비점오염 대리 모니터링 및 부하량 산정 기법 평가 = Evaluation of surrogate monitoring and load estimation method for non point source pollution

다국어 초록 (Multilingual Abstract)

Monitoring of nonpoint source pollution requires intensive labor and lab analysis cost. The aim of this study was to develop a surrogate method of monitoring SS and T-P and load estimation by using turbidity and runoff. Three different landuse subwatersheds representing rural(WJ), urban(JS), and mixed landuse(PYJ) were monitored during 2017/04/11∼2017/07/08. The predictor variables such as turbidity and runoff were continuously measured by turbidity sensor and water level sensor, while target variables such as SS and T-P were monitored by grab sampling method. Total number of samples were 60, 51 and 59 for WJ, JS and PYJ, respectively. Multiple regression equations were developed for predicting concentrations and loads of target variables. As a result, pearson’s correlation coefficient between turbidity and SS concentrations were 0.90, 0.92 and 0.94 for WJ, JS and PYJ, respectively. Concentrations of T-P also showed good results by surrogate monitoring, it showed 0.78 and 0.93 of pearson’s correlation coefficient with turbidity in WJ and JS, but PYJ showed unacceptable result. To evaluate performance of surrogate load estimation method, we predicted and compared to continuous loads on 2018/04/05 runoff event in WJ, which is not used for develop regression equations. Pearson’s correlation coefficient was 0.91 and 0.85, and Nash-Sutcliffe coefficient was showed 0.52 and 0.80 for SS and T-P. According to our result, surrogate monitoring method for SS and T-P was acceptable for rural watershed(WJ).