久久综合色一综合色88欧美|久久er热在这里只有精品66|国产福利一区二区不卡|日本精品动漫二区三区

    1. <address id="l3apk"><var id="l3apk"><source id="l3apk"></source></var></address>

      21世紀(jì)的水質(zhì)

      時(shí)間:2024-02-27 16:53:51 英語(yǔ)作文 我要投稿
      • 相關(guān)推薦

      21世紀(jì)的水質(zhì)

        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.

      【21世紀(jì)的水質(zhì)】相關(guān)文章:

      水質(zhì)分析調(diào)查報(bào)告-關(guān)于水質(zhì)的調(diào)查報(bào)告04-01

      水質(zhì)環(huán)境分析調(diào)查報(bào)告-水質(zhì)的調(diào)查報(bào)告04-01

      水質(zhì)異常處置工作報(bào)告04-04

      關(guān)于水質(zhì)的調(diào)查報(bào)告10-16

      水質(zhì)檢測(cè)中心的實(shí)習(xí)報(bào)告精選范文12-09

      水質(zhì)化驗(yàn)員辭職報(bào)告05-01

      水質(zhì)調(diào)查暑期社會(huì)實(shí)踐個(gè)人總結(jié)12-09

      大學(xué)生暑期水庫(kù)水質(zhì)調(diào)查工作總結(jié)04-21

      水環(huán)境調(diào)查分析報(bào)告-關(guān)于水質(zhì)的調(diào)查報(bào)告04-02