Systemic Uncertainties and Decision Support Applications in Regional Seismic Loss Analyses

A number of tools and advancements have been developed over the course of the last decade for public use in regional seismic disaster planning. This paper addresses some of the considerations and approaches that influence state-of-theart regional seismic loss assessments and risk management, with particular emphasis on approaches applied to areas having potentially high consequence but low probability seismic hazards in the United States. The various components of regional seismic loss assessment are synthesized within a GIS-based framework, including the aggregation and propagation of uncertainties inherent in the analysis. The threat posed by ground shaking and ground failure hazard effects is estimated and mapped onto high resolution point-wise building stock and bridge inventory assets. Inventory vulnerability is assigned based on structural classifications of construction materials, together with general system configurations and lateral resisting system types. Likelihood of damage to the built environment is then determined by the combination of the hazard and vulnerability for each building and bridge, and social and economic consequences are projected based on correlation with descriptions of physical damage levels, both in terms of expected values, and dispersions of the aggregate regional analysis output. Decision support algorithms are also discussed, which leverage the high resolution of the regional analysis output to focus mitigation planning and capital investment on particularly sensitive and influential assets within study regions.