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. "Now, many of you might think of wetlands as just muddy, mosquito-infested areas, but they actually provide crucial ecosystem services. One of the most important is flood mitigation. Wetlands act like natural sponges. They absorb excess rainwater and slowly release it over time, which reduces the peak flow of rivers and streams during heavy storms. 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 downstream cities. However, over the past century, about half of the world's wetlands have been drained or filled for agriculture and urban development. This loss has made many areas more vulnerable to flooding. So, some governments are now investing in wetland restoration as a cost-effective alternative to building concrete levees and dams. But there's a catch: wetlands need space and time to function properly, and they cannot be created overnight. It takes years for the vegetation and soil to develop the capacity to store water effectively."