure, and methods of delivery would be necessary, researchers said.

Depending on the annual average water collection rate of 2.5 liters per square meter per day, researchers said that 17,000 square meters can produce enough water to meet the demand for weekly water (300,000 liters) for urban slums, And 110 square meters can be found annual demand for irrigation of the city’s green space (100,000 liters). Similarly, fog water can be used for soil -free agriculture, with a yield of 15 to 20 kg of leafy green vegetables a month.

To work in other places, geographical and atmospheric conditions must be correct.

“Major prejudices include fog density, appropriate wind pattern, and well -oriented high landforms. Also, because the fog is seasonal in many areas, this variability should be considered,” Verbrughe said.

Future research will also need to evaluate the viability of fog harvesting in large settlements.

“We expect to encourage policy makers to integrate this renewable source in national water strategies,” Carter said. “It can increase climate change and urban flexibility for rapid urbanization by improving access to clean water.”