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Of the 2.5% of water that is not salty, about 70% is frozen, either at the poles, inglaciers or in permafrost. So all living things, except those in the sea, have about 0.75% of the total to survive on. Most of this available water is underground, in aquifers or similar formations. The rest is falling as rain, sitting in lakes and reservoirsor flowing in rivers where it is, with luck, replaced by rainfall and melting snow andice. There is also, take note, water vapor in the atmosphere.
在這2.5%的不含鹽的水中，約有70%處于冰凍狀態(tài)，儲存在南北兩極、冰川或永久凍土里。因此，除海洋生物之外，所有其他生物只能依賴占總量約0.75%的水生存。這些可用的水大部分在地下，存在于地下蓄水層或類似的結(jié)構(gòu)中。其他部分以雨的形式落下，儲存于湖泊、水庫之中或在江河中流淌，這些江河，如果幸運(yùn)的話，會得到雨水及融化了的冰雪的補(bǔ)充。值得注意的是，還有一部分水蒸發(fā)在大氣中。
The value of water as a commodity of course varies according to locality, purpose and circumstance. Take locality first. Water is not evenly distributed—just nine countries account for 60% of all available fresh supplies—and among them only Brazil, Canada, Colombia, Congo, Indonesia and Russia have an abundance. America is relatively well off, but China and India, with over a third of the world's population between them, have less than 10% of its water.
水作為一種商品，其價(jià)值自然因地域、使用目的與具體情況的差異而有所不同。首先看看地域的影響。水并非均衡分布的——僅9個國家就擁有全部可用淡水的60%——其中僅巴西、加拿大、哥倫比亞、剛果、印度尼西亞和俄羅斯水資源十分豐富。美國的水資源也相對較豐富，而中國和印度，盡管兩國的人口加起來超過世界人口的三分之一，但是所擁有的水資源還不到10%。
Even within countries the variations may be huge. The average annual rainfall in India'snortheast is 110 times that in its western desert. And many places have plenty of water, or even far too much. Flooding is routine, and may become more frequent and damaging with climate change.
即便在各個國家境內(nèi)，水資源分布的差別也可能是巨大的。在印度東北部，年平均降雨雖是西部沙漠地區(qū)的110倍。許多地方有充足的水，甚至水太多了。那樣的地方水災(zāi)成了家常便飯，而且由于氣候的變化，水災(zāi)會越來越頻繁，破壞性也越來越強(qiáng)。
