8 July 2010
A new landslide video
Posted by Dave Petley
Regular readers will be aware that I like to highlight new landslide videos as and when they appear, not least because fellow educators and academics find them to be useful teaching tools. In addition, watching the videos reminds us of what we are attempting to manage, and can also provide insight into processes. Latest in the list is this one, which appeared on the web last week:
It appears to be a dry earthflow, but the location, trigger (the weather appears to be dry), etc are all unclear. Judging by the accents, South Asia looks to be the general area. The chap in the forground with the orange coat and a radio looks like he may have come from a construction site, so road construction may well be a factor.
Listen carefully to the comments picked up by the microphone. “Dear me, no traffic again!” is an understatement in the true British style.
Dave Petley is the Vice-Chancellor of the University of Hull in the United Kingdom. His blog provides commentary and analysis of landslide events occurring worldwide, including the landslides themselves, latest research, and conferences and meetings.
The 04 January landslide was so large that the debris filled the river and then went on to rise on the Southern side of the river. Hence the debris on Southern side was higher than the Northern side. Your photograph very clearly explains this. The high volume of debris has remained at the landslide point for more than six months and logically should have settled in permanent strata. The huge earth moving vehicles have moved all over the area which would have settled the debris further. The dam was constructed naturally over a period of time since 2002 onwards and only a small gap was open for the river to flow. The height of dam was already more than 20m or so before the landslide. The spillway has been constructed towards the North of the landslide area where the height of the debris was the lowest. If the dam fails by GLOFs or any earthquake (very rare but still a possibility) the debris on the South will come down and block the spillway one more time. If the dam does not fail and there is GLOF then the situation is worse. So the resolution of the Gojal Lake by natural means seems to be very remote. The GB government should get more experts like Dr Dave and others to work for resolution of the lake at the earliest.