In 2009, we'll see the last phases of the construction of Three Gorges Dam- one of the most controversial dams in the world. Here's a little background into the Dam: The dam spans the Yangtze River in Sandouping, Yichang, Hubei, China. The total electric generating capacity of the dam will reach 22,500 megawatts,[1] at which point it will be the largest hydro-electric power station in the world by capacity. This is the biggest project that has been undertaken in China since the Great Wall and the Grand Canal. Several generators are yet to be installed; the dam is not expected to become fully operational until about 2011. As with many dams, there is a debate over costs and benefits. Although there are potential economic benefits such as flood control and hydroelectric power, there are also concerns about the relocation of over 1,500,000 people who have or will be displaced by the rising waters; siltation that could limit the dam's useful life; loss of numerous valuable archaeological and cultural sites; and significant adverse effects upon animal life.
During the last phases of the completion of the Dam, Yang Yi(the photographer below), who was born in a small town overlooking a tributary of the Yangtze River, will see his hometown being submerged under water.
To me this project depicts the epitome of China's rising to power in terms of weath and infrastructure, yet at the same time regards and respects for our environment has been greatly compromised it saddens me.
Uprooted
Environmental impact
Environmental issues with the dam include degraded water quality, detriments to wildlife, potential riverbank collapses, and potential silt related failing of coastal areas.
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 also contributed to the functional extinction of the Baiji, the Yangtze river dolphin. In addition, populations of the Yangtze sturgeon are guaranteed to be "negatively affected" by the 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
The 600 kilometre (375 mi) long reservoir has or will flood some 1,300 archaeological sites and alter the appearance of the Three Gorges as the water level rises over one hundred meters at various locations. 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 location, size or design. For example the hanging coffins site high in the Shen Nong Gorge is inherently part of the sheer cliffs themselves.
These historical sites contain remnants of the homeland of the Ba, an ancient people who settled in the region more than 3000 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 are submerged and others will soon be submerged.
Sedimentation
There are two hazards 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.
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 20,000 deaths. Critics believe that the Yangtze will add 530 million tons of silt into the reservoir on average per year; in time, this silt could accumulate behind the walls of the dam, clogging the turbines' entranceway. Further, the absence of silt down stream would have two dramatic effects:
- Some hydrologists think that this could make downstream riverbanks more vulnerable to flooding.
- 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 sediment the more vulnerable is this biggest of Chinese cities to inundation..."
Also, the weight of the dam and reservoir can cause induced seismicity, which occurred with the Katse Dam in Lesotho. The Benthic sediment build up is a cause of biological damage and reduction in aquatic biodiversity.[47]
National Security Concerns
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.” 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".
