The Urni landslide: a recurring slope failure in India

On Monday 19 December 2022 a significant slope failure occurred at the Urni Landslide in Kinnar, Himachal Pradesh in northern India.  This event was notable for the fact that it was caught on camera by users of National Highway 5, which passes close to the landslide site:-

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Fortunately there was no loss of life at this site, but the road was closed for repairs.

The landslide is located at 31.519, 78.129 on the banks of the Sutlej River in very steep terrain.  It is captured beautifully in Google Earth:-

Google Earth image of the Urni landslide in Kinnaur, India.

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The archive images of the site on Google Earth provide a classic case study of the development of a landslide through time – take a look.  The slope is now deeply problematic – note the very the diversion of the road across to the other bank of the river for a short section to try to avoid the landslide toe/

The Urni landslide was written up in an open access paper (Kumar et al. 2019) that was published in the journal Geoscience Frontiers.  The aim of the paper was to model a major failure that might dam the river.  The authors noted that the landslide has developed in gneissic rocks on steep slopes, and that there are numerous cracks upslope of the existing failure, indicating a high probability of future events.  This came to pass this week, at least in part.  The failure was initially a structurally-controlled wedge failure, but has developed into a much more complex landslide.

Movement is primarily triggered by heavy rainfall in the monsoonal climate, but the precarious nature of the topography inevitably means that collapses can occur at any time.

Of interest at this site is the ongoing works to construct the Karcham Wangtoo Hydro Power Project – some elements of this are visible in the image above.  It has long been asserted that these works have led to an increase in the occurrence of landslides in this area.  For example, the South Asia Network on Dams, Rivers and People has an article from 2014 documenting some of the impacts.  Construction started in 2005.

Of course, of immediate concern is the potential risk to the houses upslope of the Urni landslide.  In October 2022 the crown of the landslide was perilously close to the houses.  A major failure could exacerbate this situation.

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Reference