The scale of typhoon RUSA

Abstract. In August 2002, Typhoon RUSA hit Korea with severe gale and storm, causing extensive damage throughout the whole country and especially in the Gangneung area. Even on a single day, Typhoon RUSA recorded up to 879.5 mm of rainfall in the Gangneung area. Quantitative and qualitative analyses of the scale of Typhoon RUSA are performed in this study. Most of the inland affected by RUSA in the Korean Peninsula recorded heavy rainfall, equivalent to a return period of more than 200 years. Especially, rainfall of 24 h duration exceeded the maxima observed so far. Although areal rainfall showed a rapidly decreasing trend with increasing area, it reached 96 percent of the existing PMP within a 2000 km² area and recorded the maximum observed value of Korea according to a DAD analysis of rainfall. Re-estimated PMP values obtained from a hydro-meteorological approach compared with existing PMP estimates revealed a discrepancy between the two values, which showed that re-estimated PMP values of 12 to 24 h duration within 2000 km² exceeded the existing PMP estimates of Korea. Therefore, modification of the existing PMP is required, which is used as a design hydrological variable of hydraulic structure.