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Showing posts with label Dam. Show all posts
Showing posts with label Dam. Show all posts

The Three Gorges Dam ...Incredible Engineering...!!!

Posted by Vikramsinh at Saturday, December 5, 2009

“Any sufficiently advanced technology is indistinguishable from magic.”

Man is always craving for more advanced and comfortable life. His never ending quest to improve and excel in all directions and aspects of life brings today’s extremely transformed, complex and wonderful world.

Here is the perfect example of historic engineering feat, Three Gorges Dam. Its stats will amaze you; its view will mesmerize you and changes in the environment brought by Dam will compel you to think about our material greed.

There are around 86000 dams overall on the world and around 46000 belongs to China. Energy hungry China always crave for more and more power. Chinese coal mines already taking many lives, but Chinese leaders are more concern about prosperity of nation than people's lives.

Three Gorges Dam is the world's largest electricity-generating plant of any kind. Constructed on Yangtze river. The greatest of the projects took 17 years. Started in 1994, the dam was expected to be fully operational in 2009, but due to additional projects such as the underground power plant with six additional generators, and due to the complexity of the ship lift, the dam is not expected to become fully operational until about 2011.
Dam costs total of US$40 billion. It causes the displacement of over 1.2 million people from the 60,000hectares of and which will gradually be flooded by the resulting 640-kilometre (397-mile) long reservoir. Here is the Official site.

Statistics shows Comprehensive Project Construction Scale.

The construction includes the following work:

-- Removing 102.59 million cubic meters of stone and earth and filling with 29.33 million cubic meters of stone and earthwork;
-- Mixing and pouring 27.15 million cubic meters of cement;
-- Erecting 281,000 tons of metal structure. It used 463,000 tonnes of steel, enough to build 63 Eiffel Towers;
-- Making and erecting 354,000 tons of reinforcing bars;
-- Building 231,000 square meters of leak-proof concrete walls;
-- Installing 32 power generators with a 700 MW capacity each which results in combined capacity of 18.2 million kilowatts;
-- Creating Dam of height 101 m from river level and 185 m from see level, width 115 m, length 2335 m


The project produces hydroelectricity, apart from that provides greater flood control and river navigation capacity. Up to September 2009 the dam has generated 348.4 TWh of electricity, covering more than one third of its project cost. Project management call it as social and economic success, a breakthrough in the design of large turbines, and a move toward the reduction of greenhouse gas emissions. The technological breakthrough is really stupefying. Here is a video animation of the generators.

There are environmental advantages such as reduction in air pollution and green house gas emission by generating electricity from hydropower instead of coal and by providing pollution free navigation. Waste water management. Afforastration. Flood control and drought relief.

But it has darker side also
Threat to Ecology - The dam will significantly decrease the river's flushing capacity, and the pollution ratings will increase.
Erosion and 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.
Affected aesthetic values - Cultural and historical relics are being moved to higher ground as they are discovered, but the flooding will undoubtedly cover some undiscovered relics.
Security - Threat from terrorists.
Earthquakes - There is also the potential for earthquake-induced peak ground acceleration to overcome the strength of the upstream face of the dam which, coupled with the immense weight of the reservoir water, could cause breaching.

I don't know what to say..Whether it is good or bad? Better you decide and tell me ....