Kathmandu [Nepal], August 31 – A barrier lake formed in China’s Gyirong county in the Tibet Autonomous Region has almost completely drained but significant risks remain in a large erosion pit and three inundated areas downstream, Chinese authorities said.
According to China’s Ministry of Water Resources, the latest assessment based on drone footage, panoramic images and information from emergency teams at the site found that the lake formed on the Purepu Tsangpo River had almost completely emptied and the river’s flow had returned to normal.
However, the ministry warned of continuing risks along the Chhuchen Khola which flows into the Purepu Tsangpo River, China Daily reported.
About 1.4 million cubic metres of water remains in an erosion pit in the river around 5.6 kilometres upstream from the barrier lake. The pit is about 800 metres higher than the lake.
Satellite imagery showed that the water-covered area of the pit stood at about 1,08,000 square metres as of 11:23 am Saturday,down by 19,000 square metres from 7 am.
Three inundated areas were also identified within 2.5 kilometres downstream of the pit. Their combined surface area was less than 70,000 square metres.
The ministry said the erosion pit and the three inundated areas posed “significant risks and hidden hazards.”
Another barrier lake formed 2.8 kilometres downstream of the original lake after a landslide occurred on the Nepal side on Saturday. The new lake has since breached due to incoming water with flow returning to the river’s normal channel.
Authorities warned that further landslides along riverbanks could trigger the formation of new barrier lakes.
China’s emergency management authorities said 16 people had died and 546 remained missing in the Gyirong Port area along the China-Nepal border as of 6 pm Saturday.
