Issues and Challenges in Seismic Risk Evaluation and its Uncertainty Reduction for the Nankai Trough Earthquake

Abstract

The research project titled "Promotion of observation and research plan of earthquakes and volcanos for contributing to mitigation of disasters" was initiated in 2014, and the preliminary study was performed in FY2015. As a preliminary study, a framework for seismic risk evaluation with the consideration of epistemic uncertainty was developed. The secondary study was performed in FY2016, and the methodology for the seismic risk evaluation is improved in 3 parts: i.e., the revision in GMPE models considering the saturation effect, the revision in loss model in terms of the fatalities as well as the direct losses in buildings, and the extension of target sites to entire Kochi and Osaka prefectures. The results of preliminary and secondary studies suggest that the epistemic uncertainty in GMPEs is most sensitive to the overall uncertainty of seismic risk.