Examination of the Feasibility of Area-Specific Criteria of Special Weather Report by Estimation of the Threshold Value of Disaster-Causing Strong Winds

Abstract

Strong winds are one of the several factors contributing to natural disasters. Although in recent years, the intensity and frequency of strong winds has decreased, different areas are differently affected by such winds; these winds still have the potential to cause adverse impacts on life and property. In Korea, strong winds are also responsible for the incidence of increased number of accidents and forest fires. Therefore, in this study, relationship between wind speed and damage was analyzed, and the threshold value of damage-causing wind speed was estimated. We first analyzed the relationship between wind speed and damage occurrences based on the daily maximum wind speed and daily maximum instantaneous wind speed data, and data on damage related to strong winds. Second, we examined the validity regarding the regional segmentation of the Korean criteria of special weather report for strong winds using the critical success index and cumulative percentile distributions to estimate the damage-causing threshold value for each region. We found that damage resulting from very strong wind speeds in Korea had not occurred in recent times. In addition, considerable damage had occurred because of low-speed wind compared to the current criteria for high wind advisory. However, the incidence of damage was higher when wind speed was stronger than the current criteria for high wind advisory. Based on threshold estimation, the study areas were categorized into areas with high threshold values (coastal, mountainous, and island), and those with low threshold values (inland areas). A notable difference was observed between the threshold values of the two categories of areas. This necessitated the regional segmentation of the criteria of special weather report on strong winds.