The dam’s upstream face has 100 cracks, some along its full height.
Chinese government had ordered the reservoir to be filled up, and now the cracks are largely hidden underwater. Fan Xiao, a senior engineer with the state geological agency in Sichuan, was previously quoted as alleging that inferior materials had found their way into the dam’s construction. Later asked by a U.s.-based newspaper to confirm that statement, he said he’d been instructed “not to take foreign media interviews.” But the structural integrity isn’t the only problem.
Geologists have discovered even more troubling risk factors that seem to have been entirely ignored by the government and its engineers when the Three Gorges Dam was designed. China has almost 88,000 dams in all and more large dams than any other country in the world. Recent studies have shown that many of them have been constructed in areas of tectonic instability. In fact, when a magnitude 5.1 earthquake happened near the Three Gorges Dam in 2013, there was ample speculation that the cause was related to the giant dam. There had been only low seismic activity in the region before the dam was built, but it subsequently rose to seven or eight times the previous level. And though the dam escaped damage at the time, researchers were concerned that the risk remained. “The same fault could store enough energy to generate an earthquake that is strong enough to cause damage to the Three Gorges Dam,” says Lupei Zhu, a professor of geophysics at Saint Louis University. Scientists from his department had been conducting a seismic recording experiment in the region when the 2013 earthquake struck. “The quake
occurred almost directly beneath one of our seismic stations,” recalls Zhu. “That gave us a unique opportunity to pinpoint the location of the shock.” He found that the quake had taken place along a previously unidentified fault connected to the reservoir. There is speculation that the sheer weight of the water in the reservoir triggered the earthquake.
A similar event occurred in 2008 near the city of Dujiangyan in Sichuan Province. Called the Great Wenchuan Earthquake, it was utterly devastating: It flattened four-fifths of the structures in the area, destroying whole villages and towns; the quake killed almost 90,000 people and injured another 375,000. An international study led by geologist Fan Xiao concluded that the magnitude 8 quake was triggered by the weight and pore pressure of the Zipingpu Reservoir. This time the earthquake caused damage to the dam there. The reservoir, which holds more than 350 million tons of water, had to be drained out for repair. That raised serious questions about the quality of Chinese dams in general. “Construction of most dam projects in China has not been carried out in line with the Environmental Impact Assessment Law,” explains Li Dun, a social policy professor at Tsinghua University in Beijing. “The improper construction methods caused great negative impact to the environment and the lives of local residents.”
A statement issued by the Chinese State Council in 2011 and approved by then–prime Minister Wen Jiabao admitted that the Three Gorges Dam had pressing human, ecological, and geological issues. “While the project provides huge benefits, some urgent problems must be resolved regarding ecological protection and geological disaster prevention,” the statement read. Years after the completion of the dam, there’s evidence the project is, indeed, altering ecosystems and causing erosion of slopes as well as landslides in addition to more serious tectonic problems. The reservoir sits atop two major faults, the Jiuwanxi and the Zigui-badong, and geologist Fan Xiao warns the changing water level puts strain on them: “When you alter a fault line’s mechanical state,” he says, “it can cause seismic activity to intensify and induce earthquakes.” American geologists compare the situation to that of California’s Oroville Dam, first filled in 1968. Seven years later the water level was lowered for maintenance, and the region began experiencing a very unusual series of earthquakes. Seismologists from the U.S. Geological Survey concluded there was a strong link between the quakes and the reservoir’s changing level. Rising water levels can cause other problems as well. Filling up the Three Gorges Reservoir widened the channels of its tributaries where they previously flowed into the Yangtze, sometimes doubling their width. In one well-publicized case, that caused 700 million cubic feet of rock to slide into the Qinggan River, generating 65-foot waves that killed 14 people. In yet another incident, the ground gave way near another tributary, and 108,000 cubic feet of rock and earth poured onto a road and buried a bus, claiming 30 lives.
Many of these attendant problems were unforeseen, and in any case the advantages appeared clear enough. To support building the Three Gorges Dam the government had advanced several arguments. According to Dai Qing, a journalist and environmental campaigner, “They said this project would produce power, provide flood control, improve navigation, and also benefit local citizens.” Although she readily concedes that Three Gorges is “the largest dam project on Earth, with the longest reservoir, the highest ship-lift, and the largest capacity for power generation,” she points to the high costs of resettlement, treatment of polluted water, and environmental protection, and she notes that China’s list of shortcomings is otherwise long as well. “We can also claim to have the most polluted air, the most frequent mine catastrophes and deaths, the most expensive administrative costs, and the largest gap between poor and rich with the highest percentage of an illiterate population.” Dai places the blame squarely on the shoulders of the system of government: “China’s undemocratic political system as well as its economic environment of crony capitalism have, together, paved the way for the Three Gorges Project.”
The dangers of flooding and huge landslides along with the effects of errors in construction, a tectonically unstable location, as well as the everpresent danger of terror attacks adds up to an incalculable risk posed by the ticking time bomb that is the Three Gorges Dam. Western geologists are largely united in the viewpoint that a hazard of such epic dimensions would be shut down in the West. Dai agrees: “The West has stopped building such dams. Why did China build such a big one on a river that is over-exploited, over-populated, and already intensely damaged? They destroyed the river.”
At 455 feet high and with a weight of nearly 6 million tons, the 4,500-year-old Great Pyramid of Giza in Egypt (on the right in the photo) is the last wonder of the ancient world to remain intact today and a true masterpiece of architecture. For centuries researchers and scholars wondered how it was possible for the ancient Egyptians to erect such monuments without cranes and modern machines, and now a recent find finally provides a substantial clue. During excavations taking place north of Luxor, an international team of archaeologists uncovered a giant stone ramp and several post holes, which were evidently crucial for moving stone blocks from a quarry. The experts are certain: With the help of the system that was anchored there, even the heaviest loads could be lifted up the ramp through the use of cables. In order to compensate for
height differences in the terrain, the huge blocks would’ve been loaded onto wooden slides and pulled to the construction site by way of several of these “loading ramps.” The find of the archaeologists, who include researchers from Egypt, France, and the UK, coincides with scenes from many ancient murals in which the construction of the desert monuments is depicted. The ramp dates back to the reign of Khufu, who ruled Egypt from 2589 to 2566 and for whom the tallest of the three pyramids of Giza was built. “This find gives us invaluable insight into the logistics and techniques required to build the Great Pyramid of Giza,” explains Roland Enmarch of the University of Liverpool. The construction process of the pyramids still contains its share of mysteries, with some speculating a system involving water was also used to float segments of the massive structures.