Korean Journal of Ecology and Environment (생태와환경)

The Korean Society of Limnology (한국수생태학회)
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Influence of the Asian Monsoon on Seasonal Fluctuations of Water Quality in a Mountainous Stream

산간 계류성 하천의 계절적 수질변동에 대한 몬순강우의 영향

  • Shin, In-Chul (Chungnam Health and Environmental Research Institute) ;
  • An, Kwang-Guk (School of Bioscience and Biotechnology, Chungnam National University)
  • Published : 2005.03.31
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Abstract

The present study was to determine how seasonal rainfall intensity influences nutrient dynamics, ionic contents, oxygen demands, and suspended solids in a lotic ecosystem. Largest seasonal variabilities in most parameters occurred during the two months of July to August and these were closely associated with large spate of rainfall. Dissolved oxygen (DO) had an inverse function of water temperature (r = = = - 0.986, p<0.001). Minimum pH values of<6.5 were observed in the late August when rainfall peaked in the study site, indicating an ionic dilution of stream water by precipitation. Electrical conductivity (EC) was greater during summer than any other seasons, so the overall conductivity values had direct correlation (r = 0.527, p<0.01) with precipitation. Ionic dilution, however, was evident 4 ${\sim}$ 5 days later in short or 1 ${\sim}$ 2 weeks in long after the intense rain, indicating a time-lag phenomenon of conductivity. Daily COD values varied from 0.8 mg $L^{-1}$ to 7.9 mg $L^{-1}$ and their seasonal pattern was similar (r = 0.548, p<0.001) to that of BOD. Total nitrogen (TN) varied little compared to total phosphorus (TP) and was minimum in the base flow of March. In contrast, major input of TP occurred during the period of summer monsoon and this pattern was similar to suspended solids, implying that TP is closely associated (r = 0.890, p<0.01) with suspended inorganic solids. Mass ratios of TN : TP were determined by TP (r= -0.509, p<0.01) rather than TN (r= -0.209, p<0.01). The N : P ratios indicated that phosphorus was a potential primary limiting nutrient for the stream productivity. Overall data suggest that rainfall intensity was considered as a primary key component regulating water chemistry in the stream and maximum variation in water quality was attributed to the largest runoff spate during the summer monsoon.

본 연구는 하절기 집중강우가 하천의 부영양화도, 이온변화, 산소요구량에 영향 평가로서 수질 변수들 간의 상호관계를 분석하였다. 용존산소(DO) 농도는 수온과 역상관 관계 (r= -0.99, p<0.001)를 보였다. 대부분 수질변이는 7 ${\sim}$ 8월에 발생 하였으며, 이들의 대부분은 하절기 집중강우와 직접적인 연관성을 보였다. pH의 경우 6.5 이하의 최소값은 최대 강우를 보인 8월에 관측되었는데, 이는 강우에 의한 수소이온농도의 희석현상에 의한 것으로 사료되었다. 전기전도도 또한 강우분포를 반영하였다. 즉, EC 값은 다른 계절보다 하절기에 좀 더 높은 값을 보였으며, 강우와의 직접적 연관성을 보였다. 연구결과에 따르면, 이온희석 현상은 강우 전의 하절기에는 높았지만, 집중강우 후 짧게는 4 ${\sim}$ 5일 길게는 1 ${\sim}$ 2주 후에 이온이 희석되는 것으로 나타나 강우와 하천수의 이온농도사이에 뚜렷한 반응시간의 지체현상을 보였다. COD의 계절적 변화 페턴은 BOD와 유사한(r= 0.55, p<0.001) 양상을 보였다. 총질소 (TN)는 총인 (TP)에 비해 변이 폭이 적었으며, 3월의 갈수기에 최소값을 보였다. 대조적으로, 총인 유입은 하절기 몬순동안에 주로 발생하였고, 총부유물(TSS)과 유사한 계절 변화 양상을 보여인(P)의 증가가 수계에서 유발되는 무기성부유물과 밀접하게 연관성을 갖는 것으로 나타났다. 총인: 총질소의 무게비는 질소 변이 (r= -0.21, p<0.01)보다는 총인(r= -0.51, p<0.01)의 변이에 의해 결정되었으며, 총인이 제한 요인으로 작용할 것으로 사료되었다. 본 계류형 하천에서 수질을 조절하는 1차 요인은 강우시기 및 강고로 사료 되었으며, 최대 변이는 하절기의 첨두강우와 일치하였다.

Keywords

References

  1. 강태호. 1998. 도시하천에서의 강우와 유출 및 수질 예측기법 개발에 관한 연구, 경기대학교 토목대학원 박사학위논문, p. 2-16
  2. 금강환경관리청. 1999. 금강 중역권 수질오염원 현황. 62 pp
  3. 김범철, 김윤희. 2004. 아시아 몬순지역의 대형댐(소양호)에서 의 인순환과 2차원모델의 적용. 한국육수학회지 37(2): 205-212
  4. 신재기, 황순진, 조경제. 2003. 평택호와 주요 하천의 수환경 및 오염도평가. 한국육수학회지 36(1): 38-47
  5. 안광국, 정승현, 최신석. 2001. 생물보전지수(Index of Biological Integrity) 및 서식지평가지수 (Qualitative Habitat Evaluation Index)를 이용한 평창강의 수환경 평가. 한국육수학회지 34: 153-165
  6. Allan, J.D. 1995. Stream ecology: structure and function of running waters. Chapman and Hall Pub. 1st Eds, pp. 388
  7. An, K-G. 2000a. Dynamic changes of dissolved oxygen during summer monsoon. Korean J. Limnol. 33: 213- 221
  8. An, K-G. 2000b. An influence of point-source and flow events on inorganic nitrogen fraction in a large artificial reservoir. Korean J. Limnol. 33: 350-357
  9. 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 (1-4): 27-49 https://doi.org/10.1023/A:1025602213674
  10. 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
  11. An, K-G. and S.S. Park. 2002. Indirect influence of the summer monsoon on chlorophyll-total phosphorus models in reservoirs: A case study. Ecological Modelling 152(2-3): 191-203 https://doi.org/10.1016/S0304-3800(02)00020-0
  12. An, K-G., J-Y. Shin and S-S Park. 2002. An evaluation of a river health using the Index of Biological Integrity along with relations to chemical and habitat conditions. Environment International 28(5): 411-420 https://doi.org/10.1016/S0160-4120(02)00066-1
  13. APHA. 1985. Standard methods for the examination of water and wastewater. 16th ed. New York, American Public Health Association. 874pp
  14. Cameron, E.M. 1996. Hydrogeochemistry of Fraser River, British Columbia: seasonal variation in major and minor components. J. of Hydrology 182: 209-225 https://doi.org/10.1016/0022-1694(95)02924-9
  15. Collins, R. and A. Jenkins. 1996. The impact of agricultural land use on stream chemistry in the Middle Hills of the Himalayas. J. of Hydrology 185: 71-86 https://doi.org/10.1016/0022-1694(95)03008-5
  16. Dillon, P.J. and F.H. Rigler. 1974. The phosphorus-chlorophyll relationship in lakes. Limnol. Oceanogr. 19: 767- 781 https://doi.org/10.4319/lo.1974.19.5.0767
  17. Dodds, W.K, J.R. Jones and E.B. Welch. 1998. Suggested classification of stream trophic state: Distributions of temperate stream types by chlorophyll, total nitrogen, and phosphorus. Wat. Res. 32(5): 1455-1462 https://doi.org/10.1016/S0043-1354(97)00370-9
  18. Grim, N.B. and S.G. Fisher. 1986. Nitrogen limitation in a Sonoran desert stream. J. N. Am. Benthol. Soc. 5: 2-15 https://doi.org/10.2307/1467743
  19. Meyer, J.L., W.H. McDowell, T.L. Bott, J.W. Elwwood, C. Ishizaki, J.M. Melack and P.A. Rublee. 1988. Elemental dynamics in streams. J. N. Benthol. Soc. 7: 410- 432 https://doi.org/10.2307/1467299
  20. Ostry, R.C. 1982. Relationship of water quality and pollutant to land uses in adjoining watershed. Water Res. Bull. 18: 99-104 https://doi.org/10.1111/j.1752-1688.1982.tb04534.x
  21. Perkins, B. and J.R. Jones. 1994. Temporal variability in a midwestern stream during spring. Verh. Internat. Verein. Limnol. 25: 1471-1476