The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.
On 10 to 13 September 2024, the remnants of Typhoon Yagi swept across Thailand and Myanmar, bringing exceptional rainfall. Obtaining accurate information about the impacts of such events in Myanmar is extremely difficult – the ruling military government has poor international relations and there is an ongoing civil war. However, very unusually, the Myanmar government sought international humanitarian assistance, with reports of hundreds of fatalities.
One report, by BNI, suggested that up to 30 people had been killed in landslides in Loilem Township, southern Shan State. Loilem is located at [20.9292, 97.5649], so I have been waiting for good quality satellite imagery to be able to take a look. Planet Labs collected a good image on 19 September, although this covers only a portion of the area affected. But the imagery that is available is deeply shocking.
This is satellite image of an area centred on [20.5318, 96.4398], collected on 16 May 2024, before Typhoon Yagi struck:-
And this is the same area after Typhoon Yagi:-
And for reference, here is an image compare of the area:-
The image shows hundreds of shallow landslides in even this comparatively small area. These landslides have generated a huge amount of sediment that has entered the river system, causing mayhem along the channels.
At this stage it is not possible to estimate how large the area affected might be – the imagery is incomplete and there is considerable cloud cover at this time of the year – but it is extremely extensive.
The impacts are not just focused on the lower population density upland areas. The Planet Labs image below shows the area around two villages, Kyaung Kone [20.3899, 96.3784] and War Hpyu Taung [20.3802, 96.3715]:-
Once again, there are hundreds of slope failures in this small area (the image is about 7.5 km wide), and it is clear that both villages have been hit directly by the landslides.
Inevitably, this has had a terrible impact downstream. The image below shows the area around a village named Myin Nar [20.4420, 96.2288]:-
Huge amounts of sediment laden water has flowed across the land in this area. Myin Nar is in the upper central part of the image (with a black marker) – it appears that the village has been extensively flooded.
The full scale of the disaster in Myanmar in terms of human casualties might never be known, and the landslide impact may take some months to uncover, given the cloudy conditions. But there is no doubt that a major landslide disaster has occurred in Myanmar, triggered by Typhoon Yagi.
Reference and acknowledgement
Planet Team (2024). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/
