经济学人489:水资源

 　　Water

　　水资源
　　All dried up
　　全面干涸
　　Northern China is running out of water, but the government’s remedies are potentially disastrous 1
　　中国北方水资源渐耗尽，政府举措存风险
　　Oct 12th 2013 | BEIJING |From the print edition
　　CHINA endures choking smog, mass destruction of habitats and food poisoned with heavy metals. But ask an environmentalist what is the country’s biggest problem, and the answer is always the same. “Water is the worst,” says Wang Tao, of the Carnegie-Tsinghua Centre in Beijing, “because of its scarcity 2, and because of its pollution.” “Water,” agrees Pan Jiahua, of the Chinese Academy of Social Sciences. “People can’t survive in a desert.” Wang Shucheng, a former water minister, once said: “To fight for every drop of water or die: that is the challenge facing China.”
　　中国正遭受着持续雾霾、栖息地大规模破坏以及食品重金属中毒等问题。然而，当问起环境专家“什么是中国最大的问题”时，得到的答案通常如出一辙。北京清华-卡耐基中心的王涛答道：“水资源问题最为严重，一方面由于水资源缺乏，另一方面由于它的污染状况。” “水资源，”中国社科院潘家华表示认同，“人们不能在沙漠中生存。”前水利部部长汪恕诚曾说：“中国面临的挑战就是要珍惜每一滴水,否则就是灭亡。”
　　He was not exaggerating. A stock image of China is a fisherman and his cormorant 3 on a placid 4 lake. The reality is different. The country uses 600 billion cubic metres (21,200 billion cubic feet) of water a year, or about 400 cubic metres a person—one-quarter of what the average American uses and less than half the international definition of water stress.
　　他并非夸大其词。人们脑海中的中国印象是平静湖面上的渔民和他的鸬鹚。现实却大相径庭。中国水资源的年消耗量达6000亿立方米（212,000亿立方英尺），即约每人400立方米——为美国人平均使用量的四分之一，不到国际公认的用水紧张线的一半。
　　The national average hides an even more alarming regional disparity. Four-fifths of China’s water is in the south, notably 5 the Yangzi river basin. Half the people and two-thirds of the farmland are in the north, including the Yellow River basin. Beijing has the sort of water scarcity usually associated with Saudi Arabia: just 100 cubic metres per person a year. The water table under the capital has dropped by 300 metres (nearly 1,000 feet) since the 1970s.
　　全国平均用水量背后的地区差异更为令人担忧。中国五分之四的水资源位于南方，尤其是长江流域。一半人口以及三分之二的耕地则位于北方，其中包括黄河流域。北京的水荒常被与沙特阿拉伯的相比较：人均年用水量仅为100立方米。自从20世纪70年代以来，首都的地下水位已下降约300米（1,000英尺左右）。
　　China is using up water at an unsustainable rate. Thanks to overuse, rivers simply disappear. The number of rivers with significant catchment areas has fallen from more than 50,000 in the 1950s to 23,000 now. As if that were not bad enough, China is polluting what little water it has left. The Yellow River is often called the cradle of Chinese civilisation 6. In 2007 the Yellow River Conservancy Commission, a government agency, surveyed 13,000 kilometres (8,000 miles) of the river and its tributaries 7 and concluded that a third of the water is unfit even for agriculture. Four thousand petrochemical plants are built on its banks.
　　中国正以一种难以长期持续的速度消耗水资源。过度使用使河流几近干涸。重要集水区的河流数量已从50年代的50,000条减至如今的23,000条。仿佛事态还不够严重，中国仅存的河流也正遭受污染。黄河常被称为中华文明的摇篮。2007年，政府组织黄河保护委员会调查了13,000公里（8,000英里）的黄河及其支流，结论是三分之一的水域不甚健康，甚至无法用于农业生产。4000家石油化工厂矗立黄河两岸。
　　The water available for use is thus atrocious. Song Lanhe, chief engineer for urban water-quality monitoring at the housing ministry 8, says only half the water sources in cities are safe to drink. More than half the groundwater in the north China plain, according to the land ministry, cannot be used for industry, while seven-tenths is unfit for human contact, ie, even for washing. In late 2012 the Chinese media claimed that 300 corpses 9 were found floating in the Yellow River near Lanzhou, the latest of roughly 10,000 victims—most of them (according to the local police) suicides—whose bodies have been washing downstream since the 1960s.
　　可用水如此匮乏。建设部城市水质监测中心总工程师宋兰合说，城市水资源中仅有一半能供人安全饮用。据土地管理局称，超过半数中国北部平原的地下水不能用于工业，同时，七成的水不适于与人体接触，也就是说，这些水甚至无法用于洗涤。2012年下半年，中国媒体曝出在黄河兰州段附近发现300具浮尸。自60年代以来约10,000名新受害者（据当地警方称，其中多为自杀）的尸体顺流而下。
　　In 2009 the World Bank put the overall cost of China’s water crisis at 2.3% of GDP, mostly reflecting damage to health. Water shortages also imperil plans to expand energy production, threatening economic growth. China is hoping to follow America into a shale-gas revolution. But each shale-gas well needs 15,000 tonnes of water a year to run. China is also planning to build around 450 new coal-fired power stations, burning 1.2 billion tonnes of coal a year. The stations have to be cooled by water and the coal has to be washed. The grand total is 9 billion tonnes of water. China does not have that much available. According to the World Resources Institute, a think-tank in Washington, DC, half the new coal-fired plants are to be built in areas of high or extremely high water stress.
　　2009年，世界银行认为中国在水危机上的总支出占GDP的2.3%，这在很大程度上反映出水资源状况对健康之危害。水资源短缺同样危及扩大能源生产，对经济增长造成威胁。中国希望能跟随美国进入天然气时代。然而，一个天然气井需一年15,000吨水来运转。中国也正在计划建造约450座新的燃煤发电站，一年燃烧12亿吨煤炭。发电站需要用水冷却，而煤炭需要用水清洗。总需水量达90亿吨。供不应求。据位于华盛顿的智囊组织世界资源协会称，一半的新燃煤发电站建造于水资源紧缺或极度紧缺的地区。
　　Every drop is precious
　　滴滴珍贵
　　The best answer would be to improve the efficiency with which water is used. Only about 40% of water used in industry is recycled, half as much as in Europe. The rest is dumped in rivers and lakes. Wang Zhansheng of Tsinghua University argues that China is neglecting its urban water infrastructure 10 (sewerage, pipes and water-treatment plants), leading to more waste. Water prices in most cities are only about a tenth of the level in big European cities, yet the government is reluctant to raise them, for fear of a popular backlash.
　　最好的办法是提升水的利用效率。只有约4成工业用水循环使用，该比例仅为欧洲的一半。而余下的则被弃于江河之中。清华大学王占生认为中国忽视城市水利基建（污水、管道和污水净化厂）导致更多浪费。大部分城市的水费仅为欧洲大城市的十分之一，而政府由于担心民众反对，则不愿涨价。
　　The result is that China’s “water productivity” is low. For each cubic metre of water used, China gets $8-worth of output. The average for European countries is $58 per cubic metre. Of course, these countries are richer—but they are not seven times richer.
　　造成的结果是中国的“水分生产率”低下。每立方米水产出值为8美元。而欧洲国家平均产出值为58美元。当然，这些国家更为富有——但不至于富裕七倍。
　　Rather than making sensible and eminently 11 doable reforms in pricing and water conservation, China is focusing on increasing supplies. For decades the country has been ruled by engineers, many of them hydraulic 12 engineers (including the previous president, Hu Jintao). Partly as a result, Communist leaders have reacted to water problems by building engineering projects on a mind-boggling scale.
　　相比合理使用、价格显著调整以及水资源保护，中国采取的主要方法则是增加供应量。几十年来，中国的领导人多为工程师，他们中有不少是水利工程师（包括前国家主席胡锦涛）。部分由于上述原因，共产党领导对水资源问题的反应乃是在令人难以置信的范围内建立工程项目。
　　The best known such project is the Three Gorges 13 dam on the Yangzi. But this year an even vaster project is due to start. Called the South-North Water Diversion Project, it will link the Yangzi with the Yellow River, taking water from the humid south to the parched 14 north. When finished, 3,000km of tunnels and canals will have been drilled through mountains, across plains and under rivers. Its hydrologic and environmental consequences could be enormously harmful.
　　此类工程中最著名的就是位于长江的三峡大坝。但今年一个更大的项目即将启动。南水北调工程将长江与黄河接通，将水从湿润的南方调运至干旱的北方。项目完成后，将有3,000公里的隧道与运河贯通山脉，穿越平原与地下河。它将在水文与环境上造成严重后果。
　　The project links China’s two great rivers through three new channels. The eastern, or downstream one is due to open by the end of this year (see map). It would pump 14.8 billion cubic metres along 1,160km of canals, using in part a 1,500-year-old waterway, the Grand Canal. The water pumped so far has been so polluted that a third of the cost has gone on water treatment. A midstream link, with 1,300km of new canals, is supposed to open by October 2014. That is also when work on the most ambitious and controversial link, the upstream one across the fragile Himalayan plateau, is due to begin. Eventually the South-North project is intended to deliver 45 billion cubic metres of water a year and to cost a total of 486 billion yuan ($79.4 billion). It would be cheaper to desalinate 15 the equivalent amount of seawater.
　　该项目通过三条新水道接通中国两大河流。东部，即下游调水线将于年底贯通（见地图）。它将沿1,160公里的运河（部分利用拥有1500年历史的水道——大运河）输水148亿立方米。迄今输送的水已被污染，以至于三分之一的开支被用于水污染治理。长达1,300千米的中游调水线预计于2014年十月贯通。而最为雄心勃勃和最具争议的上游调水线也预备动工，它贯穿了脆弱的喜马拉雅高原。最终，南水北调工程计划每年调水450亿立方米，总花费4,860亿元人民币（794亿美元）。这比除去等量海水中的盐分的成本来得更低。
　　The environmental damage could be immense. The Yangzi river is already seriously polluted. Chen Jiyu of the Chinese Academy of Engineering told South Weekly, a magazine, in 2012 that the project so far has reduced the quantity of plankton 16 in the Yangzi by over two-thirds and the number of benthic organisms (those living on the river bottom) by half. And that was before it even opened. Ma Jun, China’s best known environmental activist 17, says the government’s predilection 18 for giant engineering projects only makes matters worse, “causing us to hit the limits of our water resources”.
　　这可能造成巨大的环境破坏。长江已被严重污染。2012年，中国工程院院士陈吉余告诉南方周末记者，项目迄今造成长江浮游生物数量减少超过三分之二，底栖生物（生活在水底的生物）减少一半。这还是没有贯通之前所发生的。中国著名环保斗士马军说，政府对大型工程项目的偏好只会让事情变得更糟，“导致我们冲击水资源的使用极限”。
　　But the biggest damage could be political. Proposed dams on the upper reaches of the Brahmaputra, Mekong and other rivers are bound to have an impact on downstream countries, including India, Bangladesh and Vietnam. The Chinese say they would take only 1% of the run-off from the giant Brahmaputra. But if all these projects were operational—and the engineering challenges of one or two of them are so daunting 19 that even the Chinese might balk 20 at them—they would affect the flow of rivers on which a billion people depend. Hence the worries for regional stability. And all this would increase China’s water supplies by a mere 21 7%. The water crisis is driving China to desperate but ultimately unhelpful measures.
　　不过，最大的危害可能是政治上的。计划在雅鲁藏布江、湄公河以及其他河流上游建造的大坝必定会对下游国家产生影响，包括印度、孟加拉国和越南。中国方面说他们仅从广阔的雅鲁藏布江中调取1%的水量。但是如果所有的项目都开始运转——其中一两个工程上的挑战就会令人沮丧，届时中国可能予以回避——这将影响傍河而生的10亿人口。从而导致地区稳定上的隐忧。而所有这些工程仅增加中国供水量的7%。水资源危机迫使中国孤注一掷，而终究未必治本。