A simplified holistic framework to understand the sensitivity of seismic risk to hazard variability

Seismic risk models are essential for assessing earthquake impacts, yet frequent hazard model updates create challenges for understanding their effects on risk estimates. This paper presents a simplified holistic framework to evaluate seismic risk sensitivity to hazard variability. Using two versions of the European Seismic Hazard Model, hazard variability is analyzed, revealing non-uniform changes across different return periods and shifts in the slope of the hazard curves. Statistical analyses show correlation of the two versions but also notable data spread, and thus alternative techniques to tighten the relations of the compared variables are discussed. The variability introduced in risk estimates is found increased compared to that of the hazard input, with the effects of the non-uniform variation of hazard across different periods being quite noticeable on the risk change. Also, risk sensitivity is amplified with increasing hazard and reduced vulnerability. Finally, the framework extends its applicability by proposing a practical approach for stakeholders, to prepare for potential future updates of regional hazard models and better inform risk management strategies.