Environmental dynamics of western Rwanda (E-DOOR)
This integrated study will identify the key environmental dynamics of the volcanic region of western Rwanda. The region of interest exhibits complex interactions between four systems:
- The Nyiragongo volcano and its hazards;
- The Lake Kivu ecosystem and its methane reservoir exploitation;
- The biodiversity of the volcanic soil;
- The social system of the nearby communities.
These interactions are poorly known, yet they likely have important interaction signals that inform land-use management, human health, ecosystem management and restoration in a social-ecological framework. The study approaches these dynamics in an integrated approach, applying different methodologies and fields (physical volcanology, ecology and social science) in a transdisciplinary approach to provide integrated answers to the Rwandan Government based on scientific developments.
The challenges of the population of Western Rwanda, especially in the city of Gisenyi (~90,000 habitants) are multiple: from volcanic hazards including lava flows, earthquakes and volcanic plumes, to the danger of a massive degassing of the lake (gas-driven limnic eruption) that would cause asphyxiation and/or the spread of podoconiosis, a severe and debilitating swelling of the lower limbs.
The study will use different but complementary approaches: theoretical and numerical modelling in physical volcanology; data analysis of physico-chemical and phytoplankton assemblages in Lake Kivu; a study of surrounding soils; and a social-ecological analysis of the relationship between human and environmental health in the region. This project will provide scientific information with specific outcomes that are useful to the Rwandan governmental agencies responsible for the environment (Ministry of Environment) and health (Ministry of Health).
Key information
Duration
2021-2024
IGCP Theme
Earth Resources
Project Leader
Professor of Geophysics, ICTP-East African Institute for Fundamental Research, Rwanda
Highlights
Health and volcanoes in Western Rwanda
30 November - 1 December 2023
The IGCP E-DOOR project team organized a two-day meeting in Kigali with health care workers and civil society from western Rwanda, and governmental agencies. They discussed health issues and their possible links with the volcanic environment of the region while focusing on gas emissions from Nyiragongo and andisols (volcanic soils). This initiative was a joint collaboration between the geophysics pole of the ICTP-East African Institute for Fundamental Research and the Center of Excellence in Biodiversity and Natural Resource Management (CoEB), both hosted by the the University of Rwanda (UR).
The event aimed to share information with and between partners, governmental agencies, civil society and health workers, sensitizing them to the health impacts of the volcanic activity during a volcanic crisis but also in quiescent periods and long-term.
E-DOOR Report
"Nykishu: Interactions between the Nyiragongo volcano, Lake Kivu, its aquatic ecoSystem and the human system: an integrated knowledge approach".
The E-DOOR project team released the above report in January 2023, with three main facets:
- Potential effects of the topography and bathymetry on a laterally propagating dike under Lake Kivu (analytical and numerical approach).
- Analysis of physico-chemical and phytoplankton assemblage data in Lake Kivu over the period 2019-2022, which includes the volcanic crisis of May 2021.
- Quantitative analysis of the survey conducted in August 2022 on the social, environmental, and economic impact of the last eruption.
Background
Nyiragongo is an active strato-volcano, part of the Virunga volcanic chain, located in the western branch of the East African Rift, in the east of the Democratic Republic of Congo (DRC), where it borders Rwanda and its district of Rubavu. The volcano culminates at 3,470 m above the city of Goma in DRC, a city of 1,100,000 inhabitants, and Lake Kivu. Nyiragongo erupted in 1884, in 1977 and in 2002, killing several hundreds of people each time. The most recent eruption occurred in May 2021, killing 100 people and displacing up to 400,000. Eruptions from the Nyiragongo volcano are characterized by:
- High-speed travelling lava flows of low viscosity
- Daily tons of gas releases via its lava lake and plumes
- Radial fissures south east of the summit and along NE-SW faulting zone extending as far as Lake Kivu (Sawyer et al., 2008; Bobrowski et al., 2015; Fisher et al., 2019)
Lake Kivu, covering a surface area of 2,700 km2, is Rwanda's largest lake and is shared with the DRC and is the sixth largest in Africa. The lake itself represents an even greater potential danger than Mount Nyiragongo. It contains 300 cubic kilometres of dissolved carbon dioxide and 60 cubic kilometres of methane, mixed with toxic hydrogen sulphide, gases which could be released explosively during a so-called gas-driven limnic eruption (Schmid et al., 2005; Boehrer et al., 2019). Such an eruption, especially of CO2, could asphyxiate all living species around Lake Kivu on the Congolese and Rwandan side. It would cause thousands of deaths in both countries. At the same time, Lake Kivu constitutes a major economic resource. Pumping methane from Lake Kivu has existed on a small scale for decades for use as a source of energy. But efforts have seriously stepped up since KivuWatt, run by London-based ContourGlobal, began operations in 2016 in Rwanda. The $200 million project currently supplies 26 MW of electrical power, and it has a contract to increase it to 100 MW. Recently, another player, GasMeth Energy also received approval from the Rwandan Mining Board (RMB) and the Rwandan Defence Force (RDF) for processing Compressed Natural Gas (CNG). This will significantly add to Rwanda's baseline installed grid capacity of approximately 200 MW.
However, even if the total gas pressure at any depth in the lake is today at most half the hydrostatic pressure at the same depth, conditions preventing bubbling and gas exsolution, the local and scientific communities today are extremely divided on the impact and safety of gas extraction, which could erode the water column stability (Bärenbold et al., 2020; Bolson et al., 2021; Schmid, 2021). More than two 2 million people today live around Lake Kivu and are highly dependent on the lake for their livelihoods. The combination of Lake Kivu's monetary value, its potential explosive capacity, and the wide range of opinions on how best to deal with it, thus calls for more scientific work on the lake stability through both monitoring and modelling (e.g. Folch et al., 2017).
Volcanic soils in general have excellent physical properties that make them highly desirable for biodiversity and a wide range of land uses. Yet, there is a very wide range of chemical limitations in volcanic soils, most of which are nutrient deficiencies. While the soil ecosystem in Rwanda western province derives its main geochemical and petrological characteristic from its volcanic origin, its substrate today is marked by many factors such as topography, weathering, climate change and anthropogenic factors from land uses such as agriculture and agroforestry. These fingerprints are still waiting to be characterized in Rwanda western province in a context, where agriculture is one of the two means of subsistence of the communities together with fishing and when quality soil is a key to good crop yielding.
This project was developed with the generous financial support of the Jeju Province Development Co. (JPDC).
