全世界每天有2000公顷土地盐碱化
文章来源:未知 文章作者:enread 发布时间:2014-10-30 05:33 字体: [ ]  进入论坛
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Every day for more than 20 years, an average of 2,000 hectares of irrigated1 land in arid2 and semi-arid areas across 75 countries have been degraded by salt, according to a study by UN University's Canadian-based Institute for Water, Environment and Health, published Oct. 28. Today an area the size of France is affected3 -- about 62 million hectares (20%) of the world's irrigated lands, up from 45 million hectares in the early 1990s.
 
Salt-degradation4 occurs in arid and semi-arid regions where rainfall is too low to maintain regular percolation5 of rainwater through the soil and where irrigation is practiced without a natural or artificial drainage system.
 
Irrigation practices without drainage management trigger the accumulation of salts in the root zone, affecting several soil properties and reducing productivity.
 
"To feed the world's anticipated nine billion people by 2050, and with little new productive land available, it's a case of all lands needed on deck," says principal author Manzoor Qadir, Assistant Director, Water and Human Development, at UN University's Canadian-based Institute for Water, Environment and Health. "We can't afford not to restore the productivity of salt-affected lands."
 
The study, "Economics of Salt-induced Land Degradation and Restoration,"is published Tuesday Oct. 28 in the UN Sustainable Development journal Natural Resources Forum6.
 
Zafar Adeel, Director of UNU-INWEH, notes the UN Food and Agriculture Organization projects a need to produce 70% more food by 2050, including a 50% rise in annual cereal production to about 3 billion tonnes.
 
"Each week the world loses an area larger than Manhattan to salt-degradation. A large portion of the affected areas in developing countries have seen investments made in irrigation and drainage but the infrastructure7 is not properly maintained or managed. Efforts to restore those lands to full productivity are essential as world population and food needs grow, especially in the developing world."


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1 irrigated d5a480a57e6b6336cbbf24f1103448d2     
[医]冲洗的
参考例句:
  • They irrigated their crops with water from this river. 他们用这条小河里的水浇庄稼。
  • A crop can be sown, weeded, irrigated, and fertilized uniformly. 一种作物可以均匀一致地进行播种,除草,灌溉和施肥。
2 arid JejyB     
adj.干旱的;(土地)贫瘠的
参考例句:
  • These trees will shield off arid winds and protect the fields.这些树能挡住旱风,保护农田。
  • There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。
3 affected TzUzg0     
adj.不自然的,假装的
参考例句:
  • She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
  • His manners are affected.他的态度不自然。
4 degradation QxKxL     
n.降级;低落;退化;陵削;降解;衰变
参考例句:
  • There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。
  • Gambling is always coupled with degradation.赌博总是与堕落相联系。
5 percolation 766e454de7819792a2c54a57104a44d4     
n.过滤,浸透;渗滤;渗漏
参考例句:
  • This corresponds to the percolation phase of the drying mechanism. 这相当于干化机理的渗滤阶段。 来自辞典例句
  • The percolation clusters with various occupying probability are constructed. 构造了具有不同占据概率的逾渗集团。 来自互联网
6 forum cilx0     
n.论坛,讨论会
参考例句:
  • They're holding a forum on new ways of teaching history.他们正在举行历史教学讨论会。
  • The organisation would provide a forum where problems could be discussed.这个组织将提供一个可以讨论问题的平台。
7 infrastructure UbBz5     
n.下部构造,下部组织,基础结构,基础设施
参考例句:
  • We should step up the development of infrastructure for research.加强科学基础设施建设。
  • We should strengthen cultural infrastructure and boost various types of popular culture.加强文化基础设施建设,发展各类群众文化。
TAG标签: population land salt
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