Development of customized water quality index for medium- and long-term evaluation of urban river water quality

Abstract In this study, a customized WQI (Seoul water quality index, S-WQI) for urban rivers that can ultimately reflect their characteristics was developed by modifying and supplementing the existing Bascarόn calculation method through linkage with statistical methods such as factor analysis. We used data generated monthly at 17 monitoring networks (WQMNs) in Seoul 18 years, from 2002 to 2019. Results of research show S-WQI showed an average 70 out 100, ‘good (II)’ grades, whereas grade according environmental standards ‘slightly good (II),’ R2 value 0.8298. The annual found be 39 (bad) 97 (very good), 72 (good). Through S-WQI, rivers, judged reasonable index represent river quality. This is because it easy apply uses relatively fewer items than calculated past, highly likely linked currently implemented system. addition, extend application various survey points, based on methodology performed derive indices modified (MS-WQI), adding new changing some items, also possible develop advanced considering watershed measurement items.