Effect of RCM Temporal Resolution on Estimating Future IDF Curves

Abstract

Recent domestic researches on the future design rainfall have been conducted by applying various temporal downscaling techniques based on daily temporal resolution data produced from Regional Climate Model (RCM) provided by Korea Meterological Administration (KMA) and CORDEX. However, no matter what temporal downscaling techniques are applied, many assumptions are needed in the process of estimating the design rainfall for sub-daily duration from daily rainfall time series. In this study, we investigated the effect of RCM temporal resolution on the estimation of future IDF curves. For this purpose, temporal resolution 3-hour and 24-hour rainfall data were constructed using observed hourly rainfall time series of KMA of Busan station. And, the derived IDF curves were compared with the IDF curve derived from temporal resolution 1-hour rainfall time series, respectively. As a result, it was confirmed that the IDF curve derived from the temporal resolution 3-hour rainfall data reproduces the IDF curve derived from the observed hourly rainfall time series better. Also, future IDF curves were derived from temporal resolution 3-hour future rainfall time series that dynamically downscaled at Busan station using RCM (WRF), general climate model HadGEM2-AO driven by RCP 8.5 scenario. Finally, the effect of RCM's temporal resolution on the estimation of future IDF curves was analyzed by comparing with the future IDF curve derived from temporal resolution 3-hour and 24-hour future rainfall time series. Keywords: Climate Change, IDF Curve, RCM, Temporal Resolution