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

Linked Author(s): Kyong Oh Baek

Keywords: Harmful algae; Yeongju Dam; Residence time; Water quality modeling; Chlorophyll

Abstract: Due to climate change, green algae blooms have become frequent not only domestically but also globally, and the risk of toxicity of harmful algal blooms (HABs) has recently emerged. It is known that blue-green algae, a representative harmful algae, is generated by the intersection of three factors: water temperature, residence time, and nutrients. In this study, water quality simulation was performed using EFDC, a quasi-three-dimensional numerical model, to analyze changes in water quality according to the decrease in residence time due to the full opening of Yeongju Dam in Naeseong Stream of Korea. In fact, the concentration of chlorophyll- a in the Yeongju Dam in the summer of 2021 was significant, exceeding the 'algae warning' for a long time based on the past algae warning system. On the other hand, as a result of the simulation under the condition that the dam gates were fully opened, the concentration of chlorophyll-a during the simulation period was mostly reduced below the 'algae warning' level. It was confirmed that reducing the residence time by generating the flow of Naeseong Stream is a method to immediately reduce algae blooms in Yeongju Dam.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0319-cd

Year: 2023