NEW DELHI: The deadly glacier burst in Tibet which triggered a wall of water and mud to drown the narrow gorges of Bhote Kosi river in neighbouring Nepal has intensified scrutiny of China’s construction and dam‑building activity in the roof of the world.
Construction in the highly fragile Himalayas can cause erosion, trigger earthquakes and landslides and set off a chain of ecological events from glacier bursts to snow avalanches which in turn can cause floods and a whirlwind of destruction downstream.
Water bomb: China’s destabilising fragile Himalayas
The magnitude 4.4 earthquake in Tibet in the early hours of Wednesday may or may not have caused the glacial burst which drowned Nepali towns and villages, the fact remains that China has been building a series of militarised concrete villages and towns in the fragile Himalayas, along with missile silos, connecting roads and military airports, throughout the Tibetan part of the Himalayas, which has been recorded by numerous satellite imagery.
Last year, China also started building the massive US$170 billion hydro-electric power project and dam on the Yarlung Tsangpo river near the border with India’s Arunachal Pradesh. This dam once finished is expected to generate 300 billion kilowatt hours of electricity and will be the largest single hydropower project in the world.
The danger it poses downstream in the case of a disaster is obviously something that all the regions through which water flows, should be wary of. The Yarlung Tsangpo river flows and connects to the Siang river in Arunachal Pradesh’s Gelling to move into Assam as the Brahmaputra, after being connected by more rivers.
The entire Himalayan belt is seismically a high-risk zone. Scientists at Caltech and ISRO have identified four specific segment in the 2,000 km long Himalayan arch where seismic activity is building up enormous stress, which can trigger earthquakes.
The Brahmaputra factor: Alarm bells for India, Bangladesh
The danger of a seismic event occurring, triggered by the huge construction activity in the high Himalayas could possibly lead to a chain reaction triggering a dam burst with devastating effects on the lower riparian nations of India and Bangladesh as the Brahmaputra flows downstream from Assam into Bangladesh to join the mighty Padma before emptying into the Bay of Bengal.
The Brahmaputra basin already suffers from high sediment loads, steep gradients and seismic activity of its own; any shock flood carrying with the debris of a very large upstream structure can magnify downstream vulnerability in Assam, Arunachal Pradesh and, further on, Bangladesh.
Reservoir‑triggered seismicity is a grim possibility
According to reports published earlier this year by South China Morning Post, warnings that the giant hydro-electric project sits on a seismic fault line have been made by Chinese geologists themselves.
A Chinese-language journal Sedimentary Geology and Tethyan Geology, has also said engineers have been advised to take steps to mitigate the risk of landslides and collapses.
Other researchers have flagged the possibility of reservoir‑triggered seismicity (RTS), where the weight of stored water itself causes stress on underlying faults and inducing earthquakes.
Indian officials say that “Even without failure, the dam gives China significant operational control over a large share of the river’s flow. And the possibility of weaponizing water at a later stage is something which cannot be ruled out.”
What compounds the problem for India is that China has not shared hydrological data on Yarlung Tsangpo and other rivers originating in Tibet with lower riparian states, whether they are India or Nepal or for that matter Bangladesh, which is politically closest to China at this point of time. - The Statesman/ANN
