手法を比較

	Deterministic Seismic Hazard Analysis	Seismic Hazard Deaggregation
分野	Disaster Studies	Disaster Studies
系統	Process / pipeline	Process / pipeline
提唱年	1990	1999
提唱者	Leon Reiter (codification); classical engineering-seismology practice	Paolo Bazzurro & C. Allin Cornell
種類	Scenario-based ground-motion estimation pipeline	Post-processing pipeline that decomposes probabilistic hazard into contributing scenarios
原典	Reiter, L. (1990). Earthquake Hazard Analysis: Issues and Insights. New York: Columbia University Press. ISBN: 9780231065344	Bazzurro, P., & Cornell, C. A. (1999). Disaggregation of Seismic Hazard. Bulletin of the Seismological Society of America, 89(2), 501-520.
別名	DSHA, Scenario Earthquake Analysis, Maximum Credible Earthquake Analysis, Deterministic Ground-Motion Estimation	Seismic Hazard Disaggregation, PSHA Disaggregation, Hazard Deaggregation, Controlling Earthquake Deaggregation
関連	3	3
概要	Deterministic Seismic Hazard Analysis (DSHA) estimates the ground motion a site would experience from a specific, postulated earthquake scenario rather than from the full probabilistic aggregation of all possible earthquakes. The analyst identifies the seismic sources capable of affecting the site, assigns each a maximum magnitude and a closest distance, and then asks what shaking the most demanding of these scenarios would produce. Leon Reiter's 1990 text codified the four-step DSHA procedure that remains the textbook reference, situating it alongside the probabilistic framework that Cornell introduced in 1968. The output is typically a single design ground motion or response spectrum, often computed at the median or median-plus-one-standard-deviation level. DSHA answers the question 'what is the worst shaking a credible earthquake could deliver here?' rather than 'how often is a given shaking level exceeded?'. It remains central to critical-facility design, scenario emergency planning, and as a deterministic cap on probabilistic results.	Seismic hazard deaggregation (also spelled disaggregation) is the post-processing step that opens up a probabilistic seismic hazard result to reveal which earthquakes actually drive it. A probabilistic seismic hazard analysis (PSHA) integrates over all magnitudes, distances, and ground-motion variability to return a single mean rate at which a ground-motion level is exceeded, but in doing so it loses sight of the individual scenarios. Bazzurro and Cornell's 1999 paper formalized how to invert this aggregation, expressing the contribution to the exceedance rate as a probability distribution over magnitude, distance, and epsilon — the number of standard deviations a target motion sits above the median prediction. The result identifies the controlling earthquake: the magnitude-distance-epsilon combination most responsible for the hazard at a chosen return period. This deaggregation is what lets engineers select realistic scenario earthquakes and ground-motion records for design and analysis. It bridges the probabilistic and deterministic worlds by naming the events hidden inside the integral.