Comprensión auditiva TOEFL

🎧 Transcripción de audio

Listen to part of a lecture in an environmental science class. The professor is discussing the role of wetlands in flood control. "Now, many people 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. When heavy rain falls, they absorb and slowly release water, reducing the peak flow of rivers downstream. This can prevent catastrophic flooding in urban areas. For example, a study of the Mississippi River basin found that restoring just a fraction of the original wetlands could reduce flood stages by up to a meter. However, over the past century, we have drained and filled many wetlands for agriculture and development, losing over half of the original wetlands in the lower 48 states. This loss has increased flood risks. Interestingly, there's a growing trend of 'managed retreat' — moving levees back and allowing rivers to reconnect with their floodplains. This not only restores wetland habitat but also provides a cost-effective alternative to building higher and stronger levees. So, by working with nature, rather than against it, we can achieve both ecological and economic benefits."