13 January 2020
Burundi: Planet Labs and Sentinel images of the 4 December 2019 landslide disaster
On 4 December 2019 intense rainfall triggered a significant, if under-reported, landslide disaster in Burundi in Africa. Whilst there were problems in many regions of the country, the most serious impacts occurred in the area around Nyempundu, in Mugina commune in Cibitoke. If you want to take a look, this is around -2.62, 29.09.
According to the Wikipedia page about the disaster, at least 38 people were killed by landslides in this event, and there was substantial damage to infrastructure such as bridges and roads, as well as loss of houses. The response has inevitably been hampered by the remote location.
This is not an area in which it is particularly easy to get good satellite imagery due to cloud and water vapour. However, Planet Labs captured this PlanetScope image on 7 December 2019 showing the landslides in the most heavily affected area:-
The imagery appears to show multiple shallow landslides with some evidence of debris mobilisation through the channel system in the form of debris flows. In some sub-catchments much of the topsoil appears to have been removed.
These are the same landslides, shown in a Sentinel-2 L1C image, via Sentinel Hub. The image is dated 14 December 2019:-
Although it is lower resolution, the advantage of Sentinel is that it is easy to generate an NDVI image, in which the contrast between vegetation (which appears red) and bare soil (which appears tan) is clear. This is an NDVI image from the above Sentinel image, which highlights the landslides:-
It is clear that in this area of Burundi a substantial landslide disaster has occurred. Of course the damage to the hillsides and sediment in the channel will cause long term problems for the local population.
Planet Team (2020). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/