Changes in the extreme daily rainfall in South Korea



This paper examines the usefulness of the non-stationary generalized extreme value (GEV) distribution in modelling extreme rainfall. We modelled the annual maxima of daily (AMP1) and 2-day (AMP2) rainfall data observed during the summer rainy season, dating up to 2007 in 28 stations in South Korea. We fitted the GEV distribution to the data for each location. The location parameter of the GEV distribution was formulated as a function of time to explore the temporal trends in maximum precipitation over the course of climatic change and to predict future behaviours. We found evidence of non-stationarity in the form of increasing trends for six stations from AMP1 and for five stations from AMP2. This trend is consistent with the results from a regional climate model derived by the A1B emission forcing of IPCC AR4. The stationary Gumbel distribution provided a good fit to the AMP1 data for 18 stations and to the AMP2 data for 15 stations. We quantified the changes in extreme rainfall for each station; the return levels and their 95% confidence intervals for various return periods are provided. Copyright © 2010 Royal Meteorological Society