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From its origins in the glacial marshlands of the 20,000-foot high Tibetan plateau, the mighty Yangtze River, or the Changjiang (Long River, as the Chinese call it), winds its way like a giant dragon nearly 6,300 km (3,900 miles) on its way to deposit its annual 960 billion cubic meters of water into the East China Sea. It is the third longest in the world after the Amazon and the Nile, and the third largest in terms of annual runoff after the Amazon and the Congo Rivers. On its journey eastward, the Yangtze passes through an area inhabited by more than 400 million people, approximately one third of the country's population.
But the mighty river has also been the cause of great destruction and loss of life, that devastate the valley. From time immemorial, flooding has been a problem.
The flooding problem has generally been dealt with by constructing levees in the Jingjiang plain area. Since the 1950s, more than 30,000 km of dikes and levees have been reinforced or raised. As sedimentation lifts the river bottom, however, the dikes are continually in danger of being overrun, for the water level during flood season rises 6 to 17 meters higher than that of the plain region along both banks.
The Three Gorge Dams is the largest dam in the world, as wide as the Golden Gate Bridge and twice as tall, capable of generating 18 gigawatts of hydro-electric power.
The idea of building a dam in the gorges has a long history. In 1919, in an article titled "Industrial Plan," Sun Yat-sen, the founding father of modern China, saw the tremendous economic benefits of building a dam on the Yangtze as a part of his economic development plan for China. Dr. Sun was particularly interested in using the vast hydropower resources of the river to produce the electricity needed to build factories for making artificial fertilizer, the only means he could envision for China to make the leap in agricultural productivity needed to feed its growing population.
He also saw the area of the gorges as the most suitable spot for building a dam to generate that electricity. Dr. Sun further elaborated on this idea in 1924, in a lecture he gave on his "Third Principle of the People, Peoples' Livelihood":
An article in the Engineering News-Record, Feb. 28, 1946, reported, "China plans an unprecedented dam for power, irrigation, and navigation on the Yangtze river."
On his visit to China in 1984, President Reagan was asked by the Chinese leadership to increase U.S. involvement in this important project. Reagan, whose outlook, although conservative, was more characteristic of the Roosevelt era, responded forthrightly. He sent his former National Security Advisor, William Clark, to Beijing, as head of a group of people from the Bureau of Reclamation and private industry, with a wide-ranging proposal for collaboration on the Three Gorges Project, proposing, in fact, a U.S.-China consortium to build the dam.
The proposal would have made of the Three Gorges Project a giant joint venture. The Chinese were not so eager to pursue this "joint venture" route in such a strategically important undertaking. Interest in the project from the Reagan Administration quickly cooled, and the joint venture bid was quietly tabled.
Nevertheless, the Reagan visit resulted in the 1984 signing of a five-year agreement between the U.S. Bureau of Reclamation and the Chinese Ministry of Water Resources and Electric Power, to provide technical assistance in the final planning and design phases, and in the construction of the Three Gorges Project. A second agreement was signed in 1992, to provide technical assistance on data management, computer software, drill-hole survey technology, and dam safety monitoring. By that time, however, the environmentalist movement had geared up its campaign to sabotage all U.S. involvement in the Three Gorges Project.
In 1985, the Environmental Policy Institute, the Worldwatch Institute, and other environmentalist groups initiated a major campaign to stymie continued U.S. cooperation with the Three Gorges Project. Hearings were held on Capitol Hill in July 1985 by the Subcommittee on Water and Power Resources of the House Committee on Interior and Insular Affairs, on the topic "Irrigation in Drought and Famine-affected Countries," chaired by Democrat George Miller from California, a darling of the environmentalist lobby.
Although the prime focus of the 1985 hearings of the Subcommittee on Water and Power Resources of the House Committee on Interior and Insular Affairs, was on Africa, the environmentalists focussed on the Three Gorges Project. They demanded that the Bureau of Reclamation submit an environmental impact statement on all its foreign engagements, under the newly legislated domestic requirements of the National Environmental Policy Act (NEPA), which was an environmentalist straitjacket that had been placed on U.S. industry during the Carter Administration.
When the Clinton Administration was elected to office in 1992, the year the Chinese Government actually decided to proceed with the Three Gorges Project,
A year later, (1993) seven environmentalist groups filed a law suit against the U.S. Bureau of Reclamation and the Army Corps of Engineers, charging that the assistance they were rendering the Three Gorges Project would flood the habitats of a dozen "endangered species." The Bureau, a branch of the Interior Department, whose head now was the notorious environmentalist Bruce Babbitt, withdrew from the project that same year.
In 1992, under pressure from the environmentalist lobby, Congress passed legislation which mandated an environmental review for all foreign projects in which the U.S. Export Import Bank was involved. The Three Gorges Project became a test case for this new policy. Because of the significance of the project for U.S.-China relations, Ex-Im asked the National Security Council to convene a panel to consider the merits of U.S. participation in the dam. In September 1995, the interagency National Security Council panel delivered its recommendation, signed by the then Deputy National Security Advisor Sandy Berger. The U.S. government, the panel advised, should not "align itself with a project that raises environmental and human rights concerns on the scale of the Three Gorges." But the memo, leaked to Congress, counselled the government to "refrain from publicly condemning the Three Gorges Project." Instead, it continued, "explanation of our policy should emphasize the U.S. government's commitment to strengthening commercial relations with China and to helping China meet its basic energy needs."
The construction of the dam, begun in September 1994, will take 17 years from its inception, proceeding in three stages. When the dam is completed, it will have a height, or crest, of 185 meters, placing it somewhat higher than the Golden Gate Bridge. In the early phase of operation, during the third phase of construction, the water level in the reservoir region will be 135 meters, and the final Normal Pool Level, or highest level, will be 175 meters.
The first stage of construction, from 1992 to 1997, involved the building of two phase-one cofferdams to shut off the flow of the river from the construction site, and the re-routing of the river through an artificial diversion channel.
Now during phase two, from 1997 to 2003, the construction of the left bank dam section is under way; the left-bank powerhouse will be completed with the installation of some units, and construction of the spillway and continued construction of the permanent shiplock are taking place. The spillway dam, placed in the mid-section of the structure, is 483 meters long with 23 bottom outlets and 22 surface sluice gates. With a maximum discharge capacity of 102,500 cubic meters per second, the project is able to discharge the maximum level of water possible during floods.
In December 2002, before the flood season in the spring of 2003, the phase-three cofferdams in the diversion channel will be finished, and the reservoir water level will be raised to 135 meters. At this time, the permanent shiplock will be ready for use, and the diversion channel will no longer be needed for navigation. According to the scheme for the second stage, 17 million cubic meters of concrete will be poured, 180,000 metal structures will be installed, and approximately $10 billion will be invested.
The water level will be raised to the 135-meter level, creating the reservoir behind it, stretching 600 km back to the city of Chongqing. Construction will continue on building the right bank dam and the second power plant.
By the end of phase three, the water level behind the dam will be raised to its final 175-meter level. The reservoir formed in the upper river will be longer than the Grand Canyon, with an average width of about 1 kilometer, approximately twice the width of the present river. It will have a total storage capacity of 39.3 billion cubic meters including a flood regulation and storage capacity of 22.15 billion cubic meters.
A great deal has been made of the need to resettle as many as 1.2 million people from the lower slopes of the gorges, west of Sandouping, which will be inundated to create the great reservoir behind the dam. The opposition to resettlement, from "human rights" groups to environmentalist groups, has devoted thousands of pages of articles to the plight of the farmers in this region, and the failure of the government to adequately provide a new life for them. There have even been warnings that dissatisfied peasants may rise up in violent revolt against the authorities.
In addition to making the most important environmental improvement—changing the lives of the people—the Three Gorges Dam is part of an overall policy to improve the environment of the Yantgze Valley, including the control of the approximately 500 million tons per year of silt that course down the river.
The possibility of the collection of silt in the huge reservoir to be created by the dam has been a main objection by the dam's opponents. Problems of silt buildup at the Aswan Dam in Egypt, and others around the world, have added to this concern. According to the Chinese, extensive and detailed studies on sedimentation in the reservoir region began in the early 1950s, and concern has increased, as the existing reservoirs and water diversion areas have been filling with silt.
Based on more than 40 years of observations, sediment discharge averages about 526 million tons per year.
The Three Gorges Dam was completed in 2006 on the Yangtze River, and NASA has released images of the flooding reservoir behind the dam which has displaced 1.2 million people.
Taken by astronauts at the International Space Station, images of the Three Gorges Dam reveals “the river is filling up its valley behind the dam to form a narrow reservoir extending more than 600 kilometers.” NASA images from 2000 and 2006 show the changes that have occurred to the Yangtze, especially when compared to the current photographs of the flooding taken in April 2009. The reservoir was filled in three stages, with the last stage occurring in 2009.
After many years of denial, the Chinese government is expressing concern about the environmental consequences of the dam. Scientific American reports:
Chinese officials staged a sudden about-face, acknowledging for the first time that the massive hydroelectric dam, sandwiched between breathtaking cliffs on the Yangtze River in central China, may be triggering landslides, altering entire ecosystems and causing other serious environmental problems—and, by extension, endangering the millions who live in its shadow.
International Rivers warns the environmental impact will be severe and cumulative:
The environmental impacts of the project are profound, and are likely to get worse as time goes on. The submergence of hundreds of factories, mines and waste dumps, and the presence of massive industrial centers upstream are creating a festering bog of effluent, silt, industrial pollutants and rubbish in the reservoir. Erosion of the reservoir and downstream riverbanks is causing landslides, and threatening one of the world’s biggest fisheries in the East China Sea. The weight of the reservoir’s water has many scientists concerned over reservoir-induced seismicity.
Tsunami moves North Pole, shortens daytime Daytime is now 2.68 microseconds shorter because of last month's tsunami.
The massive force unleashed by an earthquake off the coast of Indonesia altered the shape of Earth in a number of minute yet significant ways, NASA scientists have determined.
All earthquakes affect the shape of the planet, but the force of the recent tsunami-inducing quake--the fourth-largest recorded in 100 years--was particularly strong. Benjamin Chao of NASA's Goddard Space Flight Center compared the impact of the quake to the potential impact of the Three Gorges Dam project in China.
If filled, the massive gorge created by the dam would hold 40 cubic kilometers (10 trillion gallons) of water. That shift of mass would increase the length of a day by only 0.06 microseconds and make the Earth only very slightly more round in the middle and flat on the top. It would shift the pole position by about two centimeters (0.8 inches).
"Any worldly event that involves the movement of mass affects the Earth's rotation, from seasonal weather down to driving a car," Chao said in a statement.
It was hailed as one of the engineering feats of the 20th century. Now the Three Gorges Dam across China’s mighty Yangtze River threatens to become an environmental catastrophe.
In an unprecedented admission of blame, Communist Party officials gave a stark warning yesterday of impending disaster in the vast area around the dam if preventive measures are not urgently introduced.
A report issued by the Xinhua news agency, mouthpiece for the Government, said: “There exist many ecological and environmental problems concerning the Three Gorges Dam. If no preventive measures are taken, the project could lead to catastrophe.”
A government forum listed a host of threats such as conflicts over land shortages, ecological deterioration as a result of irrational development and, especially, erosion and landslides on steep hills around the dam. Other authorities have already raised concerns over algae bloom downstream from the Three Gorges and a deterioration in aquatic life.
One official said that the shore of the reservoir had collapsed in 91 places and a total of 36 kilometres (22 miles) had already caved in.
Landslides have produced waves as high as 50 metres (165ft). In July a mountain along a tributary collapsed, dragging 13 farmers to their deaths and drowning 11 fishermen.
Ms Dai told The Times: “The Government knows it has made a mistake. Now they are afraid that the catastrophe that they cannot prevent will spark civil unrest. So they want to go public before the troubles start.”
The Three Gorges Dam will consist of a 610-foot high wall running 1.3 miles from bank to bank.
The reservoir created by the backflow of the dam will extend 360 miles up river to Chongqing ("Chong-ching"), a distance equal to nearly half the length of California.
Once operational, the dam will produce the energy of 15 nuclear power plants.
The project is estimated to be completed in 2009 at a cost of over $30 billion.
In the past 2,000 years, the Yangtze River has experienced 215 catastrophic floods.
In 1998 flooding in the area expected to be controlled by the dam resulted in 4,000 dead, 14 million left homeless and $24 billion in economic loss
When the dam is completed, 13 cities, 140 towns and over 1,300 villages will be submerged by the Three Gorges Reservoir.
To make way for the Three Gorges Dam, 1.5 million people will have to abandon their homes. More than 160,000 citizens have already been relocated.
Upon the dam's completion, 1,300 known archeological sites will be lost forever under water.
Over 265 billion gallons of raw sewage are dumped into the Yangtze annually. Currently the river flushes this downstream and out into the ocean. Upon completion of the Three Gorges project, the sewage will back up in the reservoir.
Over 1,600 factories and abandoned mines will be submerged when the dam is completed. Environmentalists predict that toxins associated with industry and mining will create a hazard for the animals and people who depend on the river for survival.
Over 700 million tons of sediment are deposited into the Yangtze annually, making it the fourth largest sediment carrier in the world. Experts believe that this sediment will build up behind the dam, with only an unproven system of sluice gates to release it.
Over 360 million people live within the watershed of the Yangtze River. If the one in one thousand chance of a dam collapse occured, the millions of people who live downstream would be endangered.
In a rare admission of problems at the giant Three Gorges Dam in central China, officials said cracks found in the dam could leak if not fixed.
Inspectors have found about 80 cracks in the dam's surface, said Pan Jiazhong, head of the construction committee inspection group. He said that while they weren't a threat to safety, they could expand and cause leaking if not repaired.
``If water enters these cracks, there could be negative effects, so we are fixing them very carefully,'' Pan said at a news conference.
Water levels rise in Three Gorges dam, cracks reappear
The closing of the sluice gates comes after a general inspection of the dam in mid-May revealed that repair work to fix large cracks on its 185 metre-high concrete face had not been completely successful.
"We found that some of the vertical cracks on the dam that were repaired have reopened, even though we put a great deal of money and effort into the repair work," Pan Jiazheng, an engineer, said in a speech following the end of the inspection.
Mr Pan, 75, a member of the Academy of Sciences of China and the former deputy director of the Engineering Academy, added, "We should absolutely not be proud of ourselves."
The Three Gorges Dam is situated near six active fault lines and above 15 million people. A dam burst at Three Gorges would, says engineer Philip Williams, president of the San Francisco-based International Rivers Network, "rank as one of history's worst man-made disasters."
The dam is built to withstand earthquakes up to 7.0 on the richter scale, and the largest recent earthquakes have been below 6.0. However, filling the reservoir behind the dam creates seismic pressure which triggers earthquakes. In fact, earthquakes between 6.0 and 6.5 are expected once the reservoir is filled in 2009. One of the dams designed to hold back sedimentation farther up is subject to even worse seismic problems. "
In 1992, the expert group identified 260 landslides and collapses containing at least 100,000 cubic metres of rock and earth; 140 of these had a volume of 1 million cubic metres or more. At least 14 landslides are considered likely to be activated by the filling of the reservoir.
Already major cracks have developed in the dam, and even after extensive repairs, they have reappeared. Pan Jiazheng, one of China's top engineers recently acknowledged,
"It appears that during the concrete pouring, we put too much emphasis on the goal of achieving a very high degree of strength. But it has turned out that a high degree of strength does not necessarily mean good quality in a concrete dam. We have achieved an unnecessarily high degree of strength and a lot of cracks in the dam by pouring too much concrete and spending a great deal of money. "I feel that it's too early to be proud of ourselves, and we have a long way to go.
Over 700 million tons of sediment are deposited into the Yangtze annually, making it the fourth largest sediment carrier in the world. The Chinese officials have decided to halt the flow of sediment higher up in the Yangtze tributaries by building four smaller dams, including one that will be second only to the Three Gorges in size. What will happen when sediment builds up behind these dams?
June 22, 2007 — Two years before its completion, the world’s largest dam is already changing the local weather, say scientists studying the Three Gorges Dam on China’s Yangtze River. Both modeling and actual meteorological data suggest that the reservoir is cooling its valley, which is causing changes in rainfall.
"In China there are a lot of people who complain because of the construction of the dam" and specifically about changes in local weather, said climate modeler Liguang Wu of NASA’s Goddard Space Flight Center and the University of Maryland in College Park.
To find out if the dam was really to blame, Wu and his colleagues collaborated with Chinese scientists to study the changing climate around what will soon be a 401-square-mile reservoir of more than 5 trillion gallons of water and a hydroelectric power plant 20 times more powerful than the Hoover Dam.
The researchers combined satellite data and ground weather stations to create a computer climate simulation, which they then compared to what has already happened in recent years.
The construction of the dam and changes to the land and vegetation around it have been recorded for years by the NASA-US Geological Survey Landsat satellites. They show steady progress from 2000 to today, with the biggest changes in 2004, when the reservoir was partially filled and water backed up into many side canyons.
Among the surprise weather changes has been the increase in rainfall between the Daba and Oinling mountains, said Wu.
The rains come from a "lake effect" intensification of precipitation, like that seen around the Great Lakes of North America. The lake effect happens when already moist air picks up more moisture as it crosses over a warm body of water, then rains or snows it out quickly upon reaching the shore.
In all, a whopping 62 square miles of land are expected to see weather effects from the dam, he said. That’s more than ten times the area originally predicted, he said.
In a way, he said, Three Gorges is a great laboratory for studying how well local climate changes caused by very local land-use changes can be detected and distinguished from larger-scale global climate change.
Photo taken on July 1, 2009 shows the Three Gorges Dam opening two deep-holes and a trash way hole for sluicing the mounting flood water, in Yichang, central China's Hubei Province. The Three Gorges Reservoir has high influx of flooded water along with the arrival of Yangtze River's main flood season with recent days' persistent rainfalls.(Xinhua/Wen Zhenxiao)
In February 2009, a growing number of American and Chinese scientists suggested that the calamity was triggered by a four-year-old reservoir built close to the earthquake's geological fault line.
A Columbia University scientist who studied the quake has said that it may have been triggered by the weight of 320 million tons of water in the Zipingpu Reservoir less than a mile from a well-known major fault.
His conclusions, presented to the American Geophysical Union in December, coincide with a new finding by Chinese geophysicists that the dam caused significant seismic changes before the earthquake.
The devastating earthquake that killed 80,000 people in China’s Sichuan Province last May may have been triggered by a recently built hydropower dam that lies only three miles from the quake’s epicenter, some researchers are arguing. The several hundred million tons of water piled behind the Zipingpu Dam put just the wrong stresses on the adjacent Beichuan fault, [says] geophysical hazards researcher Christian Klose [Science, subscription required].
Fan Xiao, the chief engineer of the Sichuan Geology and Mineral Bureau in Chengdu, said it was “very likely” that the construction and filling of the reservoir in 2004 had led to the disaster. “There have been many cases in which a water reservoir has triggered an earthquake,” said Mr Fan. “This earthquake was very unusual for this area. There have been no seismic activities greater than a magnitude seven quake along this particular seismic belt before” [Telegraph].
Originally posted by Thebudweiserstuntman
A lot of info there - any chance of a summary?
Not got time to read all that, and particularly with ATS i'm less and less willing to spend time reading what usually turns out to be insane ramblings - not that I am suggesting what you have there is insane, a summary would let me know if your argument is relevant / interesting enough to warrant me spending time going through all that info!!
Originally posted by geo1066
reply to post by DataWraith
How true 'DataWraith'!
Okay, I'll give the 'Cliff notes' on it-
It's a really big dam in China.
It holds alot of water.
It's over major fault lines.
It has unrepairable cracks in it.
It's causing local climate changes.
It's collecting all the sewage from upstream.
It's collecting mega tons of sediment.
And the Chinese engineers say they screwed up!
I still think the way 'Questionall' put it was better though.
Update, Dec. 29, 2004: Explainer spoke too quickly; you may still need to adjust your watch early next millennium. According to Richard Gross of NASA's Jet Propulsion Laboratory, it's possible that the Earth's rotation did indeed speed up slightly as a large chunk of the crust fell toward the planet's core, just as a spinning figure skater speeds up when she pulls in her arms.
"I used a model of the elastic properties of the Earth along with the seismically determined source properties of the earthquake to compute the change in the distribution of the Earth's mass caused by the earthquake, and hence its effect on the Earth's rotation, including the change in the length of the day and in the Earth's wobble," Gross told Explainer in an e-mail. "This calculation predicts that the earthquake should have shortened the length of the day by about 2.7 microseconds, and caused the Earth to wobble by about another 1 inch."
Stuart Sipkin, a research geophysicist who has been studying the quake at the USGS's National Earthquake Information Center, doesn't dispute the calculation but urges caution until the model's projection can be confirmed with observed data. Unfortunately, that's not possible; according to Gross, current length-of-day measurement techniques are accurate to only 20 microseconds.