大学英语作文:21世纪的水质 Water quality in twenty-first Century

Water of the 21st Century

第二十一世纪的水

Life on earth depends on water,and there is no substitute for it. The current assumption is that our basic needs for water-whether for drinking, agriculture, industry or the raising of fish--will always have to be met. Given that premise, there are two basic routes we can go. more equitable access to water or more drastic engineering solutions. Looking at the engineering solution first, a lot of my research concentrates on what happens to wetlands when you build dams in river basins, particularly in Africa. The ecology of such areas is almost entirely driven by the seasonal change of the river--the pulse of the water. And the fact is that if you build a dam, you generally wreck the downstream ecology. In the past, such problems have been hidden by a lack of information. But in the next century, governments will have no excuse for their blissful ignorance. The engineers ability to control water flows has created new kinds of unpredictability too. Dams in Africa have meant fewer fish, less grazing and less floodplain agriculture--none of which were anticipated. And their average economic life is assumed to be thirty years. Dams dont exist for ever, but what will replace them is not clear. The key issue in any discussion of water is money. To talk about a water crisis hides intractable problems such as poverty. Consider the problems of water supply in Mexico City or Delhi. If you re rich, you drink mineral water and may even have a swimming-pool--yet millions in such cities cant get safe drinking water. people talk about the coming water crisis. I believe we have one now. It is a water crisis for the poor.

地球上的生命取决于水，没有任何替代品。目前的假设是，我们的基本需求是水，无论是饮用水，农业，工业还是鱼的养殖--都必须满足。既然有这样的前提，我们可以走两条基本路线。更公平地获得水或更激烈的工程解决方案。在工程解决方案的第一，我的研究集中在什么情况下，当你在河流域，特别是在非洲建设的湿地发生了什么。这类地区的生态环境几乎完全被季节变化所驱动--水的脉搏。而事实是，如果你建一座水坝，你一般会破坏下游的生态环境。在过去，这样的问题已经被隐藏的信息缺乏。但在下个世纪，政府将没有任何借口为自己的无知。工程师们控制水流的能力也创造了新的不可预测性。在非洲的水坝意味着更少的鱼，更少的放牧和更少的洪泛区农业--没有一个被预期。他们的平均经济生活被假定为三十年。大坝不存在，但什么将取代它们是不明确的。水的任何讨论中的关键问题是金钱。谈论水危机隐藏棘手的问题，如贫困。考虑墨西哥市或德里的供水问题。如果你很富有，你喝矿泉水，甚至可能有一个游泳池，但数以百万计的人在这样的城市不能得到安全饮用水。人们谈论即将到来的水危机。我相信我们现在有一个。这是一个贫穷的水危机。