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南水北调

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发表于 4-12-2018 16:48:18 | 显示全部楼层 |阅读模式
Water | A Massive Diversion; The world's largest infrastructure project does more harm than good. Economist, Apr 7, 2018.
https://www.economist.com/news/c ... uilt-worlds-largest

Note:
(a) "FOR the past drought-stricken year, most of the drinking water consumed in Beijing has travelled 1,432km (895 miles), roughly the distance from New York to Orlando, Florida. Its journey begins in a remote and hilly part of central China at the Danjiangkou reservoir 丹江口水库 [大坝 located at 湖北省十堰市丹江口市(汉江/汉水 和 丹江/ 丹水 的交会处)], on the bottom of which lies the drowned city of Junzhou 均州 [named after 均水 -- both now submerged], reputed to be the birthplace of Taoism. The water gushes north by canal and pipeline, crosses the Yellow river by burrowing under it, and arrives, 15 days later, in the water-treatment plants of Beijing. * * * This winter and spring, the reservoir was the capital’s lifeline. No rain or snow fell in Beijing between October 23rd and March 17th—by far the longest drought on record. Yet the city suffered no supply disruptions * * * It [南水北调: two routes, not just the middle route described above] is the largest transfer of water between river basins in [world's] history"

(b) "The route between Beijing and Danjiangkou, which lies on a tributary of the Yangzi, opened in 2014. An eastern route opened in 2013 using the ancient Grand Canal between Hangzhou and the capital. * * * So far these have cost, according to the project’s first director, Zhang Jiyao, 300bn yuan ($48bn)—more than twice their initial budget."
(c) "The capital uses about 3.6bn cubic metres of water a year. The city has 2.1bn in local reservoirs and rivers, and the diversion scheme provides 1.1bn. So the project does not cover the current shortfall, which is made up by underground water."
(d) "Officially, 9.5bn cubic metres of water a year are supposed to be flowing through the middle route. But officials at the headwaters in Danjiangkou say that less than half of the planned extraction was taken out of the reservoir in 2017. * * * [in part] because the reservoir is relatively small: its capacity is 29bn cubic metres. Taking a third of that away each year, engineers worry, would stir up huge quantities of silt [ie, roil the water] * * * the project is operating at less than its [proposed] capacity."
(e) "Because planners worried about pollution, they closed many of the industries lining canals and reservoirs. These included the mainstays of Danjiangkou’s economy: fish farming 网箱水产养殖 and turmeric processing [十堰市郧西县 曾被称为 中国姜黄之乡; not 丹江口市; 姜黄 turmeric 'native to the Indian subcontinent and Southeast Asia': en.wikipedia.org]."
(f) "Downstream from Danjiangkou, pollution has proved intractable. By diverting water from the Yangzi [English: Yangtze], the project has made the [Yangzi] river more sluggish. It has become less able to wash away contaminants and unable to sustain wetlands, which act as sponges and reduce flooding. To compensate for water taken from their rivers, local governments are also building dams wherever they can to divert it back again. Shaanxi province, for example, is damming the Han river to transfer water to its depleted river Wei 渭河 [a tribute to Yellow River, Not Yangzi]. * * **  In Europe 80% of water in industrial processes is recycled. In China the share is half that."
(g) "To give credit where it is due, the government has started to increase water prices to discourage waste. * * * Water from the diversion project is pricier than that from local sources, which in theory should mean it will encourage conservation. The trouble is that [newly imposed] basic tariffs are still too low."

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