大學(xué)生新聞網(wǎng)
大學(xué)生新聞大學(xué)生活校園文學(xué)大學(xué)生村官
社會實(shí)踐活動社會實(shí)踐經(jīng)歷社會實(shí)踐報告社會實(shí)踐總結(jié)社會實(shí)踐心得
全國排名校友會版軟科排名分類排名本科排名一本排名二本排名專科排名
求職簡歷職場法則面試技巧職場故事求職招聘大學(xué)生就業(yè)
英語學(xué)習(xí)計(jì)算機(jī)學(xué)習(xí)電氣工程機(jī)械工程經(jīng)濟(jì)管理建筑設(shè)計(jì)財務(wù)會計(jì)
申請書證明書檢討書自薦信演講稿心得體會調(diào)查報告讀后感求職信推薦信其它范文
 

Water of the 21st Century

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 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.
    作者:大學(xué)生新聞網(wǎng) 來源:大學(xué)生新聞網(wǎng)
    發(fā)布時間:2023-05-17 瀏覽:
  • 家長和孩子Parents and Kids
  • Many parents who welcome the idea of turning off TV and spending more time with the family are still
  • 05-16 關(guān)注:1
主站蜘蛛池模板: 青草青草久热精品视频在线观看 | 欧美国产中文字幕| 第一福利视频导航| 丰满熟妇乱又伦| 亚洲午夜久久久影院| 伦理eeuss| 国产一区二区三区不卡在线观看| 国产高清一区二区三区视频| 女偶像私下的y荡生活| 最新69堂国产成人精品视频| 精品欧美一区二区三区精品久久| 9lporm自拍视频区在线| 久久香蕉国产线| 人人澡人人澡人人澡| 国产欧美亚洲专区第一页| 女人与公拘交酡全过程i| 最近最好最新2018中文字幕免费 | 永久免费无码网站在线观看个| 羞差的漫画sss| 久久综合热88| 2022国产精品手机在线观看| www久久只有这里有精品| 中文字幕视频在线观看| 久久只有这里的精品69| 九九在线观看精品视频6| 亚洲av日韩综合一区久热| 亚洲欧洲久久久精品| 亚洲精品成人网久久久久久| 人人妻人人狠人人爽| 免费很黄很色裸乳在线观看| 国产精品精品自在线拍| 欧美黄三级在线观看| 美女无遮挡拍拍拍免费视频| 色综合久久天天影视网| 躁天天躁中文字幕在线| 色狠狠狠狠狠香蕉| 精品视频一区二区三区免费| 精品国产v无码大片在线看| 精品无码av无码专区| 玩弄CHINESE丰满人妻VIDEOS| 激情五月激情综合|