미래 기후변화 시나리오에 따른 한반도 유역별 극한 강수 변화 전망

Abstract

For the assessment of the future flood risk of 26 watersheds in South Korea, we analyze the change in extreme precipitation with a 100-year return period under global warming. We use downscaled high-resolution observation and bias-corrected future climate change scenario data from the National Institute of Meteorological Sciences for this purpose. In the high-CO₂ emission scenario (SSP5-8.5), the average rates of change in 100-year return period precipitation at 26 watersheds is projected to increase about 29%, 46%, and 53% in the early (2021 ~ 2040), mid (2041 ~ 2060), and late (2081 ~ 2100) 21st century, respectively, relative to the present climate. The number of watersheds with a 100-year return period precipitation increase of 50% or more compared to the present climate is predicted to increase significantly in the late 21st century. On the other hand, in the low-CO₂ emission scenario (SSP1-2.6), after the mid-21st century, the increase in 100-year return period precipitation is much less than that of the high-CO₂ emission scenario since the rate of change is projected to increase about 31%, 31%, and 29% in the early, mid, and late periods, respectively. Furthermore, most watersheds show a 100-year return period precipitation increase of 50% or less. These results imply that the possibility of flooding by extreme precipitation can be reduced through achievement of a carbon-neutral policy.