ROC 분석을 이용한 수질자동측정소 실시간 남조류 측정의 정확성 평가 및 경보기준 설정

• Published in: 한국물환경학회지 Vol. 33; no. 2; pp. 130 - 139
• Main Authors: 송상환, 박종환, 강태우, 김영석, 김지현, 강태구, Song, Sanghwan, Park, Jong-hwan, Kang, Tae-Woo, Kim, Young-Suk, Kim, Jihyun, Kang, Taegu
• Format: Journal Article
• Language: Korean
• Published: 한국물환경학회 31.03.2017
• Subjects: 환경공학; Alert level; Receiver operating characteristic; Real-time measurement; Cyanobacteria
• ISSN: 2289-0971; 2289-098X
• DOI: 10.15681/KSWE.2017.33.2.130

With the need to evaluate accuracy of real-time measurement of cyanobacterial fluorescence to determine cyanobacterial blooms, this research examined 357 paired data (2013-2016) comprising both microscopic toxic cyanobacterial cell counts and concurrent real-time cyanobacterial concentrations at 2 sites (YS1 and YS2) in Yeongsan river. The increase in real-time cyanobacterial concentration was closely associated with the exceedance of 5,000 cyanobacterial cells/ml (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.03-1.12) and 10,000 cells/ml (OR 1.08, 95% CI 1.04-1.12) at YS2 site. The area under the receiver operating characteristic (ROC) curve for the real-time cyanobacterial measurement at the YS2 site was 0.93, which indicates the measurement provides a high accurate detection of cyanobacterial blooms. On the ROC curve, the early alert levels of real-time cyanobacteria ranging $16-23{\mu}g$ chl-a/L would produce acceptable sensitivity of 79% and specificities greater than 90%. The real-time fluorescence measurement was found to be an accurate indicator of cyanobacteria and can serve as a tool for detecting toxic cyanobacterial bloom events in Youngsan river.