highest river in the world
The Yarlung Tsangpo runs through the heartland of Tibet from west to east. It is often referred to in its short form, the Tsangpo, and is also known as: Yarlung Zangbo Jiang (Chinese); Brahmaputra (Indian—but referring to the river within India); Jamuna (Bangladesh).
Zangmu Dam on the mid-reaches of the Tsangpo is under construction. Located in a gorge 140km southeast of Lhasa, at an altitude of 3,260 metres, Zangmu Dam is expected to generate 540MW of electricity. Its height will be 116 metres and length 390 metres. Zangmu is the first dam in a series of five planned for the same region, in Shannan Prefecture (Lhoka). The five dams are Zangmu, Gyatsa, Zhongda, Jiexu and Langzhen. Construction is under way on 360MW Gyatsa (Jiacha) Dam and on 510MW Jiexu Dam.
THE GREAT BEND OF THE TSANGPO
Rising near sacred Mount Kailash in far-west Tibet, the Yarlung Tsangpo runs 2,900 km all the way across Tibet, and performs a neat trick in eastern Tibet—it makes an abrupt hairpin turn and flows west into India, then south again to its mouth in Bangladesh. This abrupt turn has been christened the Great Bend of the Tsangpo.
On its journey to the eastern side of Tibet, the Tsangpo soars into a 4,900-metre cleft between two towering snowcaps—Namche Barwa (elevation 7756m) and Gyala Pelri (7294m). In a distance of around 240km, the Tsangpo plummets some 2,700 metres through what is now known as the Yarlung Tsangpo Grand Canyon, the world's deepest gorge. With a depth reaching over 5,300m near the Tibet-India border, this gorge is more than twice the depth of Colorado's Grand Canyon.
Geographers had long speculated with such a precipitous drop, there had to be some huge waterfalls within the gorge, but because of its steep, forbidding walls, the site was impossible to get to. British explorer Frank Kingdon-Ward, undertaking a harrowing 11-month botanical expedition, discovered a waterfall of 12 metres in 1924. But it was not until 1998 that explorers Ian Baker and Ken Storm managed to break through to the most remote part of the gorge to discover a magnificent waterfall over 30 metres in height—the largest yet discovered in the Himalayas.
Although barely explored, the Great Bend is not seen as fantastic natural splendour by China's officials. China's engineers look upon the Tsangpo Gorges as the greatest potential for hydropower ever. In a plan first announced in 1996, Chinese engineers proposed building a monster dam here with potentially 38,000MW output. That output would be DOUBLE the output what is currently the biggest dam in the world, the Three Gorges Dam (output of around 18,000MW) on the mid-reaches of the Yangtse.
In May 2009, appearing on the Meltdown in Tibet website for the first time in the West was a Chinese-character map sourced from Hydro China in Beijing. Looking at this shocking map, you can hardly see the rivers for the dams (meaning the dam project balloons hovering over the rivers: to view this map, see Plateau Maps on this website). English annotations added on this website pinpointed plans for a massive dam at the Great Bend of the Tsangpo identified as Motuo, with a staggering capacity of 38,000MW—or roughly double the capacity of the Three Gorges Dam.
In May 2010, The Guardian (UK) interviewed Zhang Boting, the deputy general secretary of the China Society for Hydropower Engineering, who confirmed that research has been carried out on Motuo Dam, but the project is still at the drawing-board stage. Zhang Boting was enthusiastic about the massive dam, saying that it could generate energy equivalent to all the oil and gas in the South China Sea. It would appear that Motuo can be connected to a high-voltage grid that would enable power to be transferred from the mega-dam to mega-cities in eastern China. Zhang Boting told The Guardian:
“This dam could save 200 million tonnes of carbon each year. We should not waste the opportunity of the biggest carbon emission reduction project. For the sake of the entire world, all the water resources that can be developed should be developed.”
China's engineering spin-doctors are using arguments like this to make mega-dam-building sound eco-friendly, and to make them look like a viable method of countering the effects of climate change. However, Zhang Boting seems to have overlooked some key factors. For one thing, damming itself produces increases in greenhouse gases, particularly methane emissions from rotting vegetation in a dam reservoir. If China wants to be taken seriously about reducing its carbon emissions, then it should be looking at reducing its heavy dependence on coal-fired power plants. Currently, China has absolutely no intention of reducing the number of these CO2-spewing coal-fired power plants. In fact, the opposite is true: there are plans to considerably expand construction of coal-fired plants in the coming years.
Alarm bells have been sounded by environmental activists about the building of a dam on the gargantuan scale of Motuo. For one thing, the dam would be sited right in the region of Metok, considered sacred by Tibetans—and sited right in an earthquake-prone zone. The sacred valley of Metok has been inaccessible to outsiders for centuries due to its torrential rains washing away any attempt to build roads into the region. However, in 2010, there was an ominous turn of events: a tunnel over three kilometres long was rammed through by Chinese engineers as the key structure for a road linking Metok with the outside world. The outside world here means Chinese dam-builders and military.
Peter Bosshard of International Rivers, presents Motuo Dam in a quite different light:
“A large dam on the Tibetan plateau would amount to a major, irreversible experiment with geo-engineering. Blocking the Yarlung Tsangpo could devastate the fragile eco-system of the Tibetan plateau, and would withhold the river's sediments from the fertile floodplains of Assam in northeast India and Bangladesh.”
If Motuo sounds over-the-top-experimental, consider this: on the drawing board is an even bigger monster called Daduqia, also sited at the Great Bend, with a projected capacity of 42,000MW. The dam, like Motuo, would be a series of tunnels, pipes, reservoirs and turbines designed to harness what is widely considered to be the greatest hydropower potential in the world—at the Great Bend of the Tsangpo.
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