What is the issue: Recently BJD MP Bhartruhari Mahtab had raised the issue of the contamination of the Brahmaputra river water. According to him, the contamination may have been caused due to the construction of a dam by China on a tributary of the Brahmaputra. He also demanded that since India is a riparian country hence China is obliged to share all hydro-meteorological data with India. If china fails to do so, government should raise the matter at all international forums. Even Assam Chief Minister Sarbananda Sonowal had raised the issue with the Prime Minister. He was assured by External Affairs Ministry that they had started an exhaustive study after contacting authorities in China.
Real cause: An initial study by two researchers from Bengaluru-based National Centre for Biological Sciences (NCBS) and Ashoka Trust for Research in Ecology and the Environment (ATREE) shows that quake-induced landslides on the river continued for over three weeks which causes massive landslides. Lab tests have confirmed that the water has darkened due to turbidity typically caused by landslides and not by Chinese activities. Even in April 2000, a massive landslide on the Yigong-Tsangpo blocked the river and created a 90-metre deep natural reservoir across 2.5 square kilometres. This natural dam gave way in June, flooding areas as far as 400 km downstream, sweeping away large swathes of forest, and destroying over 50 villages in Arunachal Pradesh and Assam.
About the river: The Yarlung-Tsangpo river cuts through the world’s tallest gorge between Gyala Peri and Namcha Barwa before merging with the Yigong-Tsangpo river and taking a 180-degree turn southward to flow into Arunachal Pradesh where it is known as Siang. Further downstream, major tributaries — such as the Lohit and Dibang — join the Siang to make it the Brahmaputra.
