Thursday, March 23, 2017

Tibet’s Waters for Xinjiang: Another Diversion of the Brahmaputra?

Picture accompanying the Chinese article
I often mentioned on this blog, the different 'diversion' schemes, whether of the Yarlung Tsangpo (Brahmaputra) or the Indus River.
Now, a new one has come to light.
According to an official Chinese website, during the 'Two Sessions', the China Railway Tunnel Group Co Ltd (CRTG), the largest specialized company in the field of underground works in China, which integrates design, construction, scientific research and manufacture, proposed to divert the Yarlung Tsanpo (Brahmaputra) from Tibet to Xinjiang.
CRTG is itself a subsidiary of the China Railway Group Ltd, with has 14 wholly-owned subsidiaries, 3 holding subsidiaries, 2 share holding subsidiaries and 8 branch companies.
The company likes to think big (money).
Whether it could trigger a conflict with India is not its concern.

The New Scheme
During the Second Session of the Twelfth National People's Congress (NPC), CRTG’s Deputy Chief Engineer Wang Mengshu submitted a project for the first phase of mega ‘a water diversion’ scheme.
Wang Mengshu stated that the water transfer project could not only help the ecological environment in the project area, but also greatly improve the social and economic development of the region, i.e. Xinjiang.
It would also improve the transportation, energy, communications and other infrastructure conditions in Southern Xinjiang, on a desert area covering 80 million square kilometers which could be transformed into an oasis.
It would later help ‘transferring’ of a large number of people to this strategic area of Western China.
In a long-term, it would have a great significance for the development of the region.
The ‘proposal’ has been worked out with the Hydraulics and Mountain River Development Department of the Sichuan University. Key national research laboratories are ready to provide further support.
Wang Mengshu introduced the first phase of the project to divert some 10 billion to 15 billion m3 from the Yarlung Zangbo River (Brahmaputra) to Southern Xinjiang.
The main feature of the project would be that the transfer of flood waters would not require a hydropower station power generation required as the waters would flow downstream and the ecological environment of the basin would not be significantly affected.

The first hub: four features
The first hub would not used 'water diversion technology’ with a dam.
Gravity through a tunnel would be complemented by smart water management for the distribution system.
In his introduction, Wang Mengshu said that in the first phase of the project, there will four major technical features.
One, the first part will not use a dam for the diversion.
It will conform to natural and sustainable laws.
Second, the traditional Dujiangyan watershed, sand and diversion control technology and water flow control technology will be utilised.
What is a Dujiangyan irrigation system?
According to Wikipedia, it was originally constructed around 256 BC by the State of Qin as a water conservation and flood control scheme. The system's infrastructure is on the Min River (Minjiang) in Sichuan.
The area is situated in the western portion of the Chengdu flat lands at the confluence between the Sichuan basin and the Qinghai-Tibet plateau. Originally the Minjiang rushed down from the Min Mountains, but slowed abruptly after reaching the Chengdu Plains, causing the watercourse to fill up with silt, making the surrounding area extremely prone to flooding. Li Bing, then governor of Shu for the state of Qin, took care of the construction of the Dujiangyan, which harnessed the river using a new method of channeling and dividing the water rather than simply following the old way of dam building. It is still in use today to irrigate over 5,300 square kilometers of land in the same area.
In the 'diversion' scheme, the principles will be to utilize ‘curved circulation’ to achieve secondary water flow and sedimentation, the use of ‘settling sedimentation’, and finally use of a shaft to control the water, according to the principle of using floods waters.
It could work even during the dry season, as well as meet the downstream ecological requirements while helping reduce the downstream floods.
The third feature the water supply will be the use of gravity through flow tunnel technology, it will avoid evaporation along the way.
All other technical issues will make the project safe and reliable.
Fourth and finally, the pressure-flow will be self-regulated by the shaft technology which can be used to divide the whole water delivery system into several relatively independent subunits.
It can reduce the ‘water hammer pressure’ of the whole water supply system and avoid the full range of diffusion and propagation of hydraulic oscillation.
And also it will reduce the 'vibration' of the water flow system and tackle other issues; it will be easy to control and will fully transfer the flood waters.
The structure is also relatively simple, according to Meng, though not easy to understand for the lay man.
Wang Mengshu said that this water transfer technology is feasible, the ecological impact is minimal; it has a low operating and maintenance costs.
With the use of tunnels for the water supply, water evaporation loss is minimal and water security is fully protected. The principle of taking away flood waters, will avoid the outflow of surplus water downstream and even will reduce the pressure on the river flood control.
Wang Mengshu suggested carrying a demonstration of the water diversion project. On this basis, the implementation of the first phase of the project is feasible, he said.
The translation of the article might not be perfect but it gives an idea of the concept of the project.

What about India?
No doubt that the ‘tunnel lobby’ is as powerful as the ‘dam lobby’ in the Middle Kingdom.
Like the other projects reported in this blog earlier, it is a dream of megalomaniac engineers, who forget that the Yarlung Tsangpo (the Siang in Arunachal Pradesh and later the Brahmaputra and the Jamuna in Bangladesh) is not the sole property of the the People's Republic of China.
India and Bangladesh have a say as far as the utilisation of its waters is concerned.
It is probably one of these projects to remind India that China, by controlling Tibet, also control the Tibetan rivers and can create a lot of trouble for the lower riparian States.
Can it go further than the drawing board?
It is doubtful.

Some previous posts

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