Аудирование TOEFL

🎧 Транскрипт аудио

Listen to part of a lecture in an environmental science class. The professor is discussing the role of wetlands in flood control. Professor: Wetlands, which include marshes, swamps, and bogs, are often called the 'kidneys of the landscape' because they filter pollutants. But their role in flood mitigation is equally crucial. When heavy rain falls, wetlands act like natural sponges, absorbing excess water and slowly releasing it over time. This reduces the peak flow of rivers and streams, which helps prevent downstream flooding. However, the effectiveness of wetlands depends on their size, soil type, and vegetation density. For example, coastal wetlands can also buffer storm surges, but they have been disappearing at an alarming rate due to urban development and agriculture. In some regions, over 50% of original wetlands have been drained. To address this, restoration projects have reconnected wetlands to rivers, allowing floodplains to function again. Studies show that even small restored wetlands can significantly reduce flood peaks. This is a cost-effective solution compared to building concrete levees, which often fail under extreme conditions.