The Three Gorges Dam
The Three Gorges Dam is a hydroelectric dam that spans the Yangtze River by the town of Sandouping, located in Yiling District, Yichang, Hubei province, China. The Three Gorges Dam is the world's largest power station in terms of installed capacity (22,500 MW). In 2014 the dam generated 98.8 TWh of electricity, setting a new world record by 0.17 TWh previously held by the Itaipú Dam on the Brazil/Paraguay border in 2013 of 98.63. But in 2015, the Itaipu power plant resumed the lead in annual worldwide production, producing 89.5 TWh, while production of Three Gorges was 87 TWh.Except for a ship lift, the dam project was completed and fully functional as of July 4, 2012, when the last of the main water turbines in the underground plant began production. Each main water turbine has a capacity of 700 MW. The dam body was completed in 2006. Coupling the dam's 32 main turbines with two smaller generators (50 MW each) to power the plant itself, the total electric generating capacity of the dam is 22,500 MW.
As well as producing electricity, the dam is intended to increase the Yangtze River's shipping capacity and reduce the potential for floods downstream by providing flood storage space. The Chinese government regards the project as a historic engineering, social and economic success, with the design of state-of-the-art large turbines, and a move toward limiting greenhouse gas emissions. However, the dam flooded archaeological and cultural sites and displaced some 1.3 million people, and is causing significant ecological changes, including an increased risk of landslides. The dam has been a controversial topic both domestically and abroad.
As well as producing electricity, the dam is intended to increase the Yangtze River's shipping capacity and reduce the potential for floods downstream by providing flood storage space. The Chinese government regards the project as a historic engineering, social and economic success, with the design of state-of-the-art large turbines, and a move toward limiting greenhouse gas emissions. However, the dam flooded archaeological and cultural sites and displaced some 1.3 million people, and is causing significant ecological changes, including an increased risk of landslides. The dam has been a controversial topic both domestically and abroad.
Map of the location of the Three Gorges Dam and the most important cities along the Yangtze River
Relocation of residents
As of June 2008, China relocated 1.24 million residents (ending with Gaoyang in Hubei Province) as 13 cities, 140 towns and 1350 villages either flooded or were partially flooded by the reservoir [A_2-M:CR3-1HP:S-15], about 1.5% of the province's 60.3 million and Chongqing Municipality's 31.44 million population. About 140,000 residents were relocated to other provinces.
Relocation was completed on July 22, 2008. Some 2007 reports claimed that Chongqing Municipality will encourage an additional four million people to move away from the dam to the main urban area of Chongqing by 2020. However, the municipal government explained that the relocation is due to urbanization, rather than the dam, and people involved included other areas of the municipality.
Allegedly, funds for relocating 13,000 farmers around Gaoyang disappeared after being sent to the local government, leaving residents without compensation.
The 600 km (370 mi) long reservoir flooded some 1,300 archaeological sites and altered the appearance of the Three Gorges as the water level rose over 300 ft (91 m). Cultural and historical relics are being moved to higher ground as they are discovered, but the flooding inevitably covered undiscovered relics. Some sites could not be moved because of their location, size, or design. For example, the hanging coffins site high in the Shen Nong Gorge is part of the cliffs
As of June 2008, China relocated 1.24 million residents (ending with Gaoyang in Hubei Province) as 13 cities, 140 towns and 1350 villages either flooded or were partially flooded by the reservoir [A_2-M:CR3-1HP:S-15], about 1.5% of the province's 60.3 million and Chongqing Municipality's 31.44 million population. About 140,000 residents were relocated to other provinces.
Relocation was completed on July 22, 2008. Some 2007 reports claimed that Chongqing Municipality will encourage an additional four million people to move away from the dam to the main urban area of Chongqing by 2020. However, the municipal government explained that the relocation is due to urbanization, rather than the dam, and people involved included other areas of the municipality.
Allegedly, funds for relocating 13,000 farmers around Gaoyang disappeared after being sent to the local government, leaving residents without compensation.
The 600 km (370 mi) long reservoir flooded some 1,300 archaeological sites and altered the appearance of the Three Gorges as the water level rose over 300 ft (91 m). Cultural and historical relics are being moved to higher ground as they are discovered, but the flooding inevitably covered undiscovered relics. Some sites could not be moved because of their location, size, or design. For example, the hanging coffins site high in the Shen Nong Gorge is part of the cliffs
Environmental impact
Emissions
According to the National Development and Reform Commission of China, 366 grams of coal would produce 1 kWh of electricity during 2006. At full power, Three Gorges reduces coal consumption by 31 million tonnes per year, avoiding 100 million tonnes of greenhouse gas emissions, millions of tonnes of dust, one million tonnes of sulfur dioxide, 370,000 tonnes of nitric oxide, 10,000 tonnes of carbon monoxide, and a significant amount of mercury. Hydropower saves the energy needed to mine, wash, and transport the coal from northern China.
From 2003 to 2007, power production equaled that of 84 million tonnes of standard coal, reducing carbon dioxide by 190 million tonnes, sulfur dioxide by 2.29 million tonnes, and nitrogen oxides by 980,000 tonnes.
The dam increased the Yangtze's barge capacity sixfold, reducing carbon dioxide emission by 630,000 tonnes. From 2004 to 2007 a total of 198 million tonnes of goods passed through the ship locks. Compared to using trucking, barges reduced carbon dioxide emission by ten million tonnes and lowered costs by 25%.
Erosion and sedimentation
Two hazards are uniquely identified with the dam. One is that sedimentation projections are not agreed upon, and the other is that the dam sits on a seismic fault. At current levels, 80% of the land in the area is experiencing erosion, depositing about 40 million tons of sediment into the Yangtze annually. Because the flow is slower above the dam, much of this sediment will now settle there instead of flowing downstream, and there will be less sediment downstream.
The absence of silt downstream has three effects:
Some hydrologists expect downstream riverbanks to become more vulnerable to flooding.
Shanghai, more than 1,600 km (990 mi) away, rests on a massive sedimentary plain. The "arriving silt—so long as it does arrive—strengthens the bed on which Shanghai is built... the less the tonnage of arriving sediment the more vulnerable is this biggest of Chinese cities to inundation..." Benthic sediment buildup causes biological damage and reduces aquatic biodiversity.
According to the National Development and Reform Commission of China, 366 grams of coal would produce 1 kWh of electricity during 2006. At full power, Three Gorges reduces coal consumption by 31 million tonnes per year, avoiding 100 million tonnes of greenhouse gas emissions, millions of tonnes of dust, one million tonnes of sulfur dioxide, 370,000 tonnes of nitric oxide, 10,000 tonnes of carbon monoxide, and a significant amount of mercury. Hydropower saves the energy needed to mine, wash, and transport the coal from northern China.
From 2003 to 2007, power production equaled that of 84 million tonnes of standard coal, reducing carbon dioxide by 190 million tonnes, sulfur dioxide by 2.29 million tonnes, and nitrogen oxides by 980,000 tonnes.
The dam increased the Yangtze's barge capacity sixfold, reducing carbon dioxide emission by 630,000 tonnes. From 2004 to 2007 a total of 198 million tonnes of goods passed through the ship locks. Compared to using trucking, barges reduced carbon dioxide emission by ten million tonnes and lowered costs by 25%.
Erosion and sedimentation
Two hazards are uniquely identified with the dam. One is that sedimentation projections are not agreed upon, and the other is that the dam sits on a seismic fault. At current levels, 80% of the land in the area is experiencing erosion, depositing about 40 million tons of sediment into the Yangtze annually. Because the flow is slower above the dam, much of this sediment will now settle there instead of flowing downstream, and there will be less sediment downstream.
The absence of silt downstream has three effects:
Some hydrologists expect downstream riverbanks to become more vulnerable to flooding.
Shanghai, more than 1,600 km (990 mi) away, rests on a massive sedimentary plain. The "arriving silt—so long as it does arrive—strengthens the bed on which Shanghai is built... the less the tonnage of arriving sediment the more vulnerable is this biggest of Chinese cities to inundation..." Benthic sediment buildup causes biological damage and reduces aquatic biodiversity.
Earthquakes and landslides
Erosion in the reservoir, induced by rising water, causes frequent major landslides that have led to noticeable disturbance in the reservoir surface, including two incidents in May 2009 when somewhere between 20,000 and 50,000 cubic metres (26,000 and 65,000 cu yd) of material plunged into the flooded Wuxia Gorge of the Wu River. Also, in the first four months of 2010, there were 97 significant landslides. Waste management The dam catalyzed improved upstream wastewater treatment around Chongqing and its suburban areas. According to the Ministry of Environmental Protection, as of April 2007 more than 50 new plants could treat 1.84 million tonnes per day, 65% of the total need. About 32 landfills were added, which could handle 7,664.5 tonnes of solid waste every day.Over one billion tons of wastewater are released annually into the river, which was more likely to be swept away before the reservoir was created. This has left the water looking stagnant, polluted and murky. To the right: Satellite map showing areas flooded by the Three Gorges reservoir. Compare November 7, 2006 (above) with April 17, 1987 (below)
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Forest cover
In 1997 the Three Gorges area had 10% forestation, down from 20% in the 1950s. Research by the United Nations Food and Agriculture Organization research suggested that the Asia-Pacific region would, overall, gain about 6,000 square kilometers of forest by 2008. That is quite a turnaround from the 13,000 square kilometers net loss of forest each year in the 1990s. The main reason is China's huge reforestation effort. This accelerated after the 1998 Yangtze River floods convinced the government that it must restore tree cover, especially in the Yangtze's basin upstream of the Three Gorges Dam.
Wildlife
Concerns about the potential wildlife impact of the Dam predate the National People's Congress's approval in 1992. This region has long been known for its rich biodiversity. It is home to 6,388 species of plants, which belong to 238 families and 1508 genera. Of these plant species, 57 percent are endangered. These rare species are also used as ingredients in traditional Chinese medicines. Already, the percentage of forested area in the region surrounding the Three Gorges Dam has dropped from twenty percent in 1950 to less than ten percent as of 2002, negatively affecting all plant species in this locality. The region also provides habitats to hundreds of freshwater and terrestrial animal species. Freshwater fish are especially affected by dams due to changes in the water temperature and flow regime. Many other fish are hurt in the turbine blades of the hydroelectric plants as well. This is particularly detrimental to the ecosystem of the region because the Yangtze River basin is home to 361 different fish species and accounts for twenty-seven percent of all endangered freshwater fish species in China. Other aquatic species have been endangered by the dam, particularly the baiji, or Chinese river dolphin, now extinct. In fact, Government Chinese scholars even claim that the Three Gorges Dam directly caused the extinction of the baiji.
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. The dam contributed to the functional extinction of the baiji Yangtze river dolphin. Though it was close to this level even at the start of construction, the dam further decreased its habitat and increased ship travel, which are among the factors causing what will be its ultimate demise. In addition, populations of the Yangtze sturgeon are guaranteed to be "negatively affected" by the dam. Source: Wikipedia
In 1997 the Three Gorges area had 10% forestation, down from 20% in the 1950s. Research by the United Nations Food and Agriculture Organization research suggested that the Asia-Pacific region would, overall, gain about 6,000 square kilometers of forest by 2008. That is quite a turnaround from the 13,000 square kilometers net loss of forest each year in the 1990s. The main reason is China's huge reforestation effort. This accelerated after the 1998 Yangtze River floods convinced the government that it must restore tree cover, especially in the Yangtze's basin upstream of the Three Gorges Dam.
Wildlife
Concerns about the potential wildlife impact of the Dam predate the National People's Congress's approval in 1992. This region has long been known for its rich biodiversity. It is home to 6,388 species of plants, which belong to 238 families and 1508 genera. Of these plant species, 57 percent are endangered. These rare species are also used as ingredients in traditional Chinese medicines. Already, the percentage of forested area in the region surrounding the Three Gorges Dam has dropped from twenty percent in 1950 to less than ten percent as of 2002, negatively affecting all plant species in this locality. The region also provides habitats to hundreds of freshwater and terrestrial animal species. Freshwater fish are especially affected by dams due to changes in the water temperature and flow regime. Many other fish are hurt in the turbine blades of the hydroelectric plants as well. This is particularly detrimental to the ecosystem of the region because the Yangtze River basin is home to 361 different fish species and accounts for twenty-seven percent of all endangered freshwater fish species in China. Other aquatic species have been endangered by the dam, particularly the baiji, or Chinese river dolphin, now extinct. In fact, Government Chinese scholars even claim that the Three Gorges Dam directly caused the extinction of the baiji.
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. The dam contributed to the functional extinction of the baiji Yangtze river dolphin. Though it was close to this level even at the start of construction, the dam further decreased its habitat and increased ship travel, which are among the factors causing what will be its ultimate demise. In addition, populations of the Yangtze sturgeon are guaranteed to be "negatively affected" by the dam. Source: Wikipedia
Vast floating islands of rubbish which threaten to block the world's biggest dam
It is the world's biggest dam which promised to provide environmentally friendly energy to millions.But China's Three Gorges superstructure is now under threat from vast floating islands of rubbish and debris which have been swept into the Yangtze River by torrential rain and flooding.
The debris has clogged a large swathe of the river and the locks of the hydroelectric dam - which cost $25billion to build and claimed more than 100 lives - are now at risk.
The crust of rubbish is jammed so thick in places that people can stand on it.
China has an abysmal environmental record and has had to deal with massive pollution, acid rain and contaminated rivers over the last few years.
Its booming - and in some cases highly toxic - industries have expanded quickly and at a great cost to the environment.
Three Gorges, which has a 1.4 mile long wall, only became fully operational last year and its 26 turbines have a capacity of 18,000 megawats. Around a million people were moved and three cities flooded to create the gargantuan structure and the Chinese viewed it as a flagship environmental project.
The Three Gorges rubbish jam is not an isolated occurrence. Another island covering 15,000 square metres - more than 150,000 square feet - had lodged under a bridge in the north-eastern city of Baishan in Jilin province and was blocking water flow.
Officials in Baishan are racing against time to clear the debris as they fear a fresh wave of flooding could bring down the bridge.
If the island is washed downstream, it could block floodgates at the Yunfeng dam, now operating at full capacity. Emergency services were scrambling to clean up the waterway, near the border with North Korea, but fear it could take days.
'We have collected 40 trucks of the trash, but the remaining trash might fill another 200 trucks,' police officer Wang Yong said.
More rain is forecast in the coming days. In nearby Tonghua city, water supplies were restored on Wednesday, four days after flooding ripped apart pipelines. Jilin has been devastated by floods this summer, with more than 140 people listed as dead or missing over the past two months. Source: Dailymail
The debris has clogged a large swathe of the river and the locks of the hydroelectric dam - which cost $25billion to build and claimed more than 100 lives - are now at risk.
The crust of rubbish is jammed so thick in places that people can stand on it.
China has an abysmal environmental record and has had to deal with massive pollution, acid rain and contaminated rivers over the last few years.
Its booming - and in some cases highly toxic - industries have expanded quickly and at a great cost to the environment.
Three Gorges, which has a 1.4 mile long wall, only became fully operational last year and its 26 turbines have a capacity of 18,000 megawats. Around a million people were moved and three cities flooded to create the gargantuan structure and the Chinese viewed it as a flagship environmental project.
The Three Gorges rubbish jam is not an isolated occurrence. Another island covering 15,000 square metres - more than 150,000 square feet - had lodged under a bridge in the north-eastern city of Baishan in Jilin province and was blocking water flow.
Officials in Baishan are racing against time to clear the debris as they fear a fresh wave of flooding could bring down the bridge.
If the island is washed downstream, it could block floodgates at the Yunfeng dam, now operating at full capacity. Emergency services were scrambling to clean up the waterway, near the border with North Korea, but fear it could take days.
'We have collected 40 trucks of the trash, but the remaining trash might fill another 200 trucks,' police officer Wang Yong said.
More rain is forecast in the coming days. In nearby Tonghua city, water supplies were restored on Wednesday, four days after flooding ripped apart pipelines. Jilin has been devastated by floods this summer, with more than 140 people listed as dead or missing over the past two months. Source: Dailymail