This study was conducted to suggest the concentration distribution of organic matters in 348 tributaries of Nakdong River, and
to review the validity of the conversion of organic matter indexes. The average concentration of organic matters in the
tributaries was TOC 2.4 mgC/L, DOC 2.1 mgC/L, COD 1.0 mgC/L, respectively. DOC ratio to TOC is 87% and COD ratio is
44%. First tributaries shows higher organic pollution than second tributaries. The correlation between TOC and COD was
relatively high as 0.796 (p < 0.01, n = 670). Based upon these results, a regression analysis was conducted. The results showed
that TOC concentration was 2.5 times higher than COD concentration. In conclusion, it is appropriate to use TOC for the
management of all organic matters. Furthermore, there is a need to build organic matter-related Databases for more rivers so as
to establish TOC standards and manage the water quality.
