A study on risk assessment of complex disasters in Busan coast

In the vicinity of the coast, there is a risk of complex disasters in which inland flooding, wave overtopping, storm surge, and tsunami occur simultaneously. In order to prepare for such complex disasters, it is necessary to set priorities for disaster preparedness through risk assessment and establish countermeasures. In this study, risk assessment is carried out targeting on Marine city, Centum city, and Millak waterside parks in Busan, where complex disasters have occurred or are likely to occur. For risk assessment, inundation prediction map constructed by the Ministry of Public Administration and Security in consideration of sea level rise, rainfall and storm surge scenarios and authorized data on social and economic risk factors were collected. The socioeconomic risk factors selected are population, basements, buildings, sidewalks, and roads, and the risk criteria for damage targets are set for each risk factors. And it was assessed considering the maximum inundation depth and maximum flow velocity of the inundation prediction map. Weights for each factor were derived through expert questionnaires. The risk assessment index that was finally evaluated by calculating the risk index for each element and applying weights was expressed as a risk map by different colors into four levels of attention, caution, alert and danger.