Author(s): Dong Yeol Lee; Kyong Oh Baek

Linked Author(s): Kyong Oh Baek

Keywords: Lgae mitigation; EFDC; Dam operation; Pollution load management; Chlorophyll

Abstract: The purpose of this study is to analyze the quantitative effects of dam operation and pollution load management on algae reduction in rivers. The research subject was selected as a water area with large dams in the upper and lower streams. The study area was selected as the Bukhan River from Uiam Dam to Chuncheon Dam located in Gangwon Province, South Korea, and the Soyang River, which is a tributary of the Bukhan River and includes Soyang Dam. The selected research area was established as an EFDC (Environmental Fluid Dynamics Code) that can comprehensively simulate various variables related to the water environment, such as quantity and quality. As the first measure, the discharge volume and storage level of Uiam Dam, Chuncheon Dam, and Soyanggang Dam were adjusted to operate the dams within the water area. Nine dam operation scenarios were simulated and analyzed to determine the impact of each dam on Uiam Lake. The results showed that the concentration of chlorophyll-a was reduced by up to 38.8% at Uiam Dam 1, up to 61.0% at Uiam Dam 2, and up to 60.6% at Uiam Dam 3, depending on the dam's operation. Regarding the second measure, two scenarios were set up to analyze the change in water quality of Soyang Lake when the pollutant source was reduced in sub-watersheds. In the first scenario, T-P (total phosphorus) loads were reduced by 50% in 12 sub-watersheds, while in the second scenario, T-P load was reduced by 50% only in the six sub-watersheds closest to the Soyanggang Dam. Simulation results showed that chlorophyll-a concentration decreased by 20.2% in 12 subwatersheds when pollutants were reduced.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0441-cd

Year: 2023