Publicaties

Smets, B.,  Michellier, C.,  d'Oreye, N. & Kervyn, F. 2017. ‘New Perspectives offered by SfM-MVS Photogrammetry for Volcano Monitoring and Risk Mapping in the Virunga Volcanic Province (D.R.Congo)’. Disasters and resilience in the 21th Century, Multidisciplinary Workshop of the Royal Academy for Overseas Sciences. Book of abstracts.

Conference abstract

Nyiragongo volcano, in the Congolese part of the Virunga Volcanic Province, is among the most active volcanoes on Earth and probably one of the most hazardous volcanoes of Africa. Its last flank eruption, in January 2002, was a disaster with tens of persons killed and hundreds injured. This eruption destroyed part of the city of Goma (~800 000 inhabitants nowadays) and triggered an important humanitarian and socio-economic crisis. In the present work, we describe the most recent investigations performed on Nyiragongo and its vicinity, in order to monitor its intense eruptive activity and map the threatened areas using Structure from Motion – Multi-View Stereo (SfM-MVS) photogrammetry. SfM-MVS represents the most recent advance in terms of digital topographic and imaging survey, and its application in the geosciences and risk assessment is increasing exponentially. In the studied area, this technique allows the acquisition of very-high spatial resolution (i.e., < 1 metre) data and, thanks to its low cost, the easy repetition of the survey whenever time-series are needed. Multi-view time-lapse camera systems are used to measure the level variations and surface motion of the Nyiragongo lava lake. These results, combined with shadow measurements on radar satellite imagery, provide quantitative information on the dynamics of the lava lake. Helicopter flights and drone surveys are used to model the Nyiragongo crater and measure volume changes and ground deformation associated with the lava lake activity. All these results on Nyiragongo provide crucial information on pressure changes in the upper volcanic plumbing system and offer new perspectives for the early detection of hazardous flank eruptions. Helicopter flights and SfM-MVS are also used to produce very-high resolution digital surface models and orthophotos over the city of Goma. These datasets provide the opportunity to better characterize, at an unprecedented level of detail, the urban infrastructures (roads, houses, strategic buildings, etc.) threatened by lava flows, map hazardous areas of diffuse CO2 degassing (locally called “mazuku”) and study the probability of invasion by lava flows within the city.