대청호의 시공간적 수질 변화 특성 및 호수내 유입지천의 영향

Spatio-temporal Fluctuations with Influences of Inflowing Tributary Streams on Water Quality in Daecheong Reservoir

  • 김경현 (충남대학교 생명시스템과학대학 생물과학과) ;
  • 이재훈 (충남대학교 생명시스템과학대학 생물과학과) ;
  • 안광국 (충남대학교 생명시스템과학대학 생물과학과)
  • Kim, Gyung-Hyun (Department of Biological Sciences, College of Biosciences and Biotechnology, Chungnam National University) ;
  • Lee, Jae-Hoon (Department of Biological Sciences, College of Biosciences and Biotechnology, Chungnam National University) ;
  • An, Kwang-Guk (Department of Biological Sciences, College of Biosciences and Biotechnology, Chungnam National University)
  • 투고 : 2012.01.05
  • 심사 : 2012.05.31
  • 발행 : 2012.06.30

초록

본 연구는 대청호 본류유역 7개 지점과 대청호 유입지류 8개 지점을 선정하여 2001년부터 2010년까지 측정된 환경부 수질자료를 분석해 시 공간적 변이를 파악하고, 더불어 대청호 유입 지류에 의한 대청호 수질의 영향을 분석하였다. 본류 수역의 연평균 수질 자료 분석결과에 따르면, 질소(N) 및 인(P)의 농도는 호수대 내에서 상류역에서 댐(M7)으로 갈수록 거리에 따라 1차 함수적으로 감소하는 경향을 보였다. 호수내 유수대(M1~M3), 전이대(M4~M6) 및 정수대(M7)의 TN과 TP는 외국 인공호들과 마찬가지로 뚜렷한 Zonation 패턴을 보였다. 반면, 호수내 유기물 지표로서 엽록소(CHL)와 BOD는 TN과 TP의 구간별 연속적 감소 패턴과는 달리 전이대에서 최고치를 보였다. 유수대에서는 몬순 집중강우기인 8월에 TP가 377 ${\mu}gL^{-1}$로서 최대치를 보였으나, 정수대에서는 7월에 165 ${\mu}gL^{-1}$로서 최대치를 보였다. 한편, 유수대의 TN은 3월 최대치(8.52 $mg\;L^{-1}$)를 보였으며, 정수대의 TN은 본류에 비해 상대적으로 낮은 수치를 보였고, 최대치는 8월 (3.76 $mg\;L^{-1}$)에 관측되었다. 집중강우에 의한 이온희석현상은 9~10월에 극명하게 나타났다. 호수내 제한요인의 평가지표로서 이용되는 TN : TP 비는 88 이상으로서 이미 대청호는 질소가 과잉공급 상태인 것으로 사료되었다. 몬순강우에 따라 호수의 수질은 악화되는 경향을 보였으며, TP와 SS가 강우에 가장 민감하게 반응하였고, CHL은 정수대의 변이 폭이 높게 나타났다. 호수내로 유입되는 지천의 영향평가에 따르면, 도심형 하천이자 농공단지와 하수처리장의 영향을 받고 있는 T1, T2 및 호수내에 가장 큰 영향을 줄 것으로 사료되는 옥천천(T5)의 오염도가 가장 높게 나타났다. 호수의 경험적 모델 분석에 다르면, 호수내에서 CHL의 변이는 유수대($R_z$: $R_2$=0.044, p=0.264)와 전이대 ($T_z$: $R_2$=0.126, p=0.054)에서 TN에 의해 통계학적 유의성을 보이지 않았으나, 정수대($L_z$)에서 질소는 조류 생장에 억제효과($R_2$=0.458, p=0.032)를 가질 수 있는 것으로 나타났다. 한편, 유입 지천($I_w$)의 TN은 호수내($I_r$)의 CHL의 변이에 통계학적으로 유의성이 없는 것으로 나타났고($R_2$=0.258, p=0.110), 유입 지천($I_w$)의 TP는 호수내($I_r$)의 CHL의 변이에 통계학적으로 유의성이 있는 것으로 나타났다 ($R_2$=0.567, p=0.005). 즉, 지천의 TP 유입은 대청호의 조류 생장에 직접적으로 영향을 주는 것을 의미하였다. 한편, 대청호의 TN : TP 비는 지천의 TN보다는 TP에 의한 영향을 받는 것으로 나타나 결국 TN : TP 비는 직접적으로 인(P)의 농도에 의해 조절되는 것으로 나타났다. 따라서 호수내의 여름철 TP와 SS 유입을 최소화 시키고, 높은 인이 유입되는 도심형 하천(옥천천)의 수질 개선이 대청호의 수질 개선에 큰 도움을 줄 것으로 사료되었다.

The objectives of this study were to analyze the longitudinal gradient and temporal variations of water quality in Daecheong Reservoir in relation to the major inflowing streams from the watershed, during 2001~2010. For the study, we selected 7 main-stream sites of the reservoir along the main axis of the reservoir, from the headwater to the dam and 8 tributary streams. In-reservoir nutrients of TN and TP showed longitudinal declines from the headwater to the dam, which results in a distinct zonation of the riverine ($R_z$, M1~M3), transition ($T_z$, M4~M6), and lacustrine zone ($L_z$, M7) in water quality, as shown in other foreign reservoirs. Chlorophyll-a (CHL) and BOD as an indicator of organic matter, were maximum in the $T_z$. Concentration of total phosphorus (TP) was the highest (8.52 $mg\;L^{-1}$) on March in the $R_z$, and was the highest (165 ${\mu}g\;L^{-1}$) in the $L_z$ on July. Values of TN was the maximum (377 ${\mu}g\;L^{-1}$) on August in the $R_z$, and was the highest (3.76 $mg\;L^{-1}$) in the $L_z$ on August. Ionic dilution was evident during September~October, after the monsoon rain. The mean ratios of TN : TP, as an indicator of limiting factor, were 88, which indicates that nitrogen is a surplus for phytoplankton growth in this system. Nutrient analysis of inflowing streams showed that major nutrient sources were headwater streams of T1~T2 and Ockcheon-Stream of T5, and the most influential inflowing stream to the reservoir was T5, which is located in the mid-reservoir, and is directly influenced by the waste-water treatment plants. The key parameters, influenced by the monsoon rain, were TP and suspended solids (SS). Empirical models of trophic variables indicated that variations of CHL in the $R_z$ ($R^2$=0.044, p=0.264) and $T_z$ ($R^2$=0.126, p=0.054) were not accounted by TN, but were significant (p=0.032) in the $L_z$. The variation of the log-transformed $I_r$-CHL was not accounted ($R^2$=0.258, p=0.110) by $I_w$-TN of inflowing streams, but was determined ($R^2$=0.567, p=0.005) by $I_w$-TP of inflowing streams. In other words, TP inputs from the inflowing streams were the major determinants on the in-reservoir phytoplankton growth. Regression analysis of TN : TP suggested that the ratio was determined by P, rather than N. Overall, our data suggest that TP and suspended solids, during the summer flood period, should be reduced from the eutrophication control and P-input from Ockcheon-Stream should be controlled for water quality improvement.

키워드

참고문헌

  1. 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(1): 54- 62.
  2. An, K.G. and J.W. Choi. 2006. Integrated ecological health assessments in Cho River. Korean Journal of Limnology 39(3): 320-330.
  3. An, K.G. and W.M. Yang. 2007. Water quality characteristics in Keum River watershed. Korean Journal of Limnology 40(1): 110-120.
  4. An, K.G., J.K. Kim and S.J. Lee. 2008. Reservoir trophic state and empirical model analysis, based on nutrients, transparency, and chlorophyll-a along with their relations among the parameters. Korean Journal of Environmental Biology 26(3): 252-263.
  5. Bae, D.Y., E.C. Yang, S.H. Jung, J.H. Lee and K.G. An. 2007. Nutrients and chlorophyll dynamics along the longitudinal gradients of Daechung Reservoir. Korean Journal of Limnology 40(2): 285-293.
  6. Borchardt, M.A. 1996. Nutrients. p. 184-227. In: Algal Ecology (Stevenson, R.J., M.L. Bothwell and R.L. Low, eds.). Academic Press, NewYork.
  7. Carlson, R.E. and J. Simpson. 1996. A Coordinator's guide to volunteer lake monitoring methods. North American Lake Management Society pp. 96.
  8. Cheon, S.U., J.A. Lee, J.J. Lee, Y.B. Yoo, K.C. Bang and Y.J. Lee. 2006. Relationship among inflow volume, water quality and algal growth in the Daecheong Lake. Korean Journal on Water Quality 22: 342-349.
  9. Chung, S.W. and J.H. Park. 2005. Application of Korea water quality index for the assessment of river water quality in the basin of Daecheong Lake. Korean Journal of Limnology 21(5): 470-476.
  10. 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. Water Research 32(5): 1455-1462. https://doi.org/10.1016/S0043-1354(97)00370-9
  11. Downing, J.A. and E. McCauley. 1992. The nitrogen: phosphorus relationship in lakes. Limnology and Oceanography 37(5): 936-945. https://doi.org/10.4319/lo.1992.37.5.0936
  12. Forsberg, G. and S.O. Ryding. 1980. Eutrophication parameters and tropic state indices in 30 waste receiving Swedish lakes. Archieves of Hydrobiologia 89: 189-207.
  13. Han, J.H. and K.G. An. 2008. Water quality variation dynamics between artificial reservoir and effected downstream watershed: The case study. Korean Journal of Limnology 41(3): 382-394.
  14. Han, J.H., J.Y. Lee and K.G. An. 2010. Interannual and seasonal variations of water quality in terms of size dimension on multi-purpose Korean Dam Reservoirs along with the characteristics of longitudinal gradients. Korean Journal of Limnology 43(2): 319-337.
  15. Harper, D. 1992. Eutrophication of freshwater; principles, problems and restoration, Chapman and Hall, London. p. 329.
  16. Hecky, R.E. and P. Kilham. 1988. Nutrient limitation of phytoplankton in freshwater and marine environments: A review of recent evidence on the effects of enrichments. Limnology and Oceanography 33: 796-822. https://doi.org/10.4319/lo.1988.33.4_part_2.0796
  17. Heo, W.M., B.C. Kim, Y. Kim and K.S. Choi. 1998. Storm runoff of phosphorus from nonpoint sources into Lake Soyang and transportation of turbid watermass within the lake. Korean Journal of Limnology 31(1): 1-8.
  18. Joung, S.H., C.Y. Ahn, A.R. Choi, K.Y. Jang and H.M. Oh. 2005. Relation between rainfall and phytoplankton community in Daechung Reservoir. Korean Journal of Environmental Biology 23: 57-63.
  19. Kang, S.A. and K.G. An. 2006. Spatio-temporal variation analysis of physico-chemical water quality in the Yeongsan- River watershed. Korean Journal of Limnology 39(1): 73-84.
  20. 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 [CE-QUAL-W2]. Korean Journal of Limnology 37(2): 205-212.
  21. Kim, J.M., S.N. Heo, H.R. Noh, H.J. Yang and M.S. Han. 2003. Relationship between limnological characteristics and algal bloom in lake-type and river-type reservoirs, Korea. Korean Journal of Limnology 36(2): 124-138.
  22. Kim, J.Y. 1996. A study on variation characteristics and correlationships of water quality in Daecheong Lake basin. Journal of the Korean Environmental Sciences Society 5(6): 763-770.
  23. Kim, J.Y. 1998. A study on the evaluation and prediction of the eutrophication for the lakes in Korea. Journal of the Korean Environmental Sciences Society 7(4): 441-449.
  24. Kim, O.J. and O.M. Lee. 2011. Phytoplankton community and the evaluation of water quality status in So-ok Stream, the inflowing stream to Daechung Lake. Korean Journal of Limnology 44(2): 113-128.
  25. Kim, Y.P. and K.G. An. 2010. Characteristics of water quality in Hyeongsan River watershed. Korean Journal of Limnology 43(1): 150-160.
  26. Kimmel, B.L. and A.W. Groeger. 1984. Factors controlling phytoplankton production in lake and reservoirs. U.S. EPA 440/5/84-001: 277-281.
  27. Kong, K.H., J.H. Lee and K.G. An. 2009. The analysis of water quality and suspended solids effects against transparency of major artificial reservoirs in Korea. Korean Journal of Limnology 42(2): 221-231.
  28. Kwon, Y.H., S.I. Han and J.B. Lee. 2002. Pollution loading in DaeChungHo watershed. Journal of the Korean So-ciety of Water and Watershed 16(5): 581-595.
  29. Lee H.J. and H.K. Lee. 1987. A study on simple phosphorus budget model for Dae Chung Reservoir. Journal of Korean Water Pollution Research Control 3: 17-29.
  30. Lee, H.W., K.G. An and S.S. Park. 2002. Long-term annual trend analysis of epilimnetic water quality and their longitudinal heterogeneities in Lake Soyang. Korean Journal of Limnology 35(1): 36-44.
  31. Lee, J.H. 1999. Management of nonpoint sources in watershed- with reference to Daecheong Reservoir in Korea. Korean Society of Environmental Impact Assessment 9(3): 163-176.
  32. Lee, J.M., J.J. Lee, J.G. Park, J.H. Lee, C.Y. Chang and S.M. Yoon. 2005. Zooplankton fauna and the interrelationship among cladoceran populations and Microcystis aeruginosa (Cyanophyceae) during the cyanobacterial blooming season at Daecheong Lake, South Korea. Korean Journal of Limnology 38(2): 146-159.
  33. Lee, J.W., J.Y. Kim and K.S. Hyun. 2010. Characteristics and correlation of influence factors for eutrophication in Daecheong Lake. Journal of Korean Society of Water Science and Technology 18(4): 39-46.
  34. Lee, M.J., J.W. Choi, H.M. Kim and K.G. An. 2009. Analysis of physical, chemical and biological parameters, based on long-term monitoring (2004-2007), in Daejeon Stream. Korean Journal of Limnology 42(3): 364-373.
  35. Lee, S.H., Y.S. Sin, N.I. Jang, J.M. Kim, H.K. Kim, Y.G. Cho and J. Jeong. 2006. Trophic state and water quality in major lakes of the Sumjin and Youngsan River systems. Korean Journal of Limnology 39(3): 296-309.
  36. Lee, S.J. and K.G. An. 2010. Short-term nutrient enrichment bioassays and nutrient limitation in Daechung Reservoir. Korean Journal of Limnology 43(1): 136-141.
  37. Macan, T.T. 1961. Factors that limit the range of freshwater animals. Biological Reviews 36: 151-198. https://doi.org/10.1111/j.1469-185X.1961.tb01582.x
  38. Macan, T.T. 1974. Freshwater Ecology. John Wiley, NY.
  39. MCT (Ministry of Construction and Transportation). 2001. Long-term plan for water resources. pp. 64-65.
  40. Moss, B. 1980. Ecology of fresh waters, Blackwell Scientific Publications, London.
  41. OECD. 1982. Eutrophication of waters: Monitoring assessment and control OECD. p. 154. Paris.
  42. Oh, K.H. and Y.K. Koh. 2003. Water quality and pollutions of river waters in Gwangju City. Journal of the Environmental Sciences 12(3): 287-297. https://doi.org/10.5322/JES.2003.12.3.287
  43. Oh, Y.T., J.C. Park, D.S. Kim and J.K. Ryu. 2004. Nonpoint pollutants runoff characteristics in Okcheon stream. Journal of Korean Society on Water Quality 20(6): 657- 663.
  44. Park, H.J. and K.G. An. 2007. Trophic State Index (TSI) and empirical models, based on water quality parameters, in Korean Reservoirs. Korean Journal of Limnology 40(1): 14-30.
  45. Park, J.C., J.W. Park, D.H. Kim, J.K. Shin and M.H. Lee. 2005. A comparative study of trophic state in Lake Andong, Korea. Korean Journal of Limnology 38(1): 95-104.
  46. Sakamoto, M. 1966. Primary production by phytoplankton community in some Japanese lakes and its dependence on lake depth. Archieves of Hydrobiologia 62: 1-28.
  47. Sartor, J.D. and S.G. Buchberger. 1997. Partitioning and first flush of metals in urban roadway storm water. Journal of Environmental Engineering, ASCE 123(2): 134- 143. https://doi.org/10.1061/(ASCE)0733-9372(1997)123:2(134)
  48. Shin, J.K., S.J. Hwang and K.J. Cho. 2003. Assessment of water quality in Pyeongtaek Reservoir and its main tributaries. Korean Journal of Limnology 36(1): 38-47.
  49. SPSS. 2009. SPSS 18.0 KOR for windows. Atlanta: Apache Software Foundation.
  50. Thornton, K.W. 1990. Perspectives on reservoir limnology. p. 1-4. In: Reservoir Limnology; ecological perspectives (Thornton, K.W. et al. eds.). John Wiley & Sons, New York.
  51. US EPA. 1976. Water quality criteria research of the U.S. Environmental protection agency. Proceeding of an EPA sponsored symposium, EPA-600 (3-76-079): 185.
  52. Welch, E.B. and T. Lindell. 1992. Nutrient limitation. p. 34- 135. In: Ecological effects of wastewater, 2nd. Chapman and Hall Press, London.
  53. Wetzel, R.G. 2001. Limnology: Lake and river ecosystem (3rd. ed.) Academic Press.
  54. Yeon, I.S., J.Y. Hong, E.Y. Hong and B.J. Lim. 2010. The characteristics and correlation analysis of chlorophyll-a data monitored continuously in Daecheong Reservoir. Journal of Korean Society on Water Quality 26(6): 994- 999.