In the Democratic Republic of Congo (DRC), the deep erosion gullies carved by intense rainfall scar urban landscapes, destroy roads and homes, and directly threaten hundreds of thousands of people. Long underestimated, this phenomenon is now receiving international scientific recognition: a study conducted by Congolese researchers has just been published in the journal Nature, accompanied by an editorial highlighting the scale of the issue in the context of climate change.
This publication marks a major achievement for the team behind the Prevention and Mitigation of Urban Gullies (PREMITURG) project, a programme involving the University of Liège (ULiège), KU Leuven, the Official University of Bukavu (UOB), and the University of Kinshasa (UNIKIN). In August 2025, the work of two Congolese doctoral researchers, Guy Ilombe Mawe (UOB) and Eric Lutete Landu (UNIKIN), was published in Nature—a first for research dedicated to this phenomenon in the DRC.
A GROWING RISK FOR CONGOLESE CITIES
Between 2018 and 2022, PREMITURG conducted the first large-scale analysis of urban gullies in Kinshasa, Bukavu, and Kikwit. These massive chasms, which appear and expand rapidly after heavy rains, are multiplying in tropical cities lacking adequate stormwater management infrastructure.
“In the context of climate change,” explains Eric Lutete, an agronomist at the University of Kinshasa, “gully erosion is a serious problem for tropical cities, especially those built on sandy substrates like Kinshasa and other similar cities in the DRC. The issue is severe because it mostly affects people living in marginalized areas, on hillsides. These people have no choice but to live there for economic reasons, even though the land is not suitable for housing. They are therefore directly exposed to the damage caused by gullies: destruction of their homes, constant stress, and loss of human life. With future climate trends, extreme events will become more frequent, as our research confirms, increasing the risk of major damage.”
Supervised by Matthias Vanmaercke (ULiège and KU Leuven), Aurelia Hubert-Ferrari (ULiège), and Fils Makanzu Imwangana (UNIKIN), the project produced the first detailed mapping of the phenomenon and a nationwide estimate of its impacts. The results are alarming.
“Before the PREMITURG project,” explains Matthias Vanmaercke, the Belgian coordinator of the research, “we had an unknown geohazard. Of course, the Congolese population knew about the issue, but there was no quantified information. We worked on quantifying the events, mapping the gullies, and assessing the consequences for the population: how many people live in these areas? How many lose their homes each year? This is the work published in Nature: not a catalog of rare accidents, but rather an illustration of a systemic problem on a very large scale. In Kinshasa, more than 3 million people live in potential expansion zones, and 12,000 people lose their homes every year because of gully expansion. Our analyses, presented in Nature, show the exponential increase in damages—an indication of a bleak future.”
A LONG ROAD TO PUBLICATION
The study published in Nature is the culmination of several years of work. Guy Ilombe Mawe recalls: “It all started in 2018. As part of my master’s thesis supervised by Matthias Vanmaercke, we began mapping the gullies and found that nearly half of the major cities in the DRC were affected. We were the first to document the problem and quantify it in such detail.”
“The first comments from Nature’s three reviewers were positive,” adds Matthias Vanmaercke, “but they had numerous questions about how we quantified risk zones and explained gully expansion rates. We had to completely update our database, expand our impact analysis to the national scale rather than focusing only on Kinshasa, and model our calculations. The reviewers provided feedback at every step. There were four rounds of revisions over roughly two years. The exchanges were constructive, but each request was very strict.”
For the two Congolese researchers, the publication marks a turning point. “As for me, in Bukavu, it helped raise the profile of my colleagues and the reputation of my university (UOB),” says Guy Ilombe Mawe. “It also opens doors with authorities and donors.”
Eric Lutete adds: “As an agronomist, I received many discouraging remarks from colleagues who felt that by working on gullies, I was moving away from science. After the publication, everyone understood the seriousness of the research.”
A DEDICATED EDITORIAL IN NATURE
The journal also devoted its 27 August 2025 editorial to the study, acknowledging both the societal importance of the issue and the challenges faced by researchers in the Global South.
“It is exceptional for articles to be published in such a prestigious review,” notes Matthias Vanmaercke, “and even more so when Congolese researchers trained within the project are the first authors. We are particularly proud that the editors also dedicated the issue’s editorial to our work. Nature highlights the societal relevance of the issue while recognizing the considerable challenges that often accompany research in the Global South.”
BEYOND PREMITURG: TWO NEW PROJECTS
Building on this international visibility, the consortium is continuing its work. Since September 2025, the CO-URGENT project — funded by ARES and coordinated by Charles Bielders (UCLouvain) and Guy Ilombe Mawe — has aimed to establish a Congolese Observatory of Urban Gullies.
“We are going to set up a network of citizen observers… Our goal is to determine the rainfall thresholds that trigger gully expansion and to develop an early warning system,” explains Guy Ilombe Mawe.
A second project, SUGAR, funded by VLIRUOS, will evaluate the most effective strategies to prevent and control erosion in Kinshasa.
Together, these initiatives highlight the complementarity of cooperation programmes funded by ARES and VLIRUOS, as well as the growing synergy between Francophone and Dutch-speaking Belgian universities and their Congolese partners.
MORE INFO
- Article NATURE : here
- Editorial NATURE : here
- Kinshasa was hit by torrential rain during the night of 11 to 12 November 2025, flooding many neighbourhoods and causing damage to houses and roads, which were washed away by erosion. Watch the VRT report here.
Pictures : Matthias Vanmaercke – Eric Lutete – Guy Ilombe Mawe
