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Saving south Asia’s water

Geologist, explorer and independent scientist Yang Yong tells Beth Walker what he has learned about sharing water resources from over 20 years spent rafting China’s rivers.

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Yang Yong has spent over 20 years rafting on China’s rivers, exploring the network that drains the Tibetan Plateau. Yang was one of first rafters to navigate the perilous upper reaches of the Yangtze and the Yarlung Zangbo to investigate the geological and hydrological conditions of the river basin. He has observed the impacts of climate change and development, and seen the snow and ice of the world’s third pole disappear before his eyes. Speaking to Beth Walker on the sidelines of a third pole media workshop to discuss the impacts of climate change on the Yarlung Zangbo in Kathmandu this month, he discussed his work and the future of Asia’s rivers.

Beth Walker: Can you explain the importance of the Yarlung Zangbo River [known as the Brahmaputra in India]?

Yang Yong: The Yarlung Zangbo is an important source of water for China, India and Bangladesh. The river provides important economic benefits and supports livelihoods, especially in Bangladesh where the river runs through densely populated areas. Where the river begins in Tibet, it represents the cradle of Tibetan culture. The river is sacred for local people who have built temples and carry out religious rituals along its banks. The source of the river is found on the slopes of Mount Kailas (the western section of the Himalayas), where Buddhist, Hindu and Bon gods are believed to reside.

BW: Why did you become interested in rivers? And why particularly the Yarlung Zangbo?

YY: I grew up in a small village up on the cliffs by the valley of Jinsha River (upper reaches of the Yangtze River), in Jinyang county in Sichuan, southwest China. When I was young, my mother told me not to play by the river, otherwise Shui Long Wang the river dragon that lived below would pull me into the river. Back then the river below in the deep valley remained a mystery to me. It marked the edge of my childhood world and drew me in. When I grew older I decided that I had to explore the river by rafting. At university in Chongqing [western China] I studied geology at the China Mining Industry University and this formed the foundation of my later research.

I began to explore all the rivers of the Tibetan Plateau in the 1980s. There had been very little research done and no data available for many parts of the rivers. In 1986, I rafted the Yangtze from source to mouth, through canyons that had never been passed through to collect hydrological and geological data, and to record information about the river valley and the landscape along it. Fifty-five people took part in the expedition and 10 people died when our boats capsized. Since then I have walked along and intensely examined the most important sections of the river.

I discovered there was less and less water on the upper tributaries of the Yangtze and intensifying soil erosion and geological disasters after the river and its tributaries have been developed since the 1980s. So I went in search of other water sources on the Tibetan Plateau. In 1998 I led a similar research adventure along the Yarlung Zangbo – the first descent of the river from the source to the Great Bend before the river flows into India. I wanted to understand how this river could pass through such a deep gorge, over 5,000 metres deep, the deepest gorge in the world. We travelled 1,800 metres by raft and 400 kilometres by foot over a period of over four months. Since 1998 and 2010, I have been back five times to research the river.

BW: What impacts of climate change have you observed over the 20 years you have carried out your research?

YY: Our 1998 trip along the Yarlung Zangbo took place just after major floods ravaged the Yarlung Zangbo River, the middle and lower streams of the Yangtze, the Song Hua and Nen River in northeast China. I believe these floods were a sign of climate change. I have seen an accelerated melting of glaciers on the Tibetan plateau, on average between 200 and 500 metres for the majority glaciers over 20 years.

Desertification of grassland has spread, in places across patches over 100 kilometres long and 10 kilometres wide in the upper stream of Yarlung Zangbo. In some places the different sand dunes patches have connected. This has been caused by climate change and convincingly as well by human activity. In Zhongba county in the Shigatse region of western Tibet, people have had to resettle two or three times because of the accelerating desertification process. If desertification continues, it will decrease the flow of water downstream and eventually this region could become a second Taklamakan desert. There have also been an increasing number of mudslides caused by glacier avalanches, and this increases the chance of geological disasters.

BW: How should the three countries through which the Yarlung Zangbo flows tackle these environmental issues?

YY: The three countries – China, India, and Bangladesh – should cooperate to utilise its water resources and design a comprehensive river basin plan. This must include measures to predict and control hazards, such as floods, landslides and other geological disasters, the impact of hydroelectric projects, changing river flow, and procedures to address and respect each country’s water needs and rights. NGOs and media and scientists all play an important role in encouraging this collaboration.

BW: There has been a Chinese proposal to build the biggest dam in world at the great bend of the Yarlung Zangbo. What will the environmental impacts be?

YY: Since 2006, the government has planned to build nine dams in succession, with a capacity of over 40,000 megawatts at the 400-kilometre long “great bend” of the Yarlung Zangbo before the river flows into India. The basic technical idea is to divert the water directly before the bend, and the water will merge back with the mainstream afterwards. The dam will consist of nine tiers. At this point the water flow drops down a height of over 2,000 metres and therefore you don’t need to build a big reservoir, or inundate a lot of land, to generate huge amounts of electricity.

Theoretically, the dam will not impact the water flow downstream. But the construction may cause environmental problems and geological risks that need more attention. The dam site lies within an immensely deep gorge that has rich biodiversity and complicated geological conditions. This makes construction and getting machinery to the site very challenging. The biggest concern is the geological risks. The project is at the convergence point of three gigantic mountain ranges and several very big rivers.  Given the risk of earthquakes and mudslides, more research is needed before plans go ahead. 

Construction of the Zangmu dam on the upper Yarlung Zangbo has already begun and is one of five relatively smaller dams planned in a much smaller gorge. But it only controls water flow of its upper stream, and this area is not so geologically sensitive.

BW: India and Bangladesh are very concerned that China’s hydro dams and water projects will reduce downstream water flow. Are these concerns founded?

YY: There are two issues here. Firstly, India and Bangladesh’s concerns over reduced water flow due to Chinese projects are not based on scientific evidence. The water flow of the Yarlung Zangbo at the point where the dam is under planning counts for only 50% of the total outflow of the river at the other side of the bend before the river enters India, and roughly eight times greater once it reaches the Bay of Bengal. Even if China went ahead with diversion plans on the river [the Chinese Water Ministry announced it will not in October], water flow downstream would not be affected. Myths about this have been fuelled by media hype.

Secondly, Chinese dams on the upper stream section could in fact provide benefits to Bangladesh by controlling the water flow and floods in summer if these dams store enough water. In any case, the planned dam at the Great Bend at Motuo will not happen for at least 10 years. It is still not clear how the power will be used. If it just goes to Tibet, which is not linked onto the electricity grid at present, the project will not be economically viable. More likely, electricity will be used to meet demand in south Asia. The three countries need to communicate with each other better and to collaborate particularly on issues of flood control.

BW: What are the biggest threats facing [dam projects] on the Yarlung Zangbo River basin?

YY: The biggest concern is the geological threats and impacts on biodiversity, in both China and India [where the authorities plan to build 70 large dams in an earthquake-prone region]. If an earthquake occurs, dams will burst and cause destructive floods downstream, such as the massive flood on the Yigong River [a tributary of the Yarlung Zangbo], when a barrier lake breached, causing deaths and destruction in southern Tibet and India in 2000. There needs to more research carried out to increase the understanding of earthquake tendency as well as geological risks, stronger regulation of dam construction and trans-national coordination. All countries involved should work closely and strive to lay a good scientific foundation before any significant developments rush in.

Beth Walker is a researcher at chinadialogue’s project the third pole.

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