abplive.in
Nilanjan Ghosh
December 4, 2015
A prime point of contention with China-India strategic relation is related to the popular hypothesis floating around with China’s plan of northward rerouting of the Brahmaputra waters from the Tibetan borders through constructions of dams. Foremost strategic thinkers of India have expressed that this Chinese design of water diversion is “most dangerous”. It is a fact that China has been damming most international rivers flowing out of Tibet. It is also a fact that most of these Himalayan river ecosystems are vulnerable to the vagaries of global warming and climate change, though the knowledge on the impacts is insufficient to arrive on the intensity of the effects. The Indian concern was more from the perspective of the Chinese designs of water diversion.
This hypothesis of the ill-effects of the Brahmaputra diversion and its egregious impacts on North-East India (or “Brahma hypothesis” henceforth) has gripped media and policy circles like wildfire. The common people in India have started believing that China has woven yet another nefarious conspiracy against India, and the diversion of the Brahmaputra (or Yarlung-Tsangpo in Tibet) from the Tibetan borders towards the north will dry up the course of the Brahmaputra and will be detrimental for the development of the Indian north-eastern states.
The most recent Chinese intervention on the Brahmaputra in the Tibetan border has already been operationalised. This is with the construction of the Zangmu Dam, which is a gravity dam on the Brahmaputra River 9 km northwest of Gyaca in Tibet. By 2016, five other dams would also be completed, making a chain of hydro projects on the river intended to exploit the waters for hydropower generation. The station, believed to be positioned at the world’s highest altitude, is expected to produce 2.5 billion kilowatt-hours of electricity per year.
However, the fact remains that the problem has not yet arisen, despite the operationalisation of the dam, and it is less likely to arise. The first reason for that is that this entire project is based on the “run-of-the-river” technology. Therefore, rather than water diversion the need is more with using the altitude, velocity, and volume of the flow. A diversion could have worked on the contrary. Irrigation definitely was not in Chinese minds when they conceptualized this operation.
More importantly, this diversion would have increased the costs to China manifold. China has reported plans of South-North water transfers through river interlinking within the Chinese boundary, and that has nothing to do with India. The engineering design of such a plan is not in public domain, and hence cannot be commented on. But, the fact remains that China has taken up the cause of the ecosystem much more than what India has done, and have incorporated this effectively in their engineering designs. As reported, the Chinese engineers are deeply studying the sediment science and fluvial geomorphology before any form of intervention over their waters. Therefore, they have a better understanding of sediment flows and its importance.
The second point of contention against this “Brahma hypothesis” is whether any form of diversion (if at all) can, at all, cause egregious impacts to North-East India. Though emerging from the Himalayas, Brahmaputra is fed by snow and monsoon rains.
A large component of the Brahmaputra stream-flow emerges within the Indian boundary, and is being fed by the Indian tributaries. A very conservative estimate will suggest that around 85% of the total stream-flow emerges within the Indian boundary. There is a huge difference in stream-flow between Bahadurabad measuring station and the Zangmu Dam, and the annual hydrographs suggest that the former has around 5 times more flow than the latter. In fact, as suggested in one of the most comprehensive assessments of the Brahmaputra river, The Brahmaputra Basin Water Resources, the peak flow in Guwahati, Assam is to the tune of 60 cumecs, almost 9-10 times of that of Tsela Dzong, measuring station closest to Zangmu, where it is barely 6-7 cumecs. Therefore, even if there is any diversion in the Tibetan region, it is less likely that there will be substantial impact on North-East India.
However, the general perception based on linear algebraic thinking is somewhat different. I came across one news article that inferred that because out of the Brahmaputra’s total length of 2,880 km, 1,625 km is in Tibet (or China), 918 km is in India, and 337 km is in Bangladesh, the Tibetan territory has maximum flow. Therefore, the general belief is that a diversion can be problematic for India and Bangladesh. But hydrograph readings, as stated in the last paragraph, suggest something completely different. This is because flow of a river system is not a linear function of the length of the river.
Therefore, my contention is that a myth has been created through the “Brahma” hypothesis. This is because the working hypothesis is less scientifically informed, and moved more by nationalistic emotions and very linear logic, rather than scientific knowledge. But, the domain of hydropolitics is not so linear. Informed science, by all means, has to inform policy.
(The writer is Senior Fellow, Observer Research Foundation, Kolkata and Senior Economic Advisor at WWF-India. Email: nilanjan.ghosh@gmail.com)
