Evidence presented in a paper recently published in Landslides journal suggests that changes seen on satellite images could have been used to predict the Maoxian landslide in China’s Sichuan Province.
The authors of The Maoxian landslide as seen from space: detecting precursors of failure with Sentinel-1 data paper studied 45 satellite images taken before the slope failure on 24 June this year, which killed more than 100 people.
Using the Insar technique to compare the images the authors were able to detect 40mm to 60mm of ground movement over a three year period before the slope failed with images taken in spring 2017 presenting evidence of accelerated movement.
Landslide specialist and pro-vice chancellor of research and innovation at University of Sheffield Dave Petley said: “This is a really important and interesting paper. It demonstrates that Insar can be used to detect landslide precursors at a scale that is useful, and that the technique can extract the rate of movement to the extent that acceleration to failure can be detected.
That opens up the possibility – albeit with a great deal of additional work – of using these new satellite tools as a warning system. This is fundamentally exciting.
“The study also provides another detailed archive of the actual nature of these precursory movements. And, importantly, it demonstrates how a first time failure develops across a slope.”