設為首頁 - 加入收藏 轉到 移動版
廣告 1000x90
您的當前位置:主頁 > 英語學習 > 英語美文 > 正文

Water of the 21st Century21世紀水資源

來源:apple 編輯:apple 時間:2017-05-17

Water of the 21st Century21世紀水資源
     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.JOOZONE.COM
     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 don't 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 can't 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.

Water of the 21st Century21世紀水資源
地球上的生命依賴于水,而且水是無法替代的。  目前人們的假設是,不管是飲用水還是農業、工業、漁業用水,我們對水的基本需要能夠得到滿足。在這一前提下,我們有兩條基本道路可走:更合理地利用水資源或建立更多大型的水利工程。
    先來看看水利工程問題。我的大量研究的焦點在于如果你在河谷(尤其是非洲河谷)建立大壩,這會對濕地產生什么影響。該地區的生態幾乎完全受控于河流的季節性變化——河水的漲落。事實上,如果你在上游建了水壩,通常會破壞下游的生態環境。過去,這類問題由于信息匱乏而鮮為人知。但在下個世紀,政府就不能為自己的盲目樂觀找借口了。
    工程師控制水流的能力產生了新的不可預知的結果。在非洲建水壩意味著漁業減產,草場減產,洪水泛濫區農業產量下降,所有這些都是事先未預料到的。而我們假定水壩的平均經濟效益的壽命為30年,但水壩不會永遠存在,我們還不知什么可以替代它。
    有關水的討論的關鍵在于錢。談論水危機掩飾了諸如貧窮這樣棘手的問題。
    考慮一下墨西哥城或德里的水供應問題。如果你富有,你可以喝礦泉水,甚至于可以擁有一個游泳池——而這些城市數以百萬計的居民卻喝不上安全的飲用水。人們討論著即將到來的水危機。我想我們現在已經有水危機了,這是一場窮人的水危機。

網友評論:

發表評論
請自覺遵守互聯網相關的政策法規,嚴禁發布色情、暴力、反動的言論。
評價:
表情:
用戶名: 驗證碼:點擊我更換圖片
最新評論 進入詳細評論頁

我的英語 www.ccvbe.com 聯系QQ郵箱625233215@qq.com

Copyright ? 2017 我的英語 版權所有 京ICP備09021341號-3

Top 午夜福利视频网站导航|天天啪久久爱免费视频在线|天天鲁在视频在线观看|成人av720p