Author(s): Dongil Seo; Jongtae Park; Youngmin Koo
Linked Author(s):
Keywords: Global Climate Change; RCP Scenarios; The Yongdam Lake; Water Quality Modeling; SWAT; CE-QUAL-W2
Abstract: Long term changes in pollutant loadings and water quality of the Yongdam Lake due to climate changes were estimated by using a basin model and a surface water quality model in series. Two Representative Concentration Pathways scenarios, RCP4.5 and RCP8.5 that stabilize radiative force at 4.5 (significant reduction) and 8.5 (current trend), respectively, were applied and their impacts were predicted. The SWAT model was selected in the basin to predict flow rates and loadings of major pollutants to the lake under climate change scenarios. Then, the CE-QUAL-W2 model was used to estimate water levels and water concentrations in the lake. Both models were applied for 6 years from 2010 to 2015 and the latter three years were used for calibrations and the first three year’s results were regarded as warming up periods. Using the models, future flow rate and water concentration were estimated for 80 years from 2016 to2095. The RCP8.5 scenario application results shows that future flow rate and water quality concentrations will be increased in flood seasons and decreased in dry seasons. This result indicates that drought and flood will become more serious and also their effects on water quality will be more serious in the future. The RCP4.5 scenario showed greater increase in flow rates and TSS and TP concentrations than RCP8.5scenarios despite the significant reduction in green house gas. This may be caused by increased air temperature followed by increased evapotranspiration that led surface runoff reduction in the basin area of the RCP8.5. This study suggests that dependent on characteristics of local climate change effect, impacts on the environmental may be different. Also, temporal distributions of precipitation pattern during simulation period and also in a year must be investigated thoroughly as simple arithmetic averages may not reflect detailed phenomena appropriately.
Year: 2018