Seismic Hazard and Risk Analysis Using OpenQuake and Seismic Scenario Toolbox:A Comparative Study

The evaluation of the potential impact of strong seismic events shortly after their occurrence is a critical step to organizing emergency response and consequently minimize the adverse effects of earthquakes. This study describes a methodology to combine the publicly available information and the open-source software OpenQuake and Seismic Scenario Toolbox for the assessment of damage and losses. Mainly two analyses were performed depending on the research area and the different sets of input data provided example exposure model, fragility and vulnerability model, etc. One analysis was performed on Modena province and another on 5 selected municipalities. This approach is mainly employed to estimate the structural damage considering the 2012 Magnitude 5.6 Emilia-Romagna (Italy) earthquake and the aggregated economic loss. The analytical fragility and vulnerability were derived using nonlinear time-history analyses using VMTK Toolkit. Other Fragility Models have also been developed based on the data obtained from numerical analysis on the buildings depending on year of construction and the number of stories. A finite rupture definition was provided, along with the selected GMPE. Also set of ground-motion fields is generated by providing the user-defined recordings (INGV). Subsequently, the Scenario Damage Distribution calculator computes for each asset the fraction of buildings in each damage state using the fragility models. The study, allows to predict damage scenarios by analyzing recordings, calculating a series of ground motion intensity measures, and assessing the expected potential damage, on a set of residential and other building types, making it possible to generate shake-maps, using different IMs. The analysis has been run through OQ Engine and Seismic Scenario Toolbox. Several comparisons drawn between the estimated damage/losses obtained through OQ Engine and the damage/losses through SDT, between the GMFs generated by OQ Engine and the INGV recordings.