Climate Change Adaptation to Extreme Rainfall Events on a Local Scale in Namyangju, South Korea

Preparing for the impacts of climate change, especially extreme rainfall events, is not a "one size fits all" process. Exhaustive case studies must be reported to understand the impact of climate change in a local area. However, there have been some difficulties in presenting all procedures used to derive the impact of climate change. Therefore, the current study presents a local case study of how a local small basin is prepared to mitigate the effects of climate change on extreme rainfall events. From the case study, the full procedure to produce an intensity-duration-frequency (IDF) curve regarding a number of future global circulation model (GCM) daily precipitation scenarios is described in detail. The major portion of this work is focused on simply estimating extreme rainfall intensity with an IDF curve considering climate change scenarios from a GCM ensemble. From all available GCMs (19), the IDF ensemble is estimated with the following procedure: (1) daily GCM outputs obtained from the grid point that is closest to the target area were bias-corrected with gamma distribution after checking the suitability of the distribution model; (2) the bias-corrected daily precipitation data were downscaled; and (3) the IDF curves for the future scenarios were estimated and an ensemble was used to produce the final IDF curve. The result indicates that the IDF curve of future scenarios effectively inherits the behaviors of the original GCM daily precipitation outputs. The future IDF estimate will be employed to prepare for the effects of future climate change on extreme rainfall events on a local scale. (c) 2020 American Society of Civil Engineers.