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ASIAdocument.write(“” + m[today.getMonth()+1]+ ” “+ today.getDate()+”, ” + theYear + ” “);HOMECHINAWORLDBUSINESSLIFESTYLECULTURETRAVELSPORTSOPINIONREGIONALFORUMNEWSPAPERChina Daily PDFChina Daily E-paperChina Daily Global PDFChina Daily Global E-paperOpinion / Op-Ed ContributorsEditorialsOp-EdColumnistsContributorsCartoonsSpecialsFrom the PressForum TrendsTalk from streetDebateEditors Pick:Syrian refugeescyberspaceV-Day paradeshrimp scandalTPPThree Gorges Project doing its job wellBy Zhang Boting (chinadaily.com.cn) Updated:2016-07-05 13:36Comments Print Mail Large Medium SmallThe sluice gates of the Three Gorges Dam. [Photo/Xinhua]Torrential rainfall has hit provinces in the lower reaches of the Yangtze River with water levels rising above the danger level at almost all places. This has prompted many to wonder whether the Three Gorges Project on the Yangtze River is serving its purpose, of alleviating, even preventing natural disasters. There are even rumors that the dam could increase the frequency of geological disasters.
But an undeniable fact is that the Three Gorges Dam has prevented heavy storms and floods from hitting areas in the downstream of the Yangtze River. The El Nino phenomenon this year, which would result in heavy storms in Chinas southern provinces and serious droughts in Southeast and South Asia and South America, has much to do with the high and still increasing carbon emissions worldwide.
As the largest hydropower project in the world, the Three Gorges Dam is helping reduce carbon emission by generating electricity from water instead of fossil fuel. It generates about 100 billion kilowatt hours a year, which means it is saving 50 million tons of steam coal and cutting carbon dioxide emission by about 100 million tons. For a better perspective, the worlds total CO2 emission was 32.3 billion tons in 2014, suggesting the Three Gorges Project can save about 0.3 percent of global CO2 emission.
The Three Gorges Dam has its deficiencies, though. Its storage capacity is not large enough, which limits its capability to adjust the water flow in the Yangtze River. Despite being the worlds hydropower project, its reservoir (39.3 billion cubic meters) ranks 22nd globally. The reservoir is rather small compared with the runoff of the Yangtze River, which is 3,100 cu m per second. The Aswan Dam, the largest in the world, on the Nile River in Egypt has a storage capacity of 168.9 billion cu m while its runoff is only 2,830 cu m per second. And the Hoover Dam in the United States has a storage capacity of about 34.8 billion cubic meters while its runoff is only 311 cu m per second.
The Three Gorges Dams relatively small reservoir has seriously affected its ability to adjust the flow of water in the Yangtze River and thus prevent floods from occurring downstream.
In fact, small reservoirs are a common problem with Chinas dams. Capacity coefficient, or the water storage capacity divided by the average runoff for the passing decades, is an important index of the performance of a reservoir. The average coefficient for reservoirs in Europe and the US is about 0.9 and 0.66, whereas in China it is only slightly above 0.3.
Reservoirs in China are small compared with those in Europe and the US mainly because of limited availability of land. Take the Three Gorges Dam for example. To expand the project, the government would have needed to buy more land along the upper reaches of the river and help more immigrants resettle in other provinces. Besides, the land in the upper reaches of the Three Gorges Dam is mountainous, and it would have cost huge amounts of money and labor to expand the reservoir there. Thats why the Three Gorges Dam was built following the principle of best performance at a given cost.
Chinese engineers are trying to find ways of building multiple reservoirs on the same river. For example, experts and officials are discussing an ambitious plan to build another reservoir in the upper reaches of the Yangtze River at Hutiao Gorge in Southwestern Chinas Yunnan province, and the designed storage capacity would be about 30 billion cu m, comparable to that of the Three Gorges. If the plan becomes reality, floods in the Yangtze River can be further curbed — even in case of extreme weather, it will be easier to control the water flow.
So we should view the Three Gorges Dam as it is. Its job is to help fight climate change by cutting carbon emission, and curb floods in downstream provinces by adjusting the water flow in the Yangtze River. But it alone cannot solve all the problems. There is still a huge gap between Chinas water conservancy projects and those in Europe and the US, and it will take some time for China to catch up with them.
Zhang Boting is a senior researcher at the China Society for Hydropower Engineering. The article is an excerpt from his interview with China Dailys Zhang Zhouxiang.0Related StoriesThree Gorges seeks investorsSpring comes to the Three Gorges areaChina Three Gorges wins bid to operate 2 Brazilian hydropower plantsThe Three Gorges Water Conservancy Project, ChinaElectromechanical Equipment Installation in the Three Gorges Water Conservancy Project, ChinaThree Gorges project generates 800b kWh electricityThree Gorges Dam boosts economyMost Viewed Todays Top NewsLies and exceptions in Manilas caseA short ride to clean, better life and futureChina and EU can accelerate FTA to offset BrexitUpcoming meetings chance to build fire wall against BrexitChina will not swallow bitter pill of humiliationForum TrendsShould campus loans be curbed?Tips for foreigners to get a job in ChinaWould you help adult children buy a home?Tips for new graduates hoping to score a jobFathers Day storyWho cares for left-behind children?Do Chinese women obsess over foreign men?ColumnistsProgress in LGBT civil rights should be contagiousPremarital Sex: Entertainer Kris Wus crisisFeatured ContributorsJakarta must seek common good, not conflict at seaCentral Asia and Uzbekistan are crucial for Chinas Belt and Road InitiativeStar BloggersBrexit: The failure of the European elite By ChevalerieFirst, I shall beware of giving a definitive comment on the British vote. The democratic system ensures that each one is able to participate to vote at its sole discretion. What had to happen finally happened, ineluctable destiny, thats all!Quality of Chinese healthcare By MichaelMTwo days ago, I returned home from a 13 day stay in the hospital in Zhengzhou. I was admitted to Central Hospital of Zhengzhou on June 3. I had surgery the next morning and another one 10 days later.My best friend in China: 35th anniversary of China Daily By subeChina Daily is like a friend who stays with me in every mood in my life. If I am happy, I can write a blog and if I am upset, I can enjoy what others have said and let my feelings go away.SpecialMy China Story MeetupChina Daily, 35 years on: your memoriesPositive energy Leifeng laowai story…| About China Daily | Advertise on Site | Contact Us | Job Offer | Expat Employment |Copyright 1995 -var oTime = new Date();
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