Harnessing atmospheric moisture can provide a practical supplement to alleviate water stress in desert cities, where millions of people face recurring shortages.
Desert cities are often plagued by water scarcity, with millions of people facing the threat of recurring shortages. In regions like Chile’s Atacama Desert, where megadrought and poor water management have exacerbated the issue, innovative solutions are needed to alleviate water stress.
Water scarcity affects over 2 billion people worldwide, with 40% of the global population living in water-stressed areas.
The main causes include climate change, rapid urbanization, and inefficient water management systems.
According to the United Nations, every minute, a person dies from a water-related disease.
To address this issue, organizations are promoting water conservation techniques, such as rainwater harvesting and efficient irrigation methods.
The Potential of Fog Collection
Rural communities in arid regions have long harvested fog as a source of fresh drinking water. Researchers now believe that this method can be scaled up for larger desert cities. A yearlong assessment of fog collection potential near Alto Hospicio, a rapidly expanding city in northern Chile’s Atacama Desert, found that it’s possible to collect up to 5 liters per square meter each day.
Fog harvesting is a technique used to collect water from fog, providing a sustainable source of water for communities in coastal and mountainous regions.
This method involves installing mesh strips or nets that capture fog droplets, which then flow down the surface as runoff.
Fog harvesting systems can collect up to 100 liters per square meter per day, making it an effective solution for areas with limited rainfall.
It is commonly used in countries such as Chile, Peru, and South Africa.
Water Stress in the Atacama Desert
The Atacama Desert is home to over 8 million people who are under water stress due to megadrought and poor water management. The hundreds of thousands of residents living in fast-growing, densely populated cities like Alto Hospicio are especially at risk. Much of the groundwater in the region is siphoned off for mining and agriculture, leaving little for drinking water.
Water stress occurs when an area's water supply is insufficient to meet its demands.
This can be due to drought, over-extraction of groundwater, or poor water management practices.
According to the United Nations, nearly half of the world's population lives in areas with high water stress.
Water scarcity affects 'agriculture, industry, and human consumption' , leading to economic losses and social impacts.
In severe cases, water stress can lead to food insecurity, migration, and conflict.
Fog Collection: A Practical Supplement
In winter and spring, the Atacama Desert receives moisturizing wafts of coastal fog, called ‘camanchaca‘. Low clouds form as humid air masses moving southward from the Amazon meet cool air over the Pacific Ocean. Fog collection is simple: a 1-meter-square mesh sheet is suspended vertically, facing the fog-loaded wind. Water collects on the mesh and drips into a gutter.
A Promising Solution
While the volume of water collected through fog harvesting is nowhere near enough to meet the needs of cities like Alto Hospicio, it may offer a small bloom of hope in the desert. With water pressure rising, researchers say that fog harvesting could provide a practical supplement to stave off water stress in these regions.
- sciencenews.org | Fog collection could alleviate water stress in desert cities
