17 June 2019
Longyan City: a dramatic landslide in deeply weathered soil
On 13th June 2019 a strong rainstorm struck Longyan City in Fujian province, southern China, triggering a major landslide that was captured on CCTV. The video has been widely shared online, and is available on Youtube:-
This is just one of many rainfall-induced incidents across southern China, with reports on the BBC suggesting that up to 61 people have been killed. The landslide in Longyan is reported to have killed one person, who was sitting in one of the cars.
The still from the video below catches some of the key features of the landslide:-
The video shows that the landslide was very highly mobile, implying that the soil has undergone liquefaction during failure. The material is a deep red colour, implying that it consists of deeply weathered soil and regolith, which is not unusual in the humid, subtropical climate of the southern part of China. The interaction between the landslide and the vehicles is interesting – note that they are pushed forward by the landslide rather than being buried or inundated. This illustrates the points that I made a dacade ago about rescuing the victims of landslides. It is crucial to understand the landslide mechanism and type of flow as many (but by no means all) landslides tend to bulldoze objects in their path, rather than burying them in situ.
In this case it will be interesting to understand better the underlying causes of the landslide. The failure appears to have swept down a slope that is at least partially vegetated, although that vegetation does not look like original forest to me. I wonder if the slope was but in order to create the bench for the road?