Landslides in tropical Africa

Dangerous but often overlooked

In 2017, hundreds of people perished in landslides in tropical Africa. Alas, we still know very little about the phenomenon in this part of the world. Liesbet Jacobs has just completed her doctoral thesis investigating the processes leading to landslides in wet tropical areas, with hopes that this will help predict when and where these hazards are going to hit.

Landslides in tropical Africa

Each year, landslides cause human losses and damage to infrastructure and property in many areas around the world. ‘These landslides are not well-documented in tropical Africa,’ explained Liesbet Jacobs, a researcher at the VUB and the Royal Museum for Central Africa (RMCA) in Tervuren.

‘Yet the damage can be considerable, as was unfortunately the case in August 2017, with more than 500 victims in Sierra Leone and over 200 in DR Congo. The devastating impact of these landslides are in sharp contrast to the dearth of knowledge regarding these geological processes.’

‘Moreover, the damages and losses associated with landslides are bound to worsen in the future, in light of increasing demographic pressure and the deforestation and modifications in soil use that this implies. Climate change is also expected to trigger greater and more intense precipitation in these areas.’

Case study: Rwenzori Mountains

Liesbet Jacobs wrote her doctoral thesis on landslides in the Rwenzori, a mountain range located on the border between Uganda and DR Congo.

‘Using a combination of fieldwork and the analysis of archives and satellite images, I studied landslides so I would better understand where and when they appeared. I found in particular that soil type and geomorphology have a strong influence on them.’

‘My colleagues and I then created susceptibility maps for the region to highlight risk zones. Over there, we also established a crowdsourcing project that allows local residents to collect data on natural hazards using their smartphone.’

Part of the large-scale AfReSlide project

While Jacobs’s thesis was written in affiliation with VUB and RMCA, her work is part of the AfReSlide project. Funded by Belgian Federal Science Policy (BELSPO) for the 2013-2018 period, the project is a collaboration between RMCA, VUB, KU Leuven, and ULB.

AfReSlide is centred around identifying culturally, technically, and economically feasible resilience strategies, at both government and individual levels, for landslides and the damage and human losses they cause.

In February 2018, Jacobs and her colleagues returned to Uganda to turn over the results of her thesis to public authorities. These decision-making tools should help reduce the damage associated with landslides. The results were transmitted to the national, regional, and local levels.