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World's largest hydropower project planned for Tibetan Plateau

The cascade of dams planned for the Yarlung Tsangpo river and its tributaries – including one three times the size of the Three Gorges Dam – threatens an already fragile environment

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Desertification has turned transformed swathes of the upper Yarlung Tsangpo into desert (Image by Yang Yong).

This is part of a special series of articles produced by our sister site thethirdpole.net on the future of the Yarlung Tsangpo river - one of the world's great transboundary rivers - which starts on the Tibetan Plateau before passing through India and Bangladesh.

Also read:
- It's time for a new era of cooperation on the Yarlung Tsangpo
- Why India and China should leave the Yarlung Tsangpo alone
- Yarlung Tsangpo river is a living ecosytem, not just a source of hydropower

The Tibetan Plateau, the world’s third pole, gives birth to many of Asia’s major rivers. As the key for maintaining the continent’s ecology, and one of the world’s most important ecosystems in its own right, it is of huge strategic significance.

The Yarlung Tsangpo (known as the Brahamputra in India), which runs alongside the majesty of the Himalayas, is the world’s highest river. It runs west to east along the rift created by the impact of the Eurasian Plate, cutting through the Tibetan Plateau until it meets the point where the Himalayas, the Nyenchen Tanglha and Hengduan mountains join. Here it forces its way between the Gyala Peri and Namcha Barwa peaks to form the world’s deepest gorge, then makes its way to South Asia where it joins the Ganga and flows to the Indian Ocean.

The Yarlung Tsangpo rises at a high altitude, in a geologically complex area. The river’s powerful flow, long course and large drop in altitude give it great potential for hydropower development. But the scale of dam building planned by China and India could have disastrous ecological consequences.

China's plans date back to the early 1990s, when it carried out a series of hydropower development surveys of the river, with the Yarlung Tsangpo Gorge the focus of interest.

In the late 20th century, this gorge was recognised as the world’s deepest. In the 400 kilometres from the top of the gorge, the river twists around the mountain of Namcha Barwa (known as the Great Bend) and loses more than 2,000 metres in altitude, forming several waterfalls and giving up huge energy potential as it goes. Hydropower experts say a tunnel that cuts the river’s natural loop could carry 2,000 cubic metres of water a second, with a drop in altitude of 2,800 metres – enough to power a 50-gigawatt hydropower station that could provide 300 billion kilowatt hours of electricity a year. It would be the largest hydropower project in human history - about three times the size of the Three Gorges Dam.

The world's largest dam

Eleven hydropower stations are planned on the river, three along the middle reaches from Sangri to Gyaca, and nine on the gorge up to the Great Bend, with total generating capacity of 60 gigawatts.

Work started on the Zangmu Dam – one of the three planned on the Sangri-Gyaca section – in 2010 and this is expected to be generating electricity this year. There are also plans for about 65 gigawatts of hydropower development on the major tributaries of the Yarlung Tsangpo.

India has also been planning hydropower development along the Yarlung Tsangpo and its tributaries on a huge scale; public and private companies have proposed 168 massive dams, to produce 57 gigawatts of hydropower in the country’s north-east.

Proposed dams in north-east India (Image by International Rivers)

Floods, landslides and extinction

The Yarlung Tsangpo Gorge is a young and still active geological formation, any interference could have disastrous knock-on effects, from which the ecosystem may not be able to recover.  

There are powerful geological stresses here, and seismic activity and landslides are common. The gorge is still taking shape, and I have found more than 100 active landslips or mudslides which any future earthquakes could worsen.

In the early 1950s, an earthquake of magnitude 8 on the Richter scale caused many secondary landslides, which resulted in sustained flooding downstream. In April 2000, I personally witnessed a huge landslide at Yi’ong, which created a four billion cubic metre barrier lake. Sixty days later the barrier failed. The resulting floods affected millions of people and paralysed transportation. Natural disasters of this type are common here.

We still don't know what the long-term impact of climate change will be on the Tibetan Plateau, but the glaciers and snowlines of the Himalayas are retreating, depriving the rivers of a source of water. If this continues, the plateau’s waterways will be cut off, or even dry up and the land will become a desert.


The Maquanhe glacier at the source of the Yarlung Tsangpo River (Photo by Yang Yong)

Today, the ecosystem of the gorge region is already in decline. The primary forests made up of tall trees are now over-mature and swathes of forest over 2,500 metres in altitude are dying. Secondary growth is mono-cultural – the forests are failing to regenerate. Meanwhile, the Monpa and Luopa people who live deep in the gorge continue slash-and-burn methods of farming – the forests on many steep slopes have been torched to provide farmland, resulting in the rapid spread of soil erosion and landslides.

Much of the area’s wildlife – it is one of the most biodiverse regions of the world - is also facing extinction. The ecosystem of the gorge and surrounding areas have become fragmented, meaning animals have smaller areas in which to roam. This leads to imbalances in the food chain, while the mono-cultural secondary forests prevent populations growing and surviving.

The importance of the Tibetan Plateau’s environment to the health of the Yarlung Tsangpo and other rivers should not be ignored. Its worsening environment is a major factor in the degradation of the ecologies of the Yarlung Tsangpo and other rivers; interference from human development and hydropower projects will only add insult to injury. 

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Default avatar
匿名 | Anonymous

对于大坝问题的评论

水坝的高度应限制在六百尺内,因为在遇到地震或战争时,水坝过高的话,坍塌后倾泻的存水会对周围地区和基础设施造成灾难性破坏,并引发洪涝和死伤。

另外,增加水道的交通,例如多设轮船水道及水闸,有助减低堤坝附近地区对陆上交通的依赖,减少汽车二氧化碳排放,大大减少温室气体的产生,保护西藏的生态环境及铁路。同时,也会降低对石油、天然气等的依赖,让这些能源公司不会过于垄断,剥削农民。

comments about dams

I would limit the heights of dams to 600 feet during dam building because if there too high in height and get severely damaged during an eathquake or war they could cause a tremendous downrush of water and ruin or destroy down river dams and other government infrastructure built in previous years and might cause catastophic flooding and death.

I would make sure shipping locks for shipping to pass through are built. If there not large shipping will only be done by trucks and exhaust gas polution more asfault pavment which radiates heat and creates greenhous gases and can disrupt the ecology and damage the railroad in tibet. It will also create increases in fuel costs draining peasants pockebooks in the capitolist countries too. Also will allow oil companies to dictate there will on the peasants.

Default avatar
匿名 | Anonymous

Dams in western China

I'm an American geologist and professional river guide who has rafted or kayaked over 1000 miles of rivers in western China since 1994, often with Chinese geologists, including Yang Yong. I manage a website describing the history of exploration and the geology of the Yangtze, Yellow, Mekong, Salween, Yarlung Tsangpo and Indus river canyons from their sources on the Tibetan Plateau to their lower elevations in Qinghai, Sichuan and Yunnan (www.shangri-la-river-expeditions.com). This is a highly seismic area - among the most seismic on earth. I authored a report on large dams and seismic risk in 2012 that was published in both English and Chinese (http://probeinternational.org/library/wp-content/uploads/2012/08/JohnJacksonreport-July24.pdf) that describes the 70 large dams already built and another 70 under construction or planned. Yang Yong, Fan Xiao (another Chinese geologist) and many foreign geologists believe the Wenchuan earthquake that killed about 80,000 people was caused by operations at the Xipingpu Dam on the Min River northwest of Chengdu. Building 140 large dams on the rivers of western China will eventually result in very large earthquakes and maybe dam collapses.

Default avatar
匿名 | Anonymous

Save Planet

You are responsible country in this planet. So save Tibet region - the roof of the world then your generation will survive forever.

Default avatar
匿名 | Anonymous

Hydro is good.

Building hydropower promotes clean air which slows global warming thus it saves Himalayan glaciers.