Investigation on the contribution of non-point source pollution to water quality degradation of Jeonju River, South Korea

Most developed countries have effectively controlled point source pollution and have identified non-point source pollution as a major cause of water quality degradation. This study investigated the contribution of non-point source pollution to water quality degradation of Jeonju River, South Korea. A total of 10 automatic monitoring system was installed along Jeonju River, South Korea which was monitored from May 2015 to December 2017. From Seungam station to Geumhakbo station, the BOD concentration was found to be greater during rainy days compared to dry days. On the other hand, the BOD concentration was greater during dry days in tributaries, Singam station and Seumhakcheon station. For TOC, there was a varying trend where in higher concentration during dry days were observed for 50% of the monitoring stations while the concentrations remaining half were higher during rainy days. Except for the tributaries, SS concentration was found to be higher during rainy season compared to dry season. For nutrient concentration including TN and TP, higher concentration during rainy days were observed for 60% of the stations and 40% of the stations in Jeonju River, respectively. Overall, the results showed that during rainfall events, non-point pollutants flow into rivers and the concentration of most pollutants increases. The findings of this research may be used to develop non-point source pollution management strategies in Jeonju River.