29 July 2016

Landslides in Nepal from the 2016 monsoon

Posted by dr-dave

Landslides in Nepal from the 2016 monsoon to date

Nepal has been very seriously affected by the 2016 monsoon, with prolonged heavy rainfall causing landslides across a large swathe of the country.  The consequences have been severe – I have been trying to collate information on losses based upon newspaper reports.  To date I have recorded 73 landslide related deaths in 19 separate landslides this week.  Of course many thousands more have been severely affected as roads and buildings have been damaged and destroyed.  Ekantipur has this powerful image of one of the fatal landslides – this one killed a 12 year old girl in Parbat:

2016 monsoon

A landslide triggered by the 2016 monsoon in Nepal, via eKantipur

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This is a complex landslide that in the lower reaches transitioned into a debris flow.  Note the location of the structures in relation to the path of the flow.

As usual a key issue has been the role of poorly engineered roads in triggering landslides, and in many places there are reports that roads have played a key role in the failures.  So, for example, in Pholpi VDC in Pyuthan, which at the moment seems to have suffered the highest number of losses (27 deaths in my dataset), MyRepublica has this quote:

“We were actually not at any risk. The newly-constructed rural road is the reason for these landslides,” said Shivaraj Subedi, a local. “The soil was greatly loosened up after the use of an excavator to construct the road. Loose soil coupled with heavy rainfall led to this big disaster.”

Similarly in Bajura poor quality road construction has been identified as a key issue:

Haphazard use of heavy equipment for road construction in Bajura has affected nearby human settlements negatively….  “Although road construction is a good thing, the work is being done without properly considering the geographical sensitivity of the area, and many human settlements are in peril,” said Tula Thapa, a local teacher.  At the Phalasain-Kuldevmandau road construction site, locals have complained of increased threat of landslides triggered by the projects.

This is not new of course, and I have been banging this drum for years.  For example, back in 2013 I highlighted an example of landslides being triggered by poor quality road construction in Gorkha District.  Needless to say the problems have continued unabated.

Finally, in Sindhupalchok district, which was severely affected by landslides in the 2015 earthquakes, landslides are also causing serious difficulties.  The Himalayan Times reports that:

Most of the rural roads in Sindhupalchok district have been obstructed due to landslides triggered by incessant rainfall.

There is evidence that humans have played a role here too.  When the Araniko Highway to Tibet was blocked by landslides last week, a new access road started to be opened using bulldozers.  Four days ago the Kathmandu Post reported that:

Heavy rains in Sindhupalchok damaged the construction works for the 26-kilometre alternative route to connect Barhabise with Tatopani on Thursday night, after flash floods two weeks ago swept away the parts of Araniko Highway in the district.  Divisional Road Office chief, Ashok Tiwari, said 50 percent of the construction they had accomplished, a 13 km track  from Barhabise till Jambu, in the last few days was destroyed by landslides. Khorang, Jhyalebhir and Dakalang are seeing the worst landslides.

This was so tragically predictable.  When this was announced I wrote the following in an email to a friend in relation to the initial reports of them building this track:

Pragmatic maybe, but this is an area mantled with many quasi-stable very large landslides.  These hastily constructed roads trigger instability.  This is likely to compound the problems in the short term.

It really did not need a landslide specialist to know this.  If Nepal wants to reduce its losses to landslides it must get a grip on this poor quality of road construction.