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在支撑地球生命存在的诸多条件中,阳光、空气和水是更加基本的从而也是最重要的三大要素。如果再把阳光、空气和水作一番比较,我们又会发现这个世界是缺水的——这里指的是淡水,亦即饮用水——而且不容易得到。世界怎么会缺水呢?世界怎么能不缺水呢?尽管人类居住的地球有70.8%的面积被海洋覆盖着,全球藏水总量约13.7亿立方公里,可是淡水只占2.53%。在所有这些淡水中,又有68.7%储存于南极和北极的冰川及永久性“雪盖”中,人类利用这些淡水资源尚需时日。我们不能不承认,大自然或者说天然的安排都是合理的,因为即便淡水所占的比例是少而又少,但地球上海洋的幅员却是如此广阔,其总量的浩瀚与丰富在通常情况下绝不可能使人类步入缺水的危机。而两极的冰川与“雪盖”自有冻结着的美意:那是留给后人的。问题是:通常情况——正常地使用并爱惜水资源的情况——在人类进入工业社会之后便不复存在。实际上至今在极大多数地球人的心目中,水仍然
Sunshine, air and water are the more basic and therefore the three most important elements in many conditions that support the existence of Earth’s life. If we compare the sunshine, air and water again, we will find that the world is still short of water - in this case, freshwater, that is, drinking water - and it is not readily available. How can the world be short of water? How can the world not lack water? Although 70.8% of the Earth where humans live is covered by oceans, the world’s total water reserves of about 1.37 billion cubic kilometers, but only 2.53% of fresh water. Of all these freshwater, 68.7% are stored in glaciers and permanent snow cover in Antarctica and the Arctic. It takes time for mankind to utilize these freshwater resources. We can not but admit that natural or natural arrangements are reasonable because even though the proportion of freshwater is small and small, the vastness of the oceans on Earth is so vast that the vastness and abundance of their total amount are usually Under no circumstances can human beings be brought into a crisis of lack of water. And the polar glaciers and “snow cover ” own frozen beauty: it is left for future generations. The question is: usually - the normal use and care of water resources - ceases to exist after humanity enters industrial society. In fact, so far in the minds of most Earth people, water remains