François Kervyn

Royal Museum for Central Africa · Department of Earth Sciences

In many administrative entities, there is little information on the accessibility of critical resources such as food, water, healthcare and fuel. Yet the lack of accessibility to critical resources can be a risk-mitigating factor. Indeed, people who are not physically threatened by a hazard can be put at risk by the fact that they lack critical res...

Impacts induced by natural hazards are increasing globally. Some of these hazards, such as volcanic eruptions, cannot be prevented. Thereby, mitigating impacts is crucial, especially in densely populated areas, like in Goma city in the eastern Democratic Republic of Congo, which is exposed to volcanic threats from Nyiragongo. Mitigation requires th...

Landslides and flash floods are geomorphic hazards (GH) that often co-occur and interact and frequently lead to societal and environmental impact. The compilation of detailed multi-temporal inventories of GH events over a variety of contrasting natural as well as human-influenced landscapes is essential to understanding their behavior in both space...

Assessing volcanic hazards in locations exposed to multiple central volcanoes requires to consider multiple potential eruption sources and their respective characteristics. While this is common practice in ashfall hazard assessment, this is generally not considered for topography-controlled volcanic flow processes. Yet, in volcanic areas with close...

Connaître Gérer Réduire Aménager Informer Surveiller Prévenir les géorisques majeurs aux niveaux régional et local pour assurer la protection des populations et un développement durable des territoires CONTEXTE En Afrique, et particulièrement dans la région centrale, les pays sont exposés à de nombreux aléas d'origine géologique, qui menacent les p...

Rapid urbanization, demographic pressure, and sprawl of cities are key factors in the vulnerability and damage related to geo-hydrological hazards. Dysfunctional urban services that favor informal settlements are at the forefront of elements that increase vulnerability. Cases of cities that suffer from geo-hydrological hazards are increasingly repo...

In urban areas, networks and life-support systems, such as roads, power lines and drinking water pipes, are key infrastructures which contribute to the functioning of the city. Their damaging or destruction can lead to harmful consequences for the population. Such situation has already occurred in several African cities following the impact of a ha...

Volcano monitoring requires simple techniques to rapidly identify the cause of volcanic unrest. The so-called RSAM (real-time seismic amplitude measurements) technique, used in many observatories, is a good example of extracting information from seismograms with minimal processing. Built on a similar principle, the more recent seismic amplitude rat...

Risk perception is an essential element to consider for effective risk management at the time of eruption, especially in densely populated cities close to volcanoes like Goma in the east of the Democratic Republic of the Congo, which is highly exposed to volcanic hazards from Nyiragongo. The perception of volcanic risk involves the processes of col...

The movement of large, slow-moving, deep-seated landslides is regulated principally by changes in pore-water pressure in the slope. In urban areas, drastic reorganization of the surface and subsurface hydrology—for example, associated with roads, housings or storm drainage—may alter the subsurface hydrology and ultimately the slope stability. Yet o...

Landslides and flash floods are geomorphic hazards (GHs) that often co-occur and interact. They generally occur very quickly, leading to catastrophic socioeconomic impacts. Understanding the temporal patterns of occurrence of GH events is essential for hazard assessment, early warning, and disaster risk reduction strategies. However, temporal infor...

Classical mechanisms of volcanic eruptions mostly involve pressure buildup and magma ascent towards the surface1. Such processes produce geophysical and geochemical signals that may be detected and interpreted as eruption precursors1–3. On 22 May 2021, Mount Nyiragongo (Democratic Republic of the Congo), an open-vent volcano with a persistent lava...

Understanding risk perception and factors controlling the willingness to implement DRR actions is essential for effective crisis management, especially in densely populated cities close to volcanoes, like Goma in the East of the DRC. Willingness to implement DRR actions is assumed to be influenced by risk perception, but also by the individual eval...

The willingness to implement risk protective measures (protection motivation) differs between individuals and informing people at risk about the risk they face may not be sufficient to generalize the implementation of protective measures. Therefore, an assessment of the individual psychological appraisal of the risk (threat appraisal) and of the ri...

Risk perception is an essential element to consider for effective risk management at time of eruption. This is especially the case in densely populated cities close to volcanoes like Goma in the East of the Democratic Republic of Congo highly exposed to volcanic hazards from Nyiragongo. The perception of volcanic risk involves the processes of coll...

Landslides and flash floods are geomorphic hazards (GH) that often co-occur and interact. They generally occur very quickly, leading to catastrophic socioeconomic impacts. Understanding the temporal patterns of occurrence of GH events is essential for hazard assessment, early warning and disaster risk reduction strategies. However, temporal informa...

Nyiragongo is one of the rare volcanoes on Earth hosting a lava lake. However, the understanding of its plumbing and lava lake systems remains limited, with, until recently, only sporadic or time‐limited historical observations and measurements. Combining dense accurate lava lake and crater floor level measurements based on 1,703 satellite radar im...

The city of Goma is located in the eastern region of the Democratic Republic of Congo. With around one million inhabitants, it is built on lava flows, 15 km south of the active Nyiragongo volcano. Historically, the town was affected twice by eruptions, in 1977 and 2002 and severe destructions were reported. At that time, no volcanic risk preparedne...

Disasters related to hydrological hazards are frequent, occur worldwide, and regularly devastate many African cities. The victims are commonly among the population in precarious situations, without solid infrastructure and with incomes too low to recover from disasters. Located in the western branch of the East African Rift, and squeezed between th...

Uvira is a rapidly growing city of about 600,000 inhabitants in DR Congo. Squeezed between the shore of Lake Tanganyika and steep mountains hillslopes, and under the influence of a tropical climate, the city is familiar with flash floods. Nevertheless, the impacts of the flash flood event of April 2020 have been unprecedented in the last decades. D...

Human activity influences both the occurrence and impact of landslides in mountainous environments. Population pressure and the associated land-use changes are assumed to exacerbate landslide risk, yet there is a lack of statistical evidence to support this claim, especially in the Global South where historical records are scarce. In this work, we...

The population at risk from sudden hazards, such as volcanic eruptions, is often estimated based on the location of the residents. Crisis management tools, such as evacuation and emergency plans, are usually based on this information. Therefore, they often do not reflect over- and underpopulation in areas where the present population is different f...

Slow-moving landslides exhibit persistent but non-uniform motion at low rates which makes them exceptional natural laboratories to study the mechanisms that control the dynamics of unstable hillslopes. Here we leverage 4.5+ years of satellite-based radar and optical remote sensing data to quantify the kinematics of a slow-moving landslide in the tr...

We present here the TROPOMI SO 2 product, which is publicly available since April 2018. We describe the capabilities and limitations of the product for the monitoring of volcanic SO 2 degassing. With several examples, we illustrate the benefit of a small satellite pixel of 3.5 x 5.5 km 2 . Owing to its improved detection limit, the data can be used...

Abstract Background Nyamulagira and Nyiragongo are active volcanoes situated close to Goma (North Kivu, Democratic Republic of Congo). These volcanoes are among the most prolific sources of volcanic SO2 pollution on earth. Objective We investigated the possible spatiotemporal relationships between volcanic degassing represented by eruptive emission...

Based on a literature review and two case studies, this article presents the difficulties inherent in the main disaster risk reduction conceptual models. The method used to highlight such evidence is to compare two programs on disaster risk reduction with mainstream conceptual models. The authors participated in these programs, which were confronte...

Goma city, at the eastern border of DRCongo, is highly exposed to natural hazards, especially from Nyiragongo volcano, located directly North of it. In January 2002, the city centre of Goma was devastated by lava flows and several thousands of people were temporarily displaced. Defining and quantifying population vulnerability to natural hazards, a...

Space-borne Differential Interferometric Synthetic Aperture Radar (DInSAR) has been extensively used in the last two decades to measure ground surface deformation, providing key information for the characterization and understanding of many natural and anthropogenic processes. However, conventional DInSAR technique measures only one component of th...

(free access to the article before November 09, 2019 : https://authors.elsevier.com/a/1ZmFe,Ig4H0Uo) Active lava lakes at volcanoes can be regarded as open windows to their magmatic systems. The dynamics of such lakes may therefore provide decisive insights into deeper magmatic processes, potentially leading to fundamental theoretical implications...

Studying the causes and triggers of landslides is essential to understand the key process of hillslope evolution and the hazards they generate. Such understanding is crucial in tropical areas where landslide impacts are high and on the rise, and the dearth of accurate processes characterisation is large. Here we investigate the timing and the mecha...

Accurate precipitation data are fundamental for understanding and mitigating the disastrous effects of many natural hazards in mountainous areas. Floods and landslides, in particular, are potentially deadly events that can be mitigated with advanced warning, but accurate forecasts require timely estimation of precipitation, which is problematic in...

Cities

We processed InSAR time series of ENVISAT ASAR descending and ascending datasets and identified two new deforming areas on the northern shore of Lake Kivu, characterized by steady ground subsidence of up to ~1 cm/year over a time period of about seven years (December 2002/January 2003–March 2010). Two distinct areas can be identified: one centered...

Since its last effusive eruption in 2002, Nyiragongo has been an open-vent volcano characterized by the world's largest persistent lava lake. This lava lake provides a unique opportunity to detect pressure change in the magmatic system by analyzing its level fluctuations. We demonstrate that this information is contained in the seismic and infrasou...

Landslide hazard remains poorly characterized on regional and global scales. In the tropics in particular, the lack of knowledge on landslide hazard is in sharp contrast with the high landslide susceptibility of the region. Moreover, landslide hazard in the tropics is expected to increase in the future in response to growing demographic pressure an...

Landslides can lead to high impacts in less developed countries, particularly in tropical environments where a combination of intense rainfall, active tectonics, steep topography, and high population density can be found. However, the processes controlling landslide initiation and their evolution through time remains poorly understood. Here we show...

Along the East African Rift lie several active volcanoes characterized by different eruptive styles and magma plumbing systems. In this particular environment it is crucial to study ground deformation to better understand the interaction between tectonic, local stress and magma movements. Here we used InSAR and GPS data to measure ground displaceme...

Geological map of the Kivu region, RDC at 1/500.000 scale, based on the compilation of old exploration maps and updated using recent field data.

Magma ascent that may lead to an eruption is commonly accompanied by variations of long-period seismic activity and SO2 degassing. Space-based measurements of SO2 emission rates represent a rapidly emerging and highly convenient approach for volcano monitoring; however, combining these long term remote sensing observations with seismic data is stil...

In the Rwenzori Mountains, at the border between Uganda and the D.R. Congo, landslides frequently occur and cause fatalities and substantial damage to agricultural land and infrastructure. Up until recently, no information on the landslide characteristics, occurrence or spatial distribution was available. The use of archive inventories and field su...

Volcanic eruptions are the ultimate surface expressions of magma movements at depth. Analyzing ground deformations associated with volcanic eruptions contributes to understand the mechanisms of magma emplacement and characterize the magma plumbing systems. InSAR is a particularly well-suited tool to measure ground displacement in areas that are dif...

The western branch of the East African Rift System, in Central Africa, is a region naturally prone to landslides due to the geomorphology of the area and to the occurrence of earthquakes and heavy rainfall events. The city of Bukavu (DR Congo) is located within the Rift, on the southern shore of Lake Kivu, in a tropical environment. Little is yet k...

Climate change is reported to be ‘very likely’ associated with an increasing trend in extreme rainfall intensity over the tropics. Its impact on the timing of landslide initiation however remains poorly understood. Central Africa, located in the tropics, has repeatedly been highlighted as lacking landslide catalogs and landslide-climate studies. We...

Many cities in the Global South are known for facing an important increase in their population size. Many of them are then struggling with the sprawl of new settlements and very often urban planning and sustainable management policies are limited, if not non-existent. When those cities are set in landslide-prone environments, this situation is even...

The western branch of the East African Rift System, in Central Africa, is a region naturally prone to landslides due to the geomorphology of the area and to the occurrence of earthquakes and heavy rainfall events. The city of Bukavu (DR Congo) is located within the Rift, on the southern shore of Lake Kivu, in a tropical environment. Little is yet k...

333 volcano - tectonic earthquakes allowed to analyze the attenuation of the coda waves by the Single Scattering model in the Virunga region at the east of Democratic Republic of Congo. A high attenuation obtained by the quality factor or of these waves illustrates a heterogeneous area dominated by scattering due to the presence of the magma in fra...

Five periods characterize the temporal variation of the quality factor of seismic coda waves attenuation () at 9 Hz and lapsed time of 30 seconds, before the Nyamulagira eruption of 6 November 2011 in the Virunga volcanic region of eastern Democratic Republic of Congo. The period I (January - March 2011) was characterized by low attenuation. It gro...

This study evaluates the vulnerability facing the lava flows of Nyiragongo volcano, of the water and electricity distribution networks in the Goma city (DRCongo). The Nyiragongo volcano represents a permanent threat for this city, because of its proximity (approximately 18km to the north) and the direction followed by its lava flows during two know...

The Kivu rift is located in the bordering region of theDemocratic Republic of Congo and Rwanda, in the western branch of the East African rift. Here, the active volcanoes Nyamulagira (the most active in Africa) and Nyiragongo (host to the largest persistent lava lake on Earth) threaten the city of Goma and neighboring agglomerations, and destructiv...

We present an overview of the installation, operation, and initial results of the 15-station KivuGNet (Kivu Geodetic Network) in the Kivu Region, Central Africa. The network serves primarily as a research and monitoring tool for active volcanic, earthquake, and plate boundary processes in the region. Continuous operation of in-situ measurement netw...

The Virunga Volcanic Province (VVP) represents the most active zone of volcanism in the western branch of the East African Rift System. While the VVP’s two historically active volcanoes, Nyamulagira and Nyiragongo, have built scoria cones and lava flows in the adjacent lava fields, several small phreatomagmatic eruptive centers lie along Lake Kivu’...

In the frame of the Belgian GeoRisCA multi-risk assessment project focusing on the Kivu and northern Tanganyika rift region in Central Africa, a new probabilistic seismic hazard assessment has been performed for the Kivu rift segment in the central part of the western branch of the East African rift system. As the geological and tectonic setting of...

The study of rift basin’s morphology can provide good insights into geological features influencing the development of rift valleys and the distribution of volcanism. The Kivu rift segment represents the central section of the western branch of the East African Rift and displays morphological characteristics contrasting with other rift segments. Di...

In central Africa, a combination of several types of major geo-hazards threatens the highly populated area centred on the Lake Kivu Basin and the Virunga Volcanic Province. Contributing to Disaster Risk Reduction (DRR) policies not only go through hazards mechanisms analysis, but also through vulnerability assessment. This paper stresses the method...

The western branch of the East African Rift is threatened by a rare combination of several types of geohazards, while it is also one of the most densely populated regions of Africa. These geohazards can globally be classified as seismic, volcanic and landslide hazards. Landslides are possibly the most important geohazard in terms of recurring impac...

Volcanic cone fields are generally made up of tens to hundreds of monogenetic cones, sometimes related to larger polygenetic edifices, which can exhibit a wide range of morphologies and degrees of preservation. The Virunga Volcanic Province (VVP) developed itself in a transfer zone which separates two rift segments (i.e. Edward and Kivu rift) withi...

The western branch of the East African Rift System, in Central Africa, is characterized by the presence of several geohazards: earthquakes, volcanoes, and landslides. Every year, landslides cause fatalities, structural and functional damage to infrastructure and private properties with serious disruptions of the organization of societies and severe...

The Rift flanks west of Lake Kivu (DRC) are one of the Congolese regions most affected by fatal landslides. However, information on the distribution of these processes and their impact on society is still lacking. Here we present a first regional landslide inventory and the associated elements at risk. The inventory was conducted in an area of 5,70...

The region of interest, stretching along the western branch of the EAR from Lake Tanganyika to the Rwenzori Mountains, is threatened by a rare combination of several types of geohazards, while it is also one of the most densely populated region of Africa. Landslides are possibly the most important geohazard in terms of recurring impact on the popul...

A summit and upper flank eruption occurred at Nyamulagira volcano, Democratic Republic of Congo, from 2–27 January 2010. Eruptions at Nyamulagira during 1996–2010 occurred from eruptive fissures on the upper flanks or within the summit caldera and were distributed along the ~N155E rift zone, whereas the 2011–2012 eruption occurred ~12 km ENE of the...