Impact of Climate Change on Discharge in Small Mountainous Mizoguthi Catchment, Japan

抄録

  This paper presents a comprehensive analysis of climate change impacts on the discharge in the small mountainous Mizoguthi Catchment, Japan, using a large ensemble of climate simulations from the Database for Policy Decision Making for Future Climate Change (d4PDF) through the TOPMODEL hydrological model. Two sets of experiments for a 60-year period were conducted using d4PDF data: historical and 4-K-warmer climate simulation experiments. The precipitation and discharge analyses were based on cumulative frequency, box–whisker plots, flow duration curves, and return periods under historical and 4-K-warmer climate conditions. Results showed that irrigation periods with low precipitation occurred more frequently, and the catchment was more likely to become more seriously dry than it is at present. Finally, the return period results showed that droughts are likely to have major impacts due to the expected decrease in discharge. These results suggest severe challenges to water resources in the catchment under 4-K-warmer climate conditions and should be used to mitigate the adverse effects of drought in the study area by adopting appropriate adaption strategies.