TOEFLリスニング

🎧 リスニング原文

Listen to part of a lecture in an environmental science class. The professor is discussing the role of wetlands in flood control. "Good morning. Today we're going to talk about wetlands, and specifically their function in mitigating floods. You might think of wetlands as just swampy, unproductive land, but they actually provide critical ecosystem services. One key service is flood control. How does that work? Well, wetlands act like natural sponges. They absorb excess water from heavy rainfall or snowmelt, storing it temporarily and then releasing it slowly over time. This reduces the peak flow of rivers and streams, which prevents downstream flooding. For example, in the Mississippi River basin, studies have shown that restoring just a fraction of the original wetlands could significantly lower flood levels in cities like St. Louis. However, over the past century, many wetlands have been drained for agriculture or urban development. This has removed that natural buffer, making floods more severe. So, when we think about flood prevention, we need to consider not just engineered solutions like levees, but also the preservation and restoration of natural landscapes."