托福听力

🎧 听力原文

Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about a surprising solution to water scarcity—fog harvesting. In arid coastal regions, like parts of Chile and Peru, fog is a common occurrence, even though rain is rare. Fog harvesting uses large mesh nets, often made of polypropylene, to capture tiny water droplets from the fog. As the wind blows through the net, droplets collect and coalesce, then drip down into a trough that channels water to a storage tank. Now, you might think this only produces a small amount, but a single net can yield hundreds of liters per day. However, the efficiency depends on several factors: the density of the mesh, the wind speed, and the droplet size. Researchers are also experimenting with different materials to increase yield. So, while fog harvesting isn't a complete solution, it can provide a reliable source of clean water for remote communities. It's low-tech, sustainable, and requires minimal maintenance. But there are challenges, such as the need for frequent cleaning and the fact that it only works in specific climates. Still, it's a promising example of how we can work with nature to address environmental problems.