北京的水危机和出路(英文)

Beijing’s Way Out of Water Crisis Current Water Supplies to BeijingBeijing obtains its municipal water supplies from reservoirs and more importantly from groundwater (including their “blend”). The latter refers to approximately more than 30,000 pumping wells, which satisfy most of the city’s industrial, agricultural and urban water demands. Compared with the well-protected, high-quality water in reservoirs (e.g. Miyun Reservoir and Guanting Reservoir), the conditions of groundwater are more complicated – since the area slopes toward the southeast, the water quality in its northern part is fine with lower hardness, while water in its southern and southeastern parts is saltier, harder, mixed with more impurity and even brackish on some plots (e.g. in Fengtai District). The case of shallow groundwater is still worse –harmful to health with brackish taste and higher TDS, hardness and nitrate level than the national standards. Therefore, the quality of Beijing’s municipal water varies strikingly with locations and water supplies, with that of some southern and southeastern plots badly in need of improvement.Beijing now obtains 70% of its municipal water supplies from surface water, and 30% from groundwater. A major concern is that the average CODmn of our surface water is 4-6, higher than the level (2-4) required for class-Ⅱwater quality. At the end of 2006, we formulated a new standard for municipal water supplies, increasing its items from 35 to 106. Among the 106 items, 42 are for compulsory routine inspection, and the other 64 in abeyance. All these items will come into effect on July 1, 2012.Purification Process Used by Waterworks90% of the purification process in our waterworks refers to traditional methods, including coagulating sedimentation, filtration and disinfection. Such methods have been used for a century – for instance, by a waterworks on the Huangpu River, Shanghai for more than 110 years. The old process shows no consideration of the ever-increased organic pollutants, and only 30% of such pollutants can be treated.Existing Water Pipe Networks in BeijingThe total length of water supply pipes in Beijing is 1,6796 km, of which 6% were built before 1953, 8% in 1954-1965, 13% in 1966-1978, 38% in 1979-1995 and 35% after 1996. In terms of material, 51% of these pipes are made of grey cast iron, 13% cement, 6% galvanized iron, 17% nodular cast iron, 8% steel and 5% PVC.Secondary Pollution of Municipal WaterWater quality may directly impact everyone’s health. Poor materials may result in secondary pollution of municipal water, which must be taken seriously.Chlorine pollutants – They mainly refer to the residue of chlorination, and may compound with water into chloroform and carbon tetrachloride, which may lead to metrocarcinoma and cervical carcinoma, decrease leukocytes and thus lead to liver cancer, and easily cause hypertension, obesity, etc. for children.Corrosion – It is caused by oxidation reaction, and may overload the renal system and cause endocrine dyscrasia, hypertension, etc.Heavy metals – They mainly include mercury, lead, arsenic, cadmium, etc. that come from water pumping and piping. Such substances may overload the liver and renal systems through long-term intake, and easily cause diseases for liver, kidney heart and the nervous system.Water aging – Caused by increased microorganisms, bacteria and decreased minerals, it may have many impacts on human health (e.g. under-cooked food, poorly-watered flowers and awfully-made tea).We may take in harmful substances from municipal water through the following three channels: inhalation when taking baths (1/3); oral intake (1/3); and skin inhalation when cleaning up (1/3).Beijing’s SevereWater ShortageBeijing originated from an ancient ferry on the Yongding River, and water has been furnishing life and vigor to the whole area. But today, we can see no water in most reaches of this river even in wet seasons; we can see neither mists nor ripples but large pieces of farmland at the center of Miyun Reservoir; most reservoirs and rivers will dry up in average seasons, and such well-known waters as Kunming Lake in the Summer Palace, the small lakes in the Old Summer Palace and Weiming Lake on the campus of Peking University will expose their lakebeds in dry seasons.A water crisis is stealing up on us, but we still overlook its possibly severe results. Water shortage has become a major restraint to Beijing’s development, which has been particularly aggravated by successive years of drought since 1999.In 2000, the per capita water resource amount of Beijing was less than 300 m3. That was only 1/8 of the national level of 2,200 m3, and ranked beyond 100th in over 120 capital and major cities across the world. In the plains, over-exploitation of groundwater has caused depression cones with a total coverage of more than 2000 km2. Beijing has become one of the cities that suffer the most desperate shortage of water in the world.In recent years, Beijing has suffered an annual water shortage of around 400 million m3. According to the Overall Plan & Report on the Sustainable Use of Water Resource in Beijing, the area’s water demand in 2010 is estimated at 5,395 million m3, with a shortfall of 1,262 million m3.Beijing – Ever Rich in WaterEver called “Beijing Bay” and ringed on three sides by mountains and one side by plains, Beijing was once rich in water resource, with numerous rivers, lakes and abundant groundwater.Anciently named Yan, Ji or Youzhou, Beijing developed from an important regional center in northern China where a kingdom situated its throne to the capital of several dynasties and the People’s Republic of China. In its history of more than 3,000 years – 800 years as a capital, the city has been bound up with water.200 years ago, there were many lakes, ponds and swamps in Beijing, and the total coverage of wetland was over100 times larger than now. Even in the Qing Dynasty (A.D. 1644-1912), there remained large pieces of wetland in the southern part of the area; for instance, Nanhaizi, a once-existed piece of wetland was then the habitat of the milu deer, a species that liked the humid climate there.As recorded in the ancient book Sceneries in Beijing, “A dian (pond) is where water gathers, and five kilometers northwest of Gaoliang Bridge, fountains flow out of the plains.”And in another book, A Textual Research on the Popular Legendaries, “Dian is a kind of shallow ponds.”There were once ninety-nine such ponds in the area, such as Nan Dian, Bei Dian, Fang Dian, Sanjiao Dian, Da Dian, Xiao Dian, etc. And the Chinese character “hai”means “big”, so the northeastern district Haidian was named after those once-existed big ponds. The place named Bagou was where fountain waters gathered, with twenty-eight of them entitled by the Chinese emperors. The biggest pond in old Haidian was Wengshan Pond. Even today, there remained such waters as Houhai, Jishuitan, Shichahai, Beihai, Zhongnanhai, Toranting, Longtan Lake, Zizhuyuan, Bayi Lake, Liumeng Lake, etc. in downtown Beijing.Therefore, in terms of natural ecosystem, Beijing is not a water-deficient area. If calculated into surface runoff, the water resource amount of Beijing is 243 mm, higher than the global average of 150 mm.If calculated by a multi-year mean total amount of 4,000 million m3, the per capita water resource amount of Beijing was around 60,000 m3 in early Han Dynasty (the 2nd Century B.C.), 28,000 m3 in late Eastern Han Dynasty (the turn of A.D. the 2nd and 3rd Century), 11,000 m3 in the Tang Dynasty (A.D. 618-907), 8,000 m3 in the Jin Dynasty (A.D. 1115-1234), 5,300 m3 in the Yuan Dynasty (A.D. 1279-1368) and Ming Dynasty (A.D. 1368-1644) and 3,600 m3when the city’s population rose to 1.1 million in late Qing Dynasty (around the beginning of the 20th Century).Where the Problem LaysIn 1949, Beijing’s population was around 2.2 million, and its per capita water resource amount was 1,800 m3. Yet by 2007, the population had increased eight times and approached 18 million – 13 years earlier than expected; the urban land had expanded 50 times, and the water demand more than 35 times. Over-rapidly growing water use and city size have over-depleted water resource in the area, making Beijing one of the most water-deficient metropolises in the world.The main surface water supplies of Beijing are Miyun Reservoir and Guangting Reservoir. With a designed storage capacity of 4.37 billion m3, the former stored 710 million m3 of water in 2004, but more than 600 million m3 was unusable; only 100 million m3 of the latter’s designed 4.16 billion m3 capacity was used in 2007, which meant no water to supplied.We can build a megalopolis, but cannot create the natural conditions it relies on. A city’s development, if expected to be sustainable, should go in line with its bearing capacity.With poor knowledge and understanding of the ecosystem, we have seen the agricultural, industrial, urban-use except the ecological dimensions of Beijing’s water resource. Although the city is better embellished, its ecological environment is deteriorating.Facing the mounting demand, we have turned to groundwater, which should have been stored for future generations. Over-exploitation has caused such storage a shortfall of 5.7 billion m3, and depression cones with a total coverage of more than 2000 km2.Beijing is now diverting water from more severely water-deficient regions like Hebei and Shanxi. And the underway South-to-North Water Diversion Project (Middle Route) will annually supply Beijing with 1.2 billion m3 of water from 2010. This is not a wise alternative in the longrun. In 2020, when the city’s population reaches 18-20 million, its per capita water resource amount will be only 250-280 m3– even lower than that in 2000Large-scale, long-distance water diversion may not only perpetuate the city’s current production mode and living style that consume huge amount of resources, but also stimulate the further expansion of its size, thus aggravating its water crisis.To propel Beijing’s sustainable development and solve its water crisis, we should act in line with the local conditions: downsize the city and decrease its population; strictly restrict the scrambling outskirt clusters and high-intensity urban construction; coordinate urban development and the area’s natural and ecological system, and maintain the normal recycle of water resource in the Haihe River Basin; spare no efforts to restore the local eco-system.As for the underway South-to-North Water Diversion Project, the unit amount of water diversion should no longer be enlarged. Meanwhile we should pursue industrial restructuring and the sound development of water-saving, anti-pollution sectors, more efficient use of water resource, reasonable water pricing and no under-utilization of relatively rich resources.To solve Beijing’s water shortage, we should also smash through the barriers of administrative division and work for an optimized, self-organized coordination system involving all cities in the Haihe Basin. These cities’ urban construction and population increase should go in conformity and mutualistic symbiosis with the bearing capacity of water resource in the Basin.Problems of Barreled Water1) Once unsealed, its quality is guaranteed for only 24 hours. Bacteria may breed at a certain temperature and on particular conditions several hours after the barreled water is unsealed, and three days later, the water may be completely re-contaminated.Some relevant government departments ever tested the barreled water unsealed for two weeks, and found that the total bacterial count was over 12.5 times higher than the limit of qualified production.Barrels made of waste CD, VCD or DVD disks may emit fluorescence at night.2) According to a survey, around 200 thousand tons of water on the local market is of unknown origin.3) The price of a barrel that conforms to sanitary standard is around RMB 35, but that of one made of recycled plastics is only around RMB 8. What a “provoking” gap!4) Such fake barreled water can be made with simple devices like water-filling and sealing machines.5) “Though dressed in famous brands, we drink cheap, shoddy water, which is even no better than what flows out of the tap covered with a silk stock.” With a low cost of no more than RMB 2, such water may be priced much higher at RMB 8-10.6) “Shoddy water” refers to tap water directly barreled by dishonest producers. The barrels they use are made of industrial waste, the cancerigenic macromolecule polymer in which may contaminate the water.Like boiled frogs, only many years later may we feel such water’s harm.The Drinking Water System – the Ultimate Solution1) The supply system of drinking water is a form of dual distribution.2) After advanced treatment, the quality of such water conforms to Standard GB5749-2006.3) It is a kind of government or corporate behavior to build the supply system, which requires large amount of initial investment and a long investment cycle.4) Many developed countries launched such projects as early as three decades ago.5) A developing country must make tremendous efforts to build such a system.6) Commercially-available, small-sized and energy-saving drinking water devices are preferred by some enterprises.。