27 September 2015
Late in July extremely heavy rainfall affected Chin Division in Burma (Myanmar), triggering extensive landsliding and flooding. This event has been very little reported, but all of the indications were that the impacts were substantial. I have been trying to track down further information about this event ever since, and have now come across some information about it. In particular, it is now clear that the rainfall triggered what appears to be at least one giant (i.e. > million cubic metre) landslide. Whilst the area has been cloud covered since the disaster, Unosat have managed to obtain a partially cloud-free Pleiades image of the area, and have posted an interpretative image on their website:-
This is a very large landslide – the red area is the lake that has formed behind the landslide dam – this is 34 hectares in surface area according to UNOSAT. The part of the landslide that is visible here appears to be more than a kilometre wide and at least 3 km long. But note that all we are seeing here is the deposit – the track and source are somewhere beneath the cloud off the image. Colin Stark has very kindly overlain the image onto the Google Earth imagery of the area, giving an indication of the portion of the landside that we can see, and a symbol to indicate the likely source area:
As the monsoon withdraws the chances of getting a decent satellite image of the Tonzang landslide will increase, and this is a landslide on such a scale that it will be readily identifiable on Landsat 8, and suchlike. Watch this space!
Meanwhile, there is a blog featuring landslides in the Hakha City area of Chin Division, Hakha City, being run out of the USA. It has a fantastic selection of images of some of the landslides triggered by this heavy rainstorm event:-
This area is 150 km or so south of the Tonzang region, so I don’t think the landslides featured here is that in the UNOSAT image. If so, it suggests that this was an extremely large landslide inducing rainfall event, probably the most important of the year to date.