A field campaign to Bukavu is planned for the end of the month, it will be the opportunity to acquire a new set of UAV and DGPS acquisitions, that will help for the study of the kinematics of the landslide in the area. In addition, the know-how of the EOST on Terrestrial Laser Scanner will be roped in, acquisitions with the scanner being planned over different key landslides in the city of Bukavu.
The accurate characterisation of landslide processes remains a challenge in many regions. A fundamental tool to reach this goal is the availability of high-resolution digital representation of the surface topography, which greatly facilitates the study of landslide morphology, structures and mechanisms. To this aim, we used the acquisitions from a small Unmanned Aerial Vehicle (UAV) to reconstruct the topography of a recent deep-seated landslide (called Ikoma Landslide) located near the city of Bukavu, in Eastern DR Congo. The location of this landslide in a tropical environment and within the seismically active Kivu rift, as well as the presence of recent and highly apparent surface features make it a perfect natural laboratory to study landslide processes in such a data-scarce environment.
We complemented the study of the high-resolution topography with high-resolution satellite imagery and intense field surveys, which allows us to better discriminate its spatial and temporal evolution. We mapped the landslide structures, allowing the identification of three different landslide kinematic units (Zone I, II and III on the Fig.). These different sectors highlighting interactions within the landslide body but also the occurrence of multiple deformation episodes, all providing keys for the understanding of the mechanisms and the overall behaviour of the landmass. The satellite image time-series analysis allowed for further analysis of the different failures stages, also showing that deformation features were already present more than a decade ago. Altogether, these elements provide insights into the mechanisms and behaviour of this landslide, which does not seem to have been triggered by a specific event. Information gathered in this study helping to better evaluate the landslide hazard in the particularly data-scarce Kivu Rift region.