Scientific correspondent, BBC News
Taking fog water – to a large extent – it could provide some of the smallest cities in the world with drinking water.
The researchers in Chile concluded this after studying the potential of fog harvesting in the desert city of Alto Hospicio in the north of the country.
The average rain in the region are less than 0.19 inches (5 mm) per year.
“The city also has a lot of social problems,” said leading researcher Dr. Virginia Carter Gamberini of Universidad Mayor. “Poverty, drugs, many slams.”
Without access to water supply networks, people in straw rely on the drinking water delivered by the truck.
However, the clouds of fogs that regularly gather through Mountain City are an unused source, the researchers say.
How do the fog harvest?
The capture of fog water is extremely simple – the net is hung between the columns, and when the clouds filled with moisture pass through that fine mesh, drops of shape. The water is then directed in the pipes and tanks.
It has been used in a small volume for several decades, mostly in rural south and Central America – in places with real foggy conditions. One of the largest water collection systems for fog is in Morocco, on the edge of the Sahara desert.
However, Dr. Carter says that the “new era” of a much larger fog harvest could provide a safer and sustainable supply of water in urban environments in which it is most needed.
She and her colleagues conducted estimates of how much water can produce fog harvesting and combined this information with studies of cloud formation in satellite images with time forecasts.
From this, they concluded that the clouds that regularly form through the Pacific Ocean – and blows around the coastal mountain city – can provide people with alto Hospicio – these slums a sustainable source of drinking water. Have published their discoveries in Work in the journal Borders of Environmental Sciences.
The fog of alto Hospicio is formed through the Pacific Ocean – when warm, humid air flows over cold water – and then blows over the mountains. Here, a reliably foggy conditions were made possible by Dr. Carter and her colleagues to specify areas where the largest volume of water can be used to be harvested regularly from the clouds.
Based on the annual average water collection rate of 2.5 liters per square meter of the net per day, researchers worked:
- 17,000 square meters of mesh could produce enough water to satisfy the weekly demand of water of 300,000 liters that the truck currently ships to urban slams
- 110 MQ M could meet the annual reimbursement of city green spaces
- Fog water could be used for soil without soil (hydropon), with yields from 33 to 44 lb (15 to 20 kg) green vegetables per month
Alto Hospicio is on the edge of the Ataca desert – one of the smallest places on Earth. With little and no rainfall, the main source of water in the region are underground aquifers – layers of rocks containing spaces filled with water – which were last filled thousands of years ago.
Because the urban population grows and sought to supply water from mining and industry, scientists say there is an urgent need for other sustainable sources of pure water.
Dr. Gamberini explained that Chile is “very special” for our sea fog “because we have an ocean along the whole country and we have mountains.”
Her team is currently working on the “fog fog fog folders” of the whole country.
“Cloud water,” as Dr. Carter describes it, she could, she said, “improve the resistance of our cities to climate change, improveing access to clean water.”
