Nanyu Township: a very large landslide in Gansu Province on Thursday 12th July 2018

Xinhua has posted some images of a very large, partially valley blocking landslide that occurred at Nanyu Township in Zhouqu County, located in Gansu Province, China.  The landslide, which was triggered by rainfall, is reported to have a volume of about 5 million cubic metres.  The best image of the landslide itself is this one, from Xinhua, which shows the lower portion of the displaced mass.  It is clear that it has greatly constricted the river channel:-

The large landslide at Nanyu Township in Zhouqu County, northwest China’s Gansu Province. Image via Xinhua.

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The partial blockage of the river has caused extensive flooding:-

Flooding upstream of the landslide at Nanyu township in Gansu Province. Image via Xinhua.

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On Google Earth the area affected by the landslide appears to be as below.  The location is 33.719, 104.421:-

Google Earth image of the landslide at Nanyu township in Gansu Province

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My interpretation of this is that the failure is on a large, pre-existing landslide.  From the Google Earth imagery considerable slope modification has occurred.  The section of the slope that has failed in this event is shown in the image below:-

Google Earth image of the portion of slope that failed in the Nanyu township landslide

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This section of slope shows considerable signs of distress and instability, and it is interesting to note that the river has a series of rapids in this area.

Gansu Province has a long landslide history.  The following posts highlight landslides in this part of China:-

• Heifangtai terrace: spectacular loess flowslides in Gansu Province, China
• Spectacular landslides from the Gansu earthquake this week
• First image from the Gansu landslide
• Update: the Gansu landslide
• First video of the Gansu landslides
• Update: Dramatic increase in the loss of life in the Gansu landslide
• Two interesting landslide videos from Congjiang, China and Manali, India
• Two dramatic new landslide videos from China
• Zhouqu landslide – NASA satellite image