Longitudinal Gradients and Seasonal Dynamics of Nutrients, Organic Matter and Conductivity Along the Main Axis of Han-River

  • Kim, Bit-Na (School of Bioscience and Biotechnology, Chungnam National University) ;
  • Lee, Sang-Jae (School of Bioscience and Biotechnology, Chungnam National University) ;
  • Seo, Jin-Won (Korea Institute of Water and Environment, Korea Water Resources Corporation) ;
  • An, Kwang-Guk (School of Bioscience and Biotechnology, Chungnam National University)
  • Published : 2008.12.31

Abstract

The purpose of the study was to evaluate spatial and temporal dynamics of nutrients (TN, TP), organic pollution (BOD, COD), and ionic dynamics (electrical conductivity, EC) in the North Han-River, South Han-River, and merged downriver using the dataset of $1998{\sim}2007$, obtained from the MEK (Ministry of Environment, Korea). Accord. ing to interannual nutrient analysis, TN varied slightly in the North Han-River and South Han-River, but decreased in the merged downriver along with BOD. Longitudinal analysis in the water quality showed that BOD, COD, and nutrients had linear decreasing trend along the main axis of headwater-to-downriver. Concentrations of TP and TN in the North Han-River averaged $26.97{\mu}g\;L^{-1}$, $1.696mg\;L^{-1}$, respectively, which were minimum in the three watersheds, followed by South Han-River and then the merged downriver in order. Ratios of TN:TP in the watersheds were >40 in all the sites, indicating that nitrogen may be enough for periphyton or phytoplankton growth and phosphorus may be limited partially. After the North Han-River water is merged with South Han-River, the concentrations of BOD, COD, TN, and TP were similar to the values of $S6{\sim}S7$, respectively or a little bit higher, but increased abruptly in Site M4 (Fig. 3). Thus, mean values of all the water quality parameters in the reach of $M4{\sim}M7$ sites were greater than any other sites. Seasonal data analysis indicated that BOD and EC in the downstream ($S3{\sim}S7$) was greater in the premonsoon than two seasons of the monsoon and postmonsoon, and no significant differences in BOD between the three seasons were found in the upstream ($S1{\sim}S2$). Empirical models of COD in the merged downriver was predicted ($R^2=0.87$, p>0.01, slope = 0.84, intercept = -1.28) well by EC. These results suggest that EC to be measured easily in the field may be used for estimations of nutrients and organic matter pollutions in the merged downriver and these linear models are cost-effective for the monitoring of the parameters.

Keywords

References

  1. An, K.G. 2000a. An influence of point-source and flow events on inorganic nitrogen fractions in a large artificial reservoir. Korean Journal of Limnology 33: 350-357
  2. An, K.G. 2000b. Monsoon inflow as a major source of in-lake phosphorous. Korean Journal of Limnology 33: 222-229
  3. An, K.G. 2001. Hydrological significance on interannual variability of cations, anions, and conductivity in a large reservoir ecosystem. Korean Jounal of Limnology 34: 1-8
  4. An, K.G. and D.S. Kim. 2003. Response of lake water quality to nutrient inputs from various streams and in-lake fishfarms. Water, Air, and Soil Pollution 149: 27-49 https://doi.org/10.1023/A:1025602213674
  5. An, K.G. and I.C. Shin. 2005. Influence of the asian monsoon on seasonal fluctuations of water quality in a mountainous stream. Korean Journal of Limnology 38: 54-62
  6. An, K.G. and J.R. Jones. 2000. Temporal and spatial patterns in ionic salinity and suspended solids in a reservoir influenced by the Asian monsoon. Hydrobiologia 436: 179-189 https://doi.org/10.1023/A:1026578117878
  7. Baker, A., D. Ward, S.H. Lieten, R. Periera, E.C. Simpson and M. Slater. 2004. Measurement of proteinlike fluorescence in river and wastewater using a handheld spectrophotometer. Water Research 38: 2934-2938 https://doi.org/10.1016/j.watres.2004.04.023
  8. Cooke, G.W. and R.J.B. Williams. 1973. Significance of man-made sources of phosphorus: fertilizers and farming. Water Research 7: 19-33 https://doi.org/10.1016/0043-1354(73)90150-4
  9. Faulkner, H., V. Edmonds-Brown and A. Green. 2000. Problems of quality designation in diffusely polluted urban streams-the case of Pymme's Brook, north London. Environmental Pollution 109: 91-107 https://doi.org/10.1016/S0269-7491(99)00227-4
  10. Happer, D. 1992. Eutrophication of fresh water: principles, problems and restoration. p. 376-377 In: Reviews in Fish Biology and Fisheries (Happer eds.). Chapman & Hall London
  11. Huh, I.R., G.H. Yi, J.Y. Choi., U.H. Jeong and Y.S. Lee. 1999. Research about water conservation on upstream of the Han river. Jounal of Korean Society on Water Quality 15: 305-314
  12. Jeong, S.W., J.H. Lee and H.G. Heo. 2004. Environmental studies in the lower part of the Han river 6. the statistical analysis of eutrophication factors. Korean Journal of Limnology 37: 78-86
  13. Kim, B.C. and Y.H. Kim. 2004. Phosphorus cycle in a deep reservoir in asian monsoon area (lake Soyang, Korea) and the modeling with a 2-D hydrodynamic water quality model. Korean Jounal of Limnology 37: 205-212
  14. Kim, D.S., B.C. Kim, G.S. Hwang and J.H. Park. 1995. Trend of eutrophication in lake Paldang (1988- 1994). Jounal of Korean Society on Water Quality 11: 295-302
  15. Kim, J.K., M.S. Shin., C.W. Jang., S.M. Jung and B.C. Kim. 2007. Comparison of TOC and DOC distribution and the oxidation efficiency of BOD and COD in several reservoirs and rivers in the Han river system. Journal of Korean Society on Water Quality 23: 72-80
  16. Kim, J.M., H.R. Noh., S.N. Heo., H.J. Yang and J.D. Park. 2005. A study on the water quality affected by the rainfall and influent rivers in paldang reservoir. Korea. Jounal of Korean Society on Water Quality 21: 277-283
  17. Lee, T.G. and B.H. Sik 2001. The management for the water quality of Jung-rang river. Journal of Korea Technological Society of Water and Waste Water Treatment 9: 45-52
  18. Mancini, L., P. Formichetti, A.M. D'Angelo, E. Pierdominici, A. Sorace, P. Bottoni, M. laconelli, C. Ferrari, L. Tancioni, N. Rossi and A. Rossi. 2004. Freshwater quality in urban areas: a case study from Rome, Italy. Microchemical Journal 79: 177-183
  19. Ministry of Construction & Transportation. 2004. Researches of the Han river watershed
  20. Park, S.S., S.H. Lee, B.K. Park and S.H. Lee. 1995. Nonparametric statistical comparison of tributary water qualities between the south and north branches of the Han river, Korean Journal of Limnology 28: 299-307
  21. Seoul city. 2007. Researches of the Han river ecosystem
  22. Shin, J.K., J.L. Cho., S.J. Hwang and K.J. Cho. 2000. Eutrophication and water pollution characteristics of the Kyongan stream to paltang reservoir. Korean Jounal of Limnology 33: 387-394
  23. Suh, M.Y., B.H. Kim and K.S. Bae. 2007. Fluctuation of environemental factors and dynamics of phytoplankton communities in lower part of the Han river. Korean Journal of Limnology 40: 395-402
  24. Yoo, H.S. 2002. Statistical analysis of factors affecting the Han river water quality. Journal of Korean Society of Environmental Engineers 24: 2139-2150