Fog Harvesting: Innovative Solution for Water Scarcity in Arid Cities

Researchers in Chile have found that fog harvesting can provide a sustainable water source for the arid city of Alto Hospicio, where annual rainfall is less than 0.19 inches. By using mesh to capture moisture from fog, substantial amounts of water could be produced to meet the needs of the city’s poor communities and green spaces. This innovative method could also support agricultural practices and promote resilience to climate change.

Fog harvesting presents a viable solution for providing drinking water to some of the world’s most arid cities, as demonstrated by researchers in Chile. Their study, focused on Alto Hospicio, reveals that the average annual rainfall is a mere 0.19 inches (5mm). Lead researcher Dr. Virginia Carter Gamberini from Universidad Mayor highlighted the severe social issues in the city, particularly emphasizing the poverty affecting residents’ access to clean water.

In Alto Hospicio, many inhabitants in impoverished areas rely on water delivered by truck, making fog an untapped resource due to the frequent formation of fog clouds over the city. The method of harvesting fog is straightforward and involves hanging mesh between poles; moisture-laden fog droplets condense on the mesh, which is then funneled into storage facilities. This technique has existed at small scales for decades, primarily in rural regions with suitable fog conditions.

Dr. Carter underscored the potential for transitioning to large-scale fog harvesting systems, asserting that this could ensure a sustainable water supply in urban environments. Through assessment of water production capabilities from fog and combining it with satellite data on cloud formations and weather forecasting, researchers identified significant water yield potential from the fog over the Pacific Ocean.

The researchers calculated that 17,000 square meters of mesh could fulfill the weekly water requirements of 300,000 liters currently brought in by truck. Additionally, 110 square meters of mesh could satisfy the annual needs for irrigation in green spaces. The harvested fog water could also support hydroponic agriculture, yielding up to 44 pounds (20 kilograms) of vegetables monthly.

Situated near the Atacama Desert, which is known as one of the driest places globally, Alto Hospicio’s primary water source has been nearly depleted underground aquifers. With an increasing urban population and the growing demand from mining and industrial activities, researchers stress the urgent need for alternative sustainable water sources. Dr. Gamberini pointed out Chile’s unique geographic advantage for fog harvesting due to its extensive coastline and mountainous terrain.

The research team is in the process of developing a comprehensive fog harvesting map for Chile, advocating that “water from the clouds… could enhance our cities’ resilience to climate change, while improving access to clean water.” This innovative approach may revolutionize water accessibility in arid regions.

In summary, fog harvesting offers a promising solution for alleviating water scarcity in dry urban areas like Alto Hospicio, Chile. With simple technology utilizing mesh to capture fog, significant volumes of water can be harvested to meet the needs of both residents and agricultural practices. This method not only addresses social and environmental challenges but may also pave the way for sustainable water management in the face of climate change.

Original Source: www.bbc.com