Understanding and assessing georisks in Central Africa: a prerequisite to design efficient decision support tools towards a better resilience
The densely populated area extended from the North Kivu province in Democratic Republic of the Congo (DRC) to North Burundi and East Rwanda is vulnerable to several geohazards, such as landslides triggered by geodynamical processes (climate, seismicity, volcanism) and possibly worsen by anthropic actions. Located in the East African rift valley, the region is also characterized by a strong seismicity, with an increasing number of people and infrastructures exposed. In addition, east DRC hosts the two most active African volcanoes: Nyiragongo and Nyamulagira. Their activity can have serious impacts, as in 2002 when Nyiragongo directly endangers the ~800.000 inhabitants of Goma city, located ~15 km to the south. Linked to passive volcanic degassing, SO2 and CO2 discharge may also increase the population vulnerability. GeoRisCA is a project, funded by the Belgian scientific policy, which aims at studying the geo risks in this region (DRC, Rwanda, Burundi) in order to support regional and local risk management. A key contribution of GeoRisCA is to work together with the national and local institutions on assessing and outlining the vulnerabilities by taking into account exposure to perturbations and adaptive capacity or resilience of the systems. On one hand, the exposure is identified as the potential degree of loss of a given element or set of elements at risk; i.e. the susceptibility of people, infrastructures and buildings with respect to a hazard. On the other hand, the resilience of the individual, the household, the community, is its adaptive capacity to absorb disturbance and reorganize into a fully functioning system by anticipation, response, adaptation and recovery. It focuses mainly on land use and on socio economic and demographic factors that increase or attenuate the impacts of hazards, and evolve with time (e.g. improved education, increased income, denser social networks and evolution of coping mechanisms) The output of GeoRisCA will be a comprehensive but simple methodology for reliable geo risks measurement and mapping, designed as decision supporting tools for existing disasters preparedness and mitigation institutions.