TOEFL Listening

🎧 Listening Transcript

Listen to part of a lecture in an environmental science class. The professor is discussing the role of wetlands in flood prevention. Professor: Today we're going to talk about wetlands, which are often called nature's kidneys because they filter pollutants. But they also play a critical role in flood control. When rivers overflow, wetlands act like natural sponges, absorbing excess water and slowly releasing it over time. This reduces the peak flow of floods, which can prevent damage to downstream communities. However, many wetlands have been drained for agriculture or urban development. In the United States, we've lost over half of our original wetlands. This loss has contributed to more severe flooding in some regions, like the Mississippi River basin. Some scientists argue that restoring wetlands is a cost-effective alternative to building concrete levees or dams. For example, a study in the Midwest found that restoring just one acre of wetland could store up to a million gallons of floodwater, saving millions in flood damage. So, while wetlands may seem like simple muddy areas, they provide ecosystem services that are both economically and environmentally valuable.