2025 Volume 81 Issue 16 Article ID: 24-16008
Many climate change-aware assessments have been made for the increase in flood discharge due to climate change. The purpose of this study is to understand the future frequency and trend of climate change in the Shingu River system by the difference between the 20 km resolution with a warming projection d4PDF and the 5 km resolution with dynamical downscaling. In this study, we focused on the following three points. (1) the average rainfall in the catchment area of inland rivers and the main river within the catchment area, (2) the total runoff of the entire catchment area, and (3) the simultaneous occurrence of the main river and its tributary inland rivers. As a result, the rainfall of 5 km resolution is generally close to the real rainfall. In addition, the rainfall and calculated discharge of 20 km resolution tend to be underestimated compared to the 5 km resolution when the above three future experimental values are considered. At the least, it suggests that 5km resolution is appropriate when using future projections in this basin, because this underestimates the simultaneous occurrence of the main river flow and heavy rainfall in the tributary basins.
