PARATUS case-study Bucharest. A new seismic risk assessment model.

Bucharest can be considered Europe's most endangered capitals due to earthquakes. Intermediate-depth events occurring in the Vrancea Area, with magnitudes greater than 7, can significantly affect Bucharest. In the XX^th century, the city experienced two major damaging earthquakes: in 1940 and 1977. But lessons were not fully learned. The number of vulnerable buildings is highly considerable: over 30% are built before 1963 (of which 22%, before 1941). The increased complexity of our society and new challenges among which climate change, pandemics and globalization are new problems to address. In this context, multi-hazard and multi-risk analyses are more than ever necessary.

If the 1977 earthquake generated numerous research with the aim of quantifying the vulnerability of the building stock and improving seismic design, social vulnerability to seismic risk was addressed only after 2000 by the Risk Research Center, University of Bucharest, based on a repeated spatial vulnerability assessment at city-level. Applying the additive approach of the multi-criteria and decision-making analysis in GIS, the spatial social vulnerability was identified by indicators of social and economic metrics, among which social capital and inequality, distance analysis, and on empirical taxonomies: gender, age, social status, ethnicity, type of housing, etc., based on 1992, 2002 and 2011 census data. Calibrating results using remote sensing and social surveys, helped identify vulnerable hotspots and the dynamic of social differences at city level.  

Superimposed on these detailed vulnerability maps for Bucharest based on computed vulnerability indices, a critical decision-making tool for safe access routes in the emergency intervention was developed supported by large sets of traffic and network data, time-dependent analysis, and seismic loss-estimations. This tool, called Network-Risk, uses a state-of-the-art network analysis methodology embedded in GIS, with the potential of integrating live traffic data.

All these topics will be continued in the recently started PARATUS European Project, where Bucharest is a case-study area. In our presentation, we talk about the new data and procedures that we consider for seismic risk assessment (among which new exposure data from a recent census or retrieved from remote sensing missions using deep learning, new data collecting procedures, vulnerability models and city-scale ShakeMap development) and which are the challenges – especially in the nowadays context.