For the second time in a fortnight, China has alerted India of a possible flood-like situation in the Brahmaputra river in Arunachal Pradesh after a landslide blocked water upstream in Tibet, a senior water resources ministry official said on Wednesday, 31 October.
The alert of a landslide and subsequent formation of an artificial lake was informed to India on late Monday, 29 October, evening separately through diplomatic channels and the mechanism under which China shares hydrological data with Brahmaputra, the official told PTI.
"As per latest information received from #Chinese side, the estimated blocked water storage volume at landslide location (#Milin Section of #Yarlung #Zangpo in #Chinese Territory) at 6.30 hrs IST (9 hrs Chinese time) on 31st Oct 2018 is 337 MCM," the Central Water Commission tweeted.
When Was the First Alert Issued?
On 17 October, China had communicated to India about a landslide near Jiala Village in Milin County in the lower ranges of Yarlung Tsangpo river in Tibet, which led to the formation of an artificial lake.
As the water started breaching the lake, the districts along the Brahmaputra river in Arunachal Pradesh were put on high alert for possible flash floods.
The Yarlung Tsangpo, as it is referred to by China, is known as Siang in Arunachal Pradesh and Brahmaputra after it reaches Assam.
"This time the landside occurred at the same place and has again led to creation of an artificial lake, which has now started breaching. However, the situation is not grave as it was a fortnight ago," he said.
What Led to India and China Sharing Data on Brahmaputra?
From May, China resumed sharing hydrological data on the Brahmaputra and Sutlej rivers. In April, the two sides had signed an agreement to share data on Brahmaputra and Sutlej.
For the Brahmaputra river, data was shared by China from 15 May, while it started sharing data for the Sutlej from 1 June until 15 October.
However, the two recent events have taken place after the data sharing period was over.
“The agreement also states that data has to be shared in case of an emergency and they (China) have done that.”Senior Water Resources Ministry Official
What Were the Dangers Discussed in First Alert by China?
Authorities in Arunachal Pradesh’s Itanagar asked people not to venture into the Siang river flowing through Upper Siang district following a landslide in Tibet which could trigger possible floods in the state.
The possibility of floods in the Siang river looms large if the artificial dam, formed by the landslide in the Yarlung Tsangpo river at 10 am on Monday, 29 October, breached, according to officials.
The Yarlung Tsangpo river is known as Siang in Arunachal Pradesh and Brahmaputra in Assam.
Upper Siang DC Duly Kamduk said in a circular on Tuesday that the Department of Disaster Management had informed the Upper Siang district administration about the landslide at the Milin section of the Yarlung Tsangpo river and the possibility of floods in the Siang.
The circular also stated that there has been an unprecedented decrease in the volume of water in the Siang river at Tuting since Monday night.
Advising people to take precautionary measures, the DC asked them not to panic or create panic.
Central Water Commission superintending engineer of Guwahati-based circle office, Ravi Ranjan said:
“The External Affairs Ministry on Monday night informed the Central Water Commission (CWC) about the landslide that occurred in the Yarlung Tsangpo River at the same place where another landslide had occurred a fortnight ago.”
There was nothing to panic as only 1.44 meter of water volume had decreased since 10 pm Monday to 8 am Tuesday, Ranjan said.
According to the hydrological data of the CWC, the water level of the Siang River at Tuting is falling at the rate of one cm per hour.
Since it is winter season, the volume of discharge of water in the river would come down by 40 to 50 percent, the DC said.
(With inputs from PTI.)