| Title |
Assessment of Water Quality in the Lower Reaches Namhan River by using Statistical Analysis and Water Quality Index ( WQI) |
| Authors |
조용철 ( Yong-chul Cho ) ; 최현미 ( Hyeon-mi Choi ) ; 류인구 ( In-gu Ryu ) ; 김상훈 ( Sang-hun Kim ) ; 신동석 ( Dongseok Shin ) ; 유순주 ( Soonju Yu ) |
| DOI |
https://doi.org/10.15681/KSWE.2021.37.2.114 |
| Keywords |
Namhan River; RTWQI; Statistical analysis; WQI |
| Abstract |
Water pollution in the lower reaches of the Namhan River is getting worse due to drought and a decrease in water quantity due to climatic changes and hence is affecting the water quality of Paldang Lake. Accordingly, we have used a water quality index (WQI) and statistical analysis in this study to identify the characteristics of the water quality in the lower reaches of the Namhan River, the main causes of water pollution, and tributaries that need priority management. Typically, 10 items (WT, pH, EC, DO, BOD, COD, SS, T-N, T-P, and TOC) were used as the water quality factors for the statistical analysis, and the matrix of data was set as 324 × 10·1. The correlation analysis demonstrated a strong correlation between Chemical Oxygen Demand (COD) and T-P with a high statistical significance (r=0.700, p<0.01). Furthermore, the result of principal component analysis (PCA) revealed that the main factors affecting the change in water quality were T-P and organic substances introduced into the water by rainfall. Based on the Mann-Kendall test, a statistically significant increase in pH was observed in SH-1, DL, SH-2, CM, and BH, along with an increase in WQI in SH-2 and SM. BH was identified as a tributary that needs priority management in the lower r eaches o f t he N amhan R iver, with a “ Somewhat p oor” ( IV) g rade i n T -P, “Fair” g rade i n WQI, and “Marginal” grade in summer. |