Water Quality Modelling for Nitrate Nitrogen Control Using HEC-RAS: Case Study of Nakdong River in South Korea

Water Quality Modelling for Nitrate Nitrogen Control Using HEC-RAS: Case Study of Nakdong River in South Korea

Kim, J. (TU Delft Water Resources; IHE Delft Institute for Water Education; K-water Convergence Institute)
Jonoski, Andreja (UNESCO-IHE; IHE Delft Institute for Water Education)
Solomatine, D.P. (TU Delft Water Resources; IHE Delft Institute for Water Education; Russian Academy of Sciences)
Goethals, Peter L. M. (Universiteit Gent)

2023

The World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA) provide guidelines on the maximum levels of nitrate nitrogen (NO3-N) contained in drinking water since excess nitrate ingestion may harm human health. Thus, monitoring and controlling the NO3-N concentration is of paramount importance, especially in sources of drinking water such as the Nakdong River in South Korea. This study addresses NO3-N pollution in the Nakdong River in South Korea, where such pollution mostly comes from diffuse sources in the catchment due to the agricultural use of fertilizers. The objective of this study is to suggest guidelines for designing strategies to control NO3-N in this river using a process-based model developed with HEC-RAS. The model was built based on water quality parameters (water temperature, dissolved oxygen, ammonia nitrogen, etc.) related to NO3-N dynamics incorporating hydraulic and meteorological data. This model simulated NO3-N dynamics downstream under 55 scenarios while focusing on a section near locations of drinking water intakes. The scenarios were constructed based on variations in water quantity and quality upstream. The simulation results showed that the peak concentration of NO3-N downstream could be directly controlled by limiting the NO3-N concentration upstream. Additionally, control of the flow rate upstream could also lead to a reduction in the overall average concentration of NO3-N downstream, but this predominantly occurred when the NO3-N concentration was decreasing. In conclusion, the design and implementation of strategies for the control of NO3-N downstream should be carried out after performing a quantitative analysis of the impact of different control measures for different downstream conditions using a water quality model.

water quality model
HEC-RAS
nitrate nitrogen (NO3-N)
Nakdong River
water quantity
guidelines

http://resolver.tudelft.nl/uuid:7a6fb4c6-d3ec-42ff-a0ca-a60a51a8e0db

https://doi.org/10.3390/w15020247

2073-4441

Water, 15 (2)

Institutional Repository

journal article

© 2023 J. Kim, Andreja Jonoski, D.P. Solomatine, Peter L. M. Goethals