APPLICATION OF DEAGGREGATION OF SPATIAL PROBABILISTIC SEISMIC HAZARD FOR DISASTER PREPAREDNESS

For regional disaster prevention, it is important to understand the area of occurrence of strong ground motion and its occurrence probability. The spatial probabilistic seismic hazard analysis (SPSHA) proposed by the authors can provide this information. In SPSHA, the results are expressed as a relation between the area where a given seismic intensity is generated and the exceedance probability. Results obtained from such a probabilistic approach include the effects of various seismic sources. Therefore, to efficiently describe an earthquake scenario for regional earthquake countermeasures, it is necessary to understand the impact of each earthquake source. In this study, we propose a seismic hazard deaggregation for SPSHA, and present a method for quantitatively understanding the earthquakes that affect the target region. As a practical application, SPSHA is conducted for Kanagawa prefecture in Japan. We conducted seismic hazard deaggregation for whole and sub-area, and discussed the differences in dominant earthquakes among areas and the use of such information in disaster prevention.