Author(s): Jeseung Oh; Chiyoung Kim; Won Kim
Linked Author(s): Won Kim
Keywords: Shift; Trend; Rainfall analysis; Localized heavy rainfall
Abstract: This study is aiming to analyze the characteristics of rainfall variation, especially the shift at the time of 1998 in Korea when localized heavy rainfall during short term frequently occurred. The rainfall data observed at 61 sites were preprocessed to the number of rainfall exceeding a certain value and to maximum hourly, daily and 10 minutely rainfall in each year. The tests are computed with the methods for trend and fluctuation provided in WCDMPVol. 45 issued by WMO in 2000. As the result, the analysis of excess number for each considered time period shows that change in all durations is statistically significant. This means that the number of rainfall above certain amounts in each duration have increased more than before. This trend of shift is observed in the analysis using the maximum rainfall as well. There are 3 sites where the shift was checked in the only maximum rainfall for 10 minutes. However, in terms of the hourly and daily maximum rainfall in 30 sites out of 61, the shift is significant. This study shows that the amounts of short term rainfall and the number of heavy rainfall have increased since 1998 in Korea.