DAMMING ACROSS THE BRAHMAPUTRA (YARLUNG TSANGPO) IN TIBET

Murchana Nath IX C

Modern English SchoolThe Brahmaputra is one of the most powerful river in the world. The river rises in Tamlumg Tso lake in Tibet east of Mansarovar Lake. It enters India in Arunachal Pradesh where it is called Dihang. It joins with Dibang, Lohit, and many other tributaries to form the Brahmaputra in Assam. The majestic river flows through Assam from east to west, creating the backbone of the state. After Assam, the river enters Bangladesh where it meets Ganges. It is called Jamuna there and finally flows into the Bay of Bengal after flowing a total length of 2900 km. The Brahmaputra is named as Yarlung Tsangpo in Tibet. When leaving the Tibetan Plateau, the Yarlung Tsangpo river flows in the world’s deepest canyon: the Yarlung Tsangpo Grand Canyon in Tibet. The river then flows through the south of Tibet Valley which is about 1200 km long and 300 km wide. This valley has a varied vegetation. The river has four major waterfalls. The largest one is the Zanglo Badong or the Hidden Falls. The other three waterfalls are Tsatan Muni, Chokor Tolang, and Rongdrak Waterfalls. The river has got several adventurous sports. The huge volume of the river water can be utilized to a great extent for the development of hydro-electric power. Due to its rising power shortages, and the increasing international pressure to reduce the pollution level, China has demanded the untapped reaches of the Yarlung Tsangpo. A major hydro-electric power project I Tibet was launched in November 2010. the most ambitious part of this project is a 38000 Mw mega dam at Metog. This mega river has the potential to generate output more than twice the capacity of the world’s largest power station. Chinese government argues that damming the river is a great alternative of burning coal in the country. But several studies have shown that dams affect the aquatics ecosystem including water quality, fish habitats, wetlands and livelihood of people relying on it. Dams also cause high evaporation, loss of water and are also a scientific cause of increase in greenhouse gases. The rotting organic matter that flows in the reservoir causes the increase of greenhouse gases. Construction of widespread dams on Yarlung Tsangpo has been controversial ecologically, socially and politically as it involves environmental impact of altering landscapes and ecosystems, and threatens the livelihood of several communities. The significant and unpredictable changes in the hydrology of the glacier-fed Yarlung Tsangpo could cause risk of dam failures and flood releases. Any event of flash flood in the upper reaches could have a dominant effect on the series of dams planned downstream of Tsangpo. Tsangpo also transports an exceptionally heavy load of eroded sediments and provides nutrients downstream on which river basin’s farmer and fish depend. Thus, the obstruction of sediment transport by the dam will not only impact the livelihood of the communities but also will cause erosion and landslides. Instead of perceiving Yarlung Tsangpo as a potential hydro power resource, serious consideration must be taken to address the long-term environmental and social impacts of such a ‘full-river’ development. The emission of greenhouse gases from the dams will ultimately destroy the warming trend in the Tibetan plateau. Thus, saving approximately 200 tonnes of carbon

each year might turn fruitful. The cumulative effect of dam construction on this region could be detrimental.