Publications

Barette, F.,  Michellier, C.,  Mossoux, S.,  Poppe, S.,  Smets, B.,  Wolff, E.,  Kervyn, F. & Kervyn, M. 2017. ‘Assessing lava flow risk at Nyiragongo volcano, DR Congo. Part 2: Lava flowhazard map’. IAVCEI Scientific Assembly 2017. Book of abstracts.

Conference abstract

Nyiragongo volcano, located at the boundary between the Democratic Republic of Congo and Rwanda, is characterised by intra-crater lava lake activity interrupted by flank eruptions. Over the last 120 years, two disastrous flank eruptions occurred at Nyiragongo volcano, in 1977 and 2002. In 2002, two lava flows inundated the denselypopulated city of Goma, destroying about 10% of the city, one third of the airport runway and most of the business centre. Between 300,000 and 400,000 people evacuated the city and the eruption caused several tens of fatalities. Within the framework of the GeoRisCA project, we computed a new lava flow hazard map for Nyiragongo volcano. The vent opening susceptibility at Nyiragongo volcano was assessed with the QGIS for Volcanic Susceptibility (QVAST) plugin, using historical and non-historical eruptive fissures and vents as structural elements. Distinct probability density functions were calculated for these structural elements, and these were subsequently combined to derive the spatial probability of future vent opening along Nyiragongo flanks. The lava flow hazard was computed using the Quantum-Lava Hazard Assessment (Q-LavHA) model using a high accuracy and up-to-date TanDEM-X derived Digital Elevation Model (DEM) as topographic base. The model parameters were calibrated by simulating the 2002 lava flow of Nyiragongo volcano, using the 30 m SRTM DEM. The length of the historical lava flows was analysed to statistically constrain the terminal lava flow length of the simulations. A corrective factor based on the calibration of the model was used to account for the impact of the DEM resolution on the simulated lava flow length. Our results indicate that the probability of vent opening is very high on the southern flank of Nyiragongo volcano, along the north - south oriented fissure system. The lava flow hazard is high on the southern flank of Nyiragongo volcano, and particularly in the western and eastern part of Goma. The latter was already destroyed during the 2002 eruption of Nyiragongo volcano. Our results, combined with the assessment of the exposure and vulnerability of the population and built elements (Part 1), shows that the lava flow risk is particularly high in the eastern part of Goma.