25 June 2015

Daning River: a landslide-induced tsunami accident on a tributary of the Yangtze

Posted by Dave Petley

Daning River landslide

A very significant landslide occurred yesterday (Wednesday) evening on the Daning River, a tributary of the Yangtze, in Wushan County, Chongqing.  Global Times has an image of the landslide site:


The landslide triggered local tsunami waves on the river that swamped a number of fishing boats:


Fortunately as the landslide occurred at 6:40 most of the vessels were reported to have been vacated.  Nonetheless one person is reported missing and a further four were injured.

The landslide is intriguing.  The images seem to show a low river level (possibly the river level is being drawn down in preparation for the rainy season?) and there is no mention of a rainfall trigger.  The materials forming the landslide scar seem to be fine-grained and quite homogeneous.  The fortunate element is that the landslide did not affect the houses located nearby.

The site of the landslide is only 110 km upstream of the Three Gorges Dam, such that the river level has been elevated by the impoundment of the reservoir.  This case is likely to further raise fears of the potential for significant landslides on the banks of the lake.