A massive landslide of about 10 million cubic m (350 million cubic feet) blocked a river in central China's Hubei Province, resulting in a barrier lake that prompted authorities to evacuate more than 8 000 residents on Tuesday, July 21, 2020.
The barrier lake was formed around 21:30 UTC on July 20 (05:30 LT on July 21), when a massive chunk of earth fell on the Qingjiang River-- a tributary of Yangtze River in the Enshi Tukia and Miao Autonomous Prefecture, according to the city's flood control and drought relief headquarters.
An hour later, a huge chunk of 1.5 million cubic m (53 million cubic feet) of earth slid into the river, as reported by Fu Qiang, an engineer with the Hubei Geological Bureau, at a press conference late Tuesday night.
Fu added that the landslide body is constantly changing.
On the same day, around 02:15 UTC (10:15 LT), water from the upper reach broke through the top of the lake, discharging at 200 cubic m per second (7 000 cubic feet per second), easing the risk of the dam breaking.
A total of 8 397 residents of 1 963 households from the affected areas have been evacuated as of 07:00 UTC (15:00 LT), mayor Su Yong confirmed.
In the analysis by Dr. Dave Petley of The Landslide Blog, it was stated that the landslide appears to be a large, mobile earthflow-type.
"The nature of the material suggests to me that it is probably a failure in a thick loess deposit, although this needs to be confirmed," he wrote.
The original failure is deep-seated and broad, and it appears that there is little to no failure in the underlying bedrock that forms the gorge, Petley added.
Image credit: 神圣使命
On Wednesday, July 22, China's state weather bureau said the country was pounded by fresh bouts of torrential rain this week, further raising threats of flooding throughout the nation.
Red alerts have been declared in the provinces of Jiangxi and Anhui, which are bisected by the Yangtze. The water resources ministry also warned that water levels in the Yangtze River and adjoining lakes would continue to swell.
The severe flood situation in China has left millions affected, damaged almost 30 000 houses, and caused more than 150 fatalities.
Featured image credit: 神圣使命/YouTube