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hydroelectric
mimic
Sandra Postel: [---1---]
You are listening to Sandra Postel, she is a former Pew scholar and prolific speaker and author on fresh water issues. [---2-4---]
Sandra Postel: [---5---]
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Sandra Postel: [---7-8---]
You're listening to Sandra Postel.EarthSky is a clear voice for science.
【視聽版科學(xué)小組榮譽(yù)出品】
While dams serve very important purposes for human beings and our societies,controlling floods and providing irrigation water, drinking water, hydroelectric power, they are hard on the environment. Postel said there were 5,000 large dams in the world in 1950, while today there are 45,000. She said something we all know that dams aid humans, but alter natural ecosystems. In this century, she said, it should be possible to implement technologies and more careful planning that balance human and natural needs around large dams. So the idea is to ask, can we develop new rules for how we manage these dams and reservoirs so that they serve not only the traditional functions, but also benefit the ecosystem itself? Postel said the flow of water around dams is often key. With bigger dams the question really is this, is whether we can to some degree mimic the natural pattern of flows that those rivers exhibited before those dams were built? It's very much a current technological challenge.