The Brahmaputra river has been turning black mysteriously. It came to notice in October, when the Siang river, Brahmaputra's main tributary, in Arunachal Pradesh started showing signs of turbidity and then two months later, the river has turned into visibly black.
The Brahmaputra river has been turning black mysteriously. It came to notice in October, when the Siang river, Brahmaputra’s main tributary, in Arunachal Pradesh started showing signs of turbidity and then two months later, the river has turned into visibly black. According to an earlier assumption, this was due to the possible construction activity on the Chinese side. However, there was no consensus, or official word, on the matter, and it was a mere speculation. Raising curtain from the mystery of clour change, Pradeep Kumar, member (river management), Central Water Commission, told The Indian Express that the lab tests have established that the water has darkened due to turbidity typically caused by landslides. He said, “There is no foul play involved. However, landslide-induced turbidity usually subsides within a week. So we are examining the situation through satellite images as the affected area is not within our territory. We will get a clearer picture soon.”
As per the report, the accumulating debris has caused partial blockages at three locations, forming natural dams on 6 km of the river across a 12-km stretch in China. The worry for India is that these three dams may merge and eventually give away to result in a deluge downstream. A preliminary 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 probably explains the prolonged turbidity.
The darkening of the Brahmaputra came to national attention earlier this month when Ninong Ering, a Congress MP from Arunachal, requested Prime Minister Narendra Modi to take up the matter with China. In his letter, Ering attributed the phenomenon to Chinese construction activity, citing a news report to support his claim. The report, published on October 30, detailed China’s purported plan to build a tunnel to divert water from the Yarlung Tsangpo in Southern Tibet to Taklamakan desert in Xinjiang province. The Chinese government has denied it has such a plan, calling the report false.
Meanwhile, a sample tested by Arunachal’s Public Health Engineering department confirmed the turbidity of the Siang’s waters was several times higher than the permissible limit. Soon, reports of fish and animals dying from the polluted waters started to emerge from the Siang Valley. There was a public outcry, forcing Chief Minister Pema Khandu to ask the central government to take the matter up with Beijing.
The 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.
(With inputs from The Indian Express)