강우시 흙탕물 발생 하천의 수질개선 효과분석

We monitored the monthly change of water quality on the site of the nonpoint management area of Heanmyeon in Yang-gu County from 2009 to 2015. We found that SS, TP, and COD values were highly correlated with turbidity water concentration. Additionally, we monitored changes in turbidity using a real-time monitoring system. Using the data, the stage-discharge rating curve was calculated and we analyzed the correlations of COD, SS, and TP with the turbidity value. We found that SS concentration decreased by 48.1~83.6% under 10~30 mm rain fall and 72.1~86.6% under 30~50 mm rainfall as a result of comparing the event mean concentrations (EMCs) of SS with rainfall events that occurred in 2010 and 2014. We analyzed the rainfall and SS discharge rate per area based on the log data. Water quality was higher in 2014 than in 2010 during rainfall events. We concluded that the water quality at Mandae watershed was improved continuously by progress of non-point management policy.