Future Changes in Watershed-scale Rainfall Characteristics: Application of AGCM20 to the Johor River Watershed, Malaysia

摘要

This research introduced a super-high-resolution atmospheric model, AGCM20, to the Johor River Watershed in Malaysia to analyze future changes in rainfall characteristics, that is, annual, monthly, daily, and extreme rainfalls. The comparative analyses of the rainfall characteristics between the control (1979-2003) and future (2075-2099) periods clarified that more severe rainfall events would occur in the Northeast monsoon season. Moreover, there is a possibility that the onset of the Northeast monsoon season would become earlier and the intensity of rainfall events becomes quite higher among the decreased number of wet days. With regards to anticipated changes in extreme rainfall, the frequency of severe rainfall events would increase： it was estimated that the return period for the current 100-year event corresponds to 2.4 years in the future. The findings obtained from the AGCM20 outputs will be beneficial to construct the proper watershed management systems that consider the impacts of climate change.