저기압 통과 시 호우사례별 레이더 강우강도와 지상강수량 비교

Abstract

The Korean Peninsula located in the mid-latitudes is under the influence of westerlies. The low pressure trough and the low-pressure approaching from south-west often pass through the Korean Peninsula. Jeju Island, positioned to the southwest of the Korean Peninsula, is the first to be affected by the low pressure trough and/or the low-pressure. This study was performed to analyze the average annual rainfall for 1981-2010 normal and rainfall and the issuing situations of the special weather reports for the last five years (2011-2015) in Jeju Island. In this study, we try to investigate the relationship between the predicted rainfall, the estimated rainfall by weather radar echo and the observed rainfall and to understand the characteristics of local rainfall on Jeju Island when the special weather reports were issued. Jeju Island is one of the pluvial sites in Korea. Compared with normals, the average annual rainfall for the last five years were increased and the number of rainy days were decreased in Jeju Island. During the last five years, special weather reports for heavy rain were issued totally 288 times and were most frequently issued at a mountainous area. Based on the data of actual rainfall during the period of special heavy rain reports, it could be concluded that the predicted rainfall were overestimated in the case of the actual rainfall of below 50 mm, while those were underestimated in the case of above 100 mm. In the eastern part of Jeju Island, there was a relatively good relationship between the predicted and actual rainfalls. When the special heavy rain reports were issued, correlation between the predicted and actual rainfalls was very low in Jeju Island. It could be found that the very weak correlation between the actual rainfall and the estimated rainfall by radar echo in this study. Therefore, it is necessary to improve the conventional equation, Z = 200 R^(1.6), by considering the geographic features of Jeju Island in order to exactly estimate the rainfall by using weather radar echo.