1 October 2015
Kothmale landslide in Sri Lanka: drone footage
Posted by Dave Petley
Kothmale landslide
On 25th September 2015 a landslide triggered by heavy rainfall fit the village of Kothmale (sometimes spelt Kotmale) in Sri Lanka, killing seven people. There is good quality drone footage of the landslide in the first part of this video on Youtube:
.
And there is also some good ground based footage of the landslide in this video:
.
This is a screenshot from one of the videos of the landslide Kothmale:-

Kothmale landslide via Youtube
.
Whilst this the source area from the same video:-

Kothmale landslide via Youtube
.
The main landslide appears to be a slip of a very thin layer of soil / regolith on a very steep bedrock interface. Note the soil layer at the top of the slope – it is possible that the slide started here and then entrained the regolith below. The landslide then appears to have turned into an open hillslope debris flow that has emtrained soil as it has passed through the tea garden. Sadly the houses in Kothmale were in the direct path of the flow, and would have offered little protection to the occupants.
My name is Kenichi HANDA. I was dispatched to National Building Research Organization (NBRO) in Sri Lanka from Ministry of Land, Infrastructure, Transport and Tourism in Japan.
NBRO is an organization investigating a landslide disaster of Sri Lanka.
Now I have been in NBRO as JICA (Japan International Cooperation Agency) Expert and Chief Advisor of ‘Technical Cooperation for Landslide Mitigation Project’
JICA Survey Team, include me, had oppotunity to conduct field survey on this Kothmale landslide Last October.
That report had published in JICA Sri Lanka Office Home Page
http://www.jica.go.jp/srilanka/english/office/topics/151216_01.html
Please refer the report and do not hesitate to contact me if you’ve any questions.
Thand you.