Development of a Method for National Risk Assessment Based on Heavy Rain-induced Multi-Hazard Scenarios

Abstract

In order to estimate the multi-hazards affecting the Korean peninsula, a National Risk Assessment (NRA) method is developed and applied to the regions of Incheon and Gangwon provinces using multi-hazard scenarios. National risk can be assessed on the basis of likelihood (the probability of occurrence) of a hazard and its impact (the degree of damage caused). Likelihood is assessed by statistically analyzing historical patterns of heavy rainfalls in ranges of 50- and 500-year return periods that may occur within the next five years. Impact is assessed by applying the developed fragility model based on historical damage data and expert surveys. The final national risk is assessed in the form of a 5 × 5 matrix by applying the assessment results of both likelihood and impact. The NRA method developed in this study can be utilized as a scientific basis for analyzing multi-hazards and establishing countermeasures for risk factors in the near future. Keywords: National Risk Assessment, Likelihood, Multi-Hazard Scenario, Impact