The Impacts of Water Cycle Components on Streamflow in a Changing Climate of Korea: Historical and Future Trends

Abstract

This paper investigates the historical and future trends in water balance components and their impacts on streamflow. The trend analyses were applied to the daily climatic and hydrologic variables from 109 subbasins in Korea during the historical period and future period obtained by a multimodel ensemble of 13 global circulation models (GCMs) of the Coupled Model Intercomparison Project, Phase 5 (CMIP5). A calibrated hydrologic model, the precipitation-streamflow modeling system (PRMS) model, was applied to obtain hydrologic data. The results revealed apparent trends in streamflow, with increases in spring and decreases in the other seasons during the historical period. The reduction (or increase) in the amount of streamflow was counterbalanced by the reduction (or increase) in precipitation, groundwater, and soil moisture, which was mainly impacted by the increase (or reduction) in actual evapotranspiration. However, opposite trends are projected for the future period for streamflow and water cycle components, in which spring and winter are projected to have increasing trends mostly counterbalanced by the decreasing trends in precipitation and groundwater. The reasons for the reduction in streamflow include elevated evapotranspiration compared to precipitation, reduced soil moisture, and a significant decrease in groundwater recharge. In addition, the results of the seasonal variability among basins revealed higher variability in summer for the historical period and in winter for the future period, with maximum variability in the Sumjin River basin, indicating that streamflow fluctuated more strongly in the Sumjin River basin during the historical and future periods.

Ambient Air Quality Synergies with a 2050 Carbon Neutrality Pathway in South Korea

“…Therefore, the effects of low air quality in South Korea will worsen over time due to the steep increase in the aged population. Climate change is also predicted to have other, increasingly negative effects in South Korea [19][20][21][22]. For example, water quality in South Korea would be negatively affected by climate change [23].…”

“…The work aims to provide evidence for the potential of a 2050 carbon neutrality emissions pathway to synergistically improve atmospheric air quality, and thus support the case for more ambitious climate action in South Korea. The article first outlines the methodology used to calculate the greenhouse gases (GHGs) that would be avoided, as well as those of other air pollutants, as well as its methodology for calculating some of the health benefits of the climate Climate change is also predicted to have other, increasingly negative effects in South Korea [19][20][21][22]. For example, water quality in South Korea would be negatively affected by climate change [23].…”