Advantages of using sensitivity analysis in seismic hazard assessment: A case study of sites in southern and eastern Spain

This article presents a sensitivity analysis of the different nodes of a logic tree that was carried out using the seismic hazard results obtained with the zoning methodology (Cornell, 1968) and computed with the EQRISK program (McGuire, 1976). The aim of this sensitivity analysis is to identify the input parameters that have the greatest impact on hazard assessment and its uncertainty. The research findings from the study of these parameters may serve as a useful guide to facilitate further research studies on seismic hazard evaluations because they allow us to identify parameters that have little or no effect on seismic hazard results and the parameters that have great effects on them. In this way, using the results obtained, we discovered that the nodes related to the relation used to convert intensity to peak ground acceleration, the area source model, and the ground-motion relation have the highest sensitivity. Even so, it should be noted that the degree of sensitivity of the logic-tree nodes depends on the study site. Finally, the advantage of using sensitivity analysis in the reevaluation of seismic hazard is that it provides a useful tool for identifying the most important parameters for seismic hazard analysis. A meticulous study of these parameters will lead to the reduction of uncertainties in future assessments.