Capturing water from fog - on a large scale - could provide some of the driest cities in the world with drinking water. This is what researchers in Chile have concluded after studying the potential of fog harvesting in the desert city of Alto Hospicio in the north of the country.

Fog harvesting is a relatively simple process. Mesh panels are hung between poles, and as moisture-laden clouds pass through the mesh, water droplets form and are channelled into pipes and storage tan

As cities grow, so does their demand for water, often surpassing the capacity of traditional sources. Many fast-expanding urban areas in dry regions struggle to supply their residents with enough clean water.

With less annual rainfall than 1 mm per year, Chile's Atacama Desert is one of the driest places in the world. The main water source of cities in the region are underground rock layers that contain water-filled pore spaces which last recharged between 17,