| Title |
Accuracy Evaluation and Alert Level Setting for Real-time Cyanobacteria Measurement Using Receiver Operating Characteristic Curve Analysis |
| Authors |
송상환 ( Sanghwan Song ) ; 박종환 ( Jonghwan Park ) ; 강태우 ( Tae-woo Kang ) ; 김영석 ( Young-suk Kim ) ; 김지현 ( Jihyun Kim ) ; 강태구 ( Taegu Kang ) |
| DOI |
https://doi.org/10.15681/KSWE.2017.33.2.130 |
| Keywords |
Alert level; Cyanobacteria; Real-time measurement; Receiver operating characteristic |
| Abstract |
In order to evaluate the accuracy of real-time measurement of cyanobacterial fluorescence needed to predict cyanobacterial blooms, this research examined 357 pairs of data (from 2013-2016) consisting of both microscopic toxic cyanobacterial cell counts and concurrent real-time cyanobacterial concentrations, from two sites (YS1 and YS2) in the Yeongsan river. The high level of real-time cyanobacterial concentration was associated with exceeding 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; hence the measurement provides a highly accurate detection of cyanobacterial blooms. On the ROC curve, the early alert levels of real-time cyanobacteria ranging from 16 to -23 μg chl-a/L would produce an acceptable sensitivity of 79% and specificities greater than 90%. The real-time fluorescence measurement was an accurate indicator of cyanobacteria and can serve as a tool for detecting toxic cyanobacterial bloom events in the Yeongsan river. |