THREE GORGES DAM

The 'Three Gorges Dam' () is a Chinese hydroelectric river dam which spans the Yangtze River in Sandouping, Yichang, Hubei province, China. As of 2007, it is the largest hydroelectric river dam in the world, more than five times the size of the Hoover Dam.

The dam is made of concrete and is about 2335 meters (7660 ft) long, and 185 meters (616 ft) high. In comparison, the towers of the Golden Gate Bridge in San Francisco, USA, are 227.4 meters tall. The dam is 115 meters wide on the bottom and 40 meters wide on top. The whole project moved about 134 million cubic meters of earth, used 28 million cubic meters of concrete and 463 thousand tons of steel, which is enough to build 63 Eiffel Towers. The reservoir is over 600 km long and can hold 39.3 cubic kilometers of water. The total capacity will reach 22 500 MW and claim the title to being the largest hydro-electric power station in the world. Although, the expected annual electricity generation would be about 84.7 TWh, making the dam the second largest hydroelectricity generator in the world (after Itaipu in South America).

The original idea of this dam was created by Sun Yat-sen in his 'The International Development of China' in 1919. After PRC was founded, several leaders were tempted to start the dam, but with limited ability, they started the Gezhouba Dam dam first.
After the approval from the National People's Congress in April 3 1992, the project was finally on the way to completion.
Construction began in 1994 and structural work was finished on May 20, 2006, nine months ahead of schedule. Three Gorges dam wall completed
The reservoir began filling on June 1, 2003, and will occupy part of the scenic Three Gorges area, between the cities of Yichang, Hubei; and Fuling, Chongqing. However, several generators still have to be installed, and the dam is not expected to become fully operational until about 2009.




As with many dams, there is a debate over the costs and benefits of the Three Gorges Dam. Although there are economic benefits from flood control and hydroelectric power, there are also concerns about the future of 1.13 million people who will be displaced by the rising waters, the loss of many valuable archaeological and cultural sites, as well as the effects on the environment.

Contents

Costs and funding sources

Advantages

Power production

Flood control and drought

Navigation

Future projects upstream

Criticism

Greenhouse gases

Impact on ecosystem

Effect on local culture and aesthetic values

Sedimentation

Military risks

In fiction

See also

References

External links

Costs and funding sources

When finished, the project will have cost no more than 180 billion yuan (22.5 billion U.S. dollars), 20 billion yuan less than the initial estimated budget of 203.9 billion yuan (25.2 billion U.S. dollars). This calculation accounts for the effect of inflation, and the lower costs are attributed to a low inflation rate in recent years. Brief explan of TGP It is estimated that the cost of construction will be recovered when the dam generates 1000 TWh of the electricity, which will be sold at the price of 250 billion yuan. This will take about 10 more years.
Sources for funding include the Three Gorges Dam Construction Fund, revenue from Gezhouba Dam, policy loans from the China Development Bank, loans from domestic and foreign commercial banks, corporate bonds, and revenue from Three Gorges Dam before and after fully operation, with additional charges in electricity contributing to the Three Gorges Construction Fund. The additional charges are as follows: Every province receiving power from the Three Gorges Dam has to pay an additional charge of ¥7.00(US $0.90) per MWh. Provinces that won't receive power from the Three Gorges Dam have to pay an additional charge of ¥4.00(US $0.51) per MWh. Tibet doesn't have to pay any additional money.
Three Gorges Dam

Advantages

Power production

The Three Gorges Dam is the world's biggest hydro-electric power station by total capacity: its total capacity is 22,500 MW. It will have 32 generators in total, each with a capacity of 700 MW. Fourteen are installed in the north side of the dam, Twelve in the south side and the remaining six in the underground power plant in the mountain south of the dam. After completion, the expected annual electricity generation would be about 84.7 TWh, making the dam the second largest hydroelectricity generator in the world (after Itaipu in South America).

According to The National Development and Reform Commission of China, the average consumption of coal to produce one kWh of electricity in China is 366 grams (2006). Three Gorges Dam Therefore, the Three Gorges Dam will potentially reduce the coal consumption by 31 million tons per year, cutting the emission of 100 million tons of greenhouse gas,
Greenhouse Gas Emissions By Country , millions of tons of dust, 1 million tons of sulfur dioxide, 370 thousand tons of nitric oxide, 10 thousand tons of carbon monoxide and a significant amount of mercury into the atmosphere. Three Gorges Dam According to Xinhua Net, up until 12 AM May 14, 2007, the Three Gorges Dam has produced over 160 TWh of electricity in total.
Three Gorges Dam
The 14 generators in north side of the dam have already been installed and they first ran in full power 9800 MW mode on October 18th 2006 after the water level had been raised to 156 m. Three Gorges Dam
The 10 generators in south side of the dam are currently being installed. The third generator in the south side (No. 21) started working on August 20 2007, bringing the total capacity of the dam to 11.9 GW. The underground power plant with six generators is still under construction.
The electricity generated by the Three Gorges Dam project is sold to the State Grid Corporation at a rate of ¥250 per MWh ($32.5 US). Nine provinces and 2 cities consume the power from it, including Shanghai. Power is sent in three directions.The 500 kV DC transmission line to the East China Grid has a capacity of 7,200 MW. The 500 kV AC transmission line to Central China Grid has a capacity of 12 GW. The other 500 kV DC transmission line to South China Grid has a capacity of 3 GW and supplies Guangdong.
In the original plan, it was expected to provide 10% of electricity consumption in China. However, China's demand for electricity has increased at a higher rate than was planned, and if fully operational now, it would support about 3% of the total electricity consumption in China.
Three Gorges Dam

Annual Production of Energy

Year	Number of installed units	GWh
2003	6	8,607
2004	11	39,155
2005	14	49,090
2006	14	49,250
2007	17	43,898
Total	17 (32)	190,000

Flood control and drought

The most significant function of the dam is to control flooding. There are millions of people living downstream of the Three Gorges Dam Project. Many big and important cities like Wuhan, Nanjing and Shanghai were built just beside the river. Plenty of farm land and the most important industrial area of China is built beside the Yangtze River. Flooding is a major problem of a seasonal river like the Yangtze.
In 1954, 47.75 million acres (193,000 km²) of land was flooded, killing 33,169 people and forcing 18,884,000 people to move. The flood covered Wuhan, a city with 8 million people, for over three months, and the Jingguang Railway was out of order for more than 100 days.
In 1998, a flood in the same area caused damage in the range of billions of dollars. The Chinese government asked support from its military to fight against the flooding. Two thousand and thirty-nine square kilometers of farm land was flooded. Over 2.3 million people were affected by the flood and 1526 of them were killed. Three Gorges Dam
The reservoir's flood storage capacity is 22 cubic kilometers (18 million acre feet). This capacity will lessen the frequency of big downstream flooding from once every 10 years to once every 100 years. With the dam, it is expected that major floods can be controlled. If a "super" flood comes, the dam can minimize the impact of it.

Navigation

Ship locks for river traffic to bypass the Three Gorges Dam, May 2004

The installation of ship locks is intended to increase river shipping from 10 million to 50 million tonnes annually, with transportation costs cut by 30 to 37%. Shipping will become safer, since the gorges are notoriously dangerous to navigate. Each ship lock is made up of 5 stages taking around 4 hours in total to complete. Critics argue, however, that heavy siltation will clog ports such as Chongqing within a few years based on the evidence from other dam projects.
The canal locks are designed to be 280 m long, 35 m wide, and 5 m deep (918 x 114 x 16.4 ft). Three Gorges Dam Its Buildings with Biggest Indices
That is 30 m longer than those on the St Lawrence Seaway, but half as deep.
In addition to the canal locks, the Three Gorges Dam is equipped with a ship lift, a kind of elevator for vessels. The ship lift will be capable of lifting ships of up to 3,000 tons. Three Gorges Shiplift resurfaces China's west seeks to impress investors Ship lift work to begin at Three Gorges site],
In the original plan its capacity was to be 10,000 tons. Three Gorges Probe
The ship lift was not yet complete when the rest of the project was officially opened on May 20 2006. Three Gorges dam ready to go China Completes Three Gorges Dam
On October 3 2006, ''China Daily'' predicted that the shiplift would be completed in 2008. 300,000 more to be relocated from Dam region

Future projects upstream

In order to maximize utility of the Three Gorges Dam and cut down on sedimentation from the Jinshana tributary of the Yangtze river, China plans to build a series of dams upstream of the Yangtze river, including Wudongde, Baihetan, Xiluodu, Xiangjiaba, and downstream of Jinsha. The total capacity of those 4 dams is 38,500 MW, almost double the capacity of the Three Gorges. There are also another 8 dams in the midstream of the Jinsha and 8 more upstream of it.[1]

Criticism

Greenhouse gases

''See also Hydroelectricity''
Although hydro-electric power is a renewable energy source, the creation of large reservoirs can generate considerable quantities of greenhouse gases, including substantial amounts of methane, due to micro-biotic activity that occurs when plants rot. Methane emissions have an intrinsic greenhouse effect more than 20 times as powerful as an equal mass of carbon dioxide emissions. US EPA - Methane: Science
Compared to the greenhouse gas emissions of conventional natural gas power plants, emissions from northern reservoirs are typically about 5% of conventional power plants, while emissions from tropical reservoirs are typically 30%.^[1]

Impact on ecosystem

The reservoirs of water created by dams alter the ecosystem and threaten certain species. The Chinese River Dolphin is already "functionally extinct",^[2]. The Chinese paddlefish is on the edge of extinction and will lose habitat and suffer divided populations (leading to post-zygotic speciation) due to dams such as this. Of the 3,000 to 4,000 remaining critically endangered Siberian Crane, a large number currently spend the winter in wetlands that will be destroyed by the Three Gorges Dam. While logging in the area was required for construction which adds to erosion, stopping the periodic and uncontrolled flooding of the river will lessen bank erosion in the long run. The build up of silt in the reservoir will, however, reduce the amount of silt transported by the Yangtze River to the Yangtze Delta and could reduce the effectiveness of the dam for electricity generation and, perhaps more importantly, the lack of silt deposited in the peninsula could result in erosion and sinking of coastal areas.

Effect on local culture and aesthetic values

In total, 1.13 million people will have to be relocated. This amounts to about 1.23% of the population of those two provinces where the reservoir covers.
The 600 km (375 mile) long reservoir will inundate some 1,300 archaeological sites and alter the appearance of the Three Gorges as the water level rises to some degree, at places for over a hundred meters. Cultural and historical relics are being moved to higher ground as they are discovered but the flooding of the Gorge will undoubtedly cover some undiscovered relics. Some other sites cannot be moved because of their size or design.
These historical sites contain remnants of the homeland of the Ba, an ancient people who settled in the region more than 4,000 years ago. One of the traditions of the Ba was to bury the dead in coffins in caves high on the cliff, some of which will soon be submerged, others will be left unaffected.

Sedimentation

There are two hazards uniquely identified with the dam:^[3] One is that sedimentation modeling is unverified and the other is that the dam sits on a seismic fault.
Excessive sedimentation can block the sluice gates which can cause dam failure under some conditions. This was a contributing cause of the Banqiao Dam failure in 1975 that precipitated the failure of 61 other dams and resulted in over 200,000 deaths. Critics believe that the Yangtze will add 530 million tons of silt into the reservoir on average per year; in time, this silt would pile up behind the walls of the dam, clogging the turbines' entranceway. Further, the absence of silt down stream would have two dramatic effects:

★ Unburdened by silt, the Yangtze below the dam would flow more quickly. This, in turn, would cause the river to scour the banks and riverbed more severely, even to the point of altering the character and predictability of the river itself. In addition, flood diversion dikes along the river would require expensive and continual re-strengthening and rebuilding.

★ The city of Shanghai, more than one thousand miles (1600 km) away from the dam, rests on a massive plain of sediment. The ''"arriving silt -- so long as it does arrive -- strengthens the bed on which Shanghai is built... the less the tonnage of arriving sentiment the more vulnerable is this biggest of Chinese cities to inundation..."'' ^[4]
Also, the weight of the dam and reservoir can theoretically cause induced seismicity, as happened with the Katse Dam in Lesotho. Yet others point out that similar criticism, purely theoretical in nature, have never been leveled at other "mega-dams" such as the Nile's Aswan Dam or the Itaipu Dam in Brazil.

Military risks

In an annual report
to the United States Congress, the Department of Defense cited that in Taiwan, "''proponents of strikes against the mainland apparently hope that merely presenting credible threats to China's urban population or high-value targets, such as the Three Gorges Dam, will deter Chinese military coercion.''" Annual report on the military power of the People's Republic of China (.pdf)
The notion that the Military of the Republic of China would seek to destroy the Dam provoked an angry response from the mainland China media. People's Liberation Army General Liu Yuan was quoted in the China Youth Daily saying that the People's Republic of China would be "seriously on guard against threats from Taiwan independence terrorists". Troops sent to protect China dam

In fiction

★ In Max Brooks' novel World War Z, the large artificial lake upstream of the Three Gorges Dam is the site of the initial zombie outbreak before the war. Later in the novel, the Dam is overrun by zombie hordes, which make the emergency pressure release valves impossible to reach. This eventually results in the Three Gorges Dam rupturing, resulting in a massive tidal wave which races to the ocean, destroying what remains of Wuhan, Nanjing, and Shanghai.

★ In the video game ''Civilization IV'', the Three Gorges Dam is one of the "world wonders" that a civilization can construct. However, the graphical representation of the dam is clearly modeled after the Hoover Dam (which was a wonder feature in previous ''Civilization'' games).

★ In the video game '', the Three Gorges Dam is destroyed by both the Chinese and by a fictional terrorist group in alternate plot lines. The series was banned in China.^[5]

★ Jia Zhangke's film Still Life describes the destiny of two couples with connections to the dam.

★ In the novel ''Dragon Bones,'' by Lisa See, a murder investigation takes place at the Three Gorges Dam.

See also

★ Shibaozhai

References

1. Greenhouse Gas Emissions - Fluxes and Processes, Tremblay, Varfalvy, Roehm and Garneau, , , Springer, 2005, ISBN 3-540-23455-1
2. The Chinese river dolphin is functionally extinct
3. Topping, Audrey Ronning. Environmental controversy over the Three Gorges Dam. Earth Times News Service.
4. Winchester, Simon, ''The River at the Center of the World''(Henry Holt & Co. NY 1998)p.228
5. Swedish video game banned for harming China's sovereignty


Article by ABB on use of HVDC-technology for distribution of power generated at the Three Gorges Dam
"Three Gorges dam's social impact" by Jill McGivering, ''BBC News'', May 20 2006, retrieved May 20 2006

External links

★ Chinese government press release

★ China Digital Times' coverage on Three Gorges Dam

★ China Yangtze Power Co. Ltd.

★ Official site of Three Gorge Project Co. Ltd.

★ Three Gorges Dam

★ International Rivers Network

★ BBC News Online - Troops to protect dam against terrorists - 14 September 2004.

★ BBC News Online - Dam wall completed - 20 May 2006.

★ BBC News Online - In pictures: Three Gorges Dam - 20 May 2006.

★ chinadialogue 中国与世界，环境危机大家谈 - article about the politics of water in China

★ Mao Pin Xi Dam, A part of the Three Gorges Dam

★ Probe International, anti dam web site

★ Information on state power network

★ Bill Zorn Photo Documentary

★ Three Gorges Dam Project photographs of Canadian Photographer Edward Burtynsky. Click on "THREE GORGES" link.

★ Photos from Three Gorges Dam Group on Flickr

★ Megaprojects and risk