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【分享】Applied Hydrogeophysics【已搜无重复】
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Soils and groundwater are important natural resources that sustain life on Earth. In the last century, the enormous expansion of industrial and agricultural activities has led to an increased environmental pressure on these systems. Soils and groundwater are extremely important because they yield much of our water resources and sustain food production for humanity. Agricultural activities consume nearly 80% of the fresh water used throughout the world, and the majority of this water is used for irrigation. In many countries aquifers are used as the major source of water for this purpose. Irrigation of cropland has greatly increased food production, but has also had some drawbacks due to the amount of water drawn from aquifers. Some of the major problems related with irrigation are excessive leaching of nutrients and pesticides, depletion of aquifers, ground subsidence, and soil salinization http://www.mediafire.com/?rd5yt3hyg0d [ Last edited by ewigkeit on 2008-3-26 at 13:40 ] |
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