DOI QR코드

DOI QR Code

Water Quality Modeling of the Ara Canal, Using EFDC-WASP Model in Series

3차원 EFDC-WASP 연계모델을 이용한 경인아라뱃길 수질 예측

  • Yin, Zhenhao (Department of Environmental Engineering Chungnam National University) ;
  • Seo, Dongil (Department of Environmental Engineering Chungnam National University)
  • Received : 2013.01.28
  • Accepted : 2013.02.18
  • Published : 2013.03.30

Abstract

Ara Canal is the first artificial canal in Korea that connects the Han River and the Yellow Sea. Due to mixture of waters with different salinity and water quality, complicated hydrodynamic and water quality distributions are expected to occur inside the canal. An integrated hydrodynamic and water quality modeling system was developed using the 3 dimensional hydrodynamic model, EFDC (Environmental Fluid Dynamics Code) and the water quality model WASP (Water Quality Analysis and Simulation Program). According to the modeling results, BOD, TN, TP and Chl-a concentrations inside the canal were lower at the West Gate side than the Han River side since influent concentrations of the West Gate side are significantly lower. Chemical stratification due to salinity difference were more evident at the West Gate side as vertical salinity difference were more pronounced in this area. On the other hand, Chl-a concentrations showed more pronounced vertical distribution at the Han River side as Chl-a concentrations were higher in this area. It was notable that Dissolved Oxygen concentrations can be lower than 2 mg/L occasionally in the middle part of the canal. While major factor affecting DO concentrations in the canal are inflows via both gates, the other important factor was found to be BOD decay in the canal due to extended hydraulic residence time. This study can be used to predict hydrodynamic conditions and water quality in the canal during the year and thus can be helpful in the development of gate operation method of the canal.

경인아라뱃길은 한강하류와 서해를 잇는 국내 첫 인공운하이다. 아라뱃길 내에는 한강갑문으로부터 유입되는 담수와 서해갑문으로부터 유입되는 해수가 혼합됨으로써 염분 분포 및 성층특성이 발달되면서 복잡한 수리동역학적 특성을 나타낼 수 있으며 그에 따라 수질 특성도 크게 영향을 받을 것으로 판단된다. 본 연구에서는 운하 내의 염분 및 수온을 고려하여 3차원적인 수리동역학적 특성을 예측할 수 있는 EFDC (Environmental Fluid Dynamics Code)모델과 이에 따른 수질현상을 고려할 수 있는 WASP (Water Quality Analysis and Simulation Program)모델을 연계하여 사용함으로써 갑문 운영에 따른 3차원 시공간적 수리 및 수질특성을 예측할 수 있는 시스템을 구축하였다. 해수가 유입되는 서해갑문 측의 수질은 대체적으로 양호한 것으로 나타났으나 한강갑문 방향으로 이동할수록 수질은 점점 악화되는 것을 확인할 수 있었다. 또한 봄철 및 가을철에 경인아라뱃길 주운수로 내에서는 DO가 2 mg/L 이하로 감소되는 등 빈 산소층이 형성되었으며, 체류시간 증가에 의한 BOD에 의한 DO소모가 가장 큰 원인으로 작용하는 것으로 추정된다. 따라서 운하 내의 빈산소 현상을 제어하기 위해서 자체적으로 BOD 농도를 개선하기 어려운 경우 수체의 체류시간을 단축시켜서 운영하는 방법을 선택하는 것이 바람직할 것으로 판단된다.

Keywords

References

  1. K-Water, "Environmental Impact Assessment Report; Gyeong- In Canal Project (Navigation Channel Part)," (2009).
  2. Wurbs, R. A., "Water management models: a guide to software," Englewood Cliffs, NJ: Prentice Hall(1995).
  3. Seo, D., Lee, E. H., Lee, J. W. and Kang, E. T., "Application of Water Quality Models to Lakes-Present and Future," in Proceeding of The 24th International Symposium of North American Lake Management Society, Victoria, Canada (2004).
  4. Ambrose, R. B., Jr., Wool, T. A. and Barnwell, T. O., Jr., "Development of Water Quality Modeling in the United States," Environ. Eng. Res., 14(4), 200-210(2009). https://doi.org/10.4491/eer.2009.14.4.200
  5. Seo, D., Lee, E. H. and Reckhow, K., "Development of the CAP Water Quality Model and Its Application to the Geum River, Korea," Environ. Eng. Res., 16(3), 121-129(2011). https://doi.org/10.4491/eer.2011.16.3.121
  6. Di, Toro, D. M., Fitzpatrick, J. J. and Thomann, R. V., Documentation for water quality analysis simulation program (WASP) and model verification program (MVP), Chicago: US Environmental Protection Agency; EPA-600-3-81-044 (1983).
  7. Connolly, J. P. and Winfield, R., "A User's Guide for WASTOX, a Framework for Modeling the Fate of Toxic Chemicals in Aquatic Environments. Part 1: Exposure Concentration. U.S. Environmental Protection Agency," Gulf Breeze, FL, EPA-600/3-84-077(1984).
  8. Ambrose, R, B,, Wool, T. A., Connolly, J. P., Schanz, R. W., "WASP4, a hydrodynamic and water quality model: model theory, user's manual and programmer's guide," Chicago: US Environmental Protection Agency Report; EPA/600/3- 87/039.Athens, GA(1988).
  9. Ambrose, R. B., Wool, T. A, Martin, J. L., "The water quality analysis simulation program, WASP5 part A: model documentation," US Environmental Protection Agency(1993).
  10. Wool, T. A., Ambrose, R. B., Martin, J. L. and Comer, E. A., The Water Quality Analysis Simulation Program, WASP6 User's Manual, USEPA(2001).
  11. Seo, D. I., Choi, J. and Lee, E. H., "Calibration and Clarification of Water Quality Model for Sihwa Lake By Using EUTRO5," J. Kor. Soc. Environ. Eng., 23(1), 131-139 (2001).
  12. Seo, D. I. and Lee, E. H., "Water Quality Modeling of Daechung Lake-Effect of Yongdam Dam," J. Kor. Water Res. Assoc., 35(6), 737-751(2002). https://doi.org/10.3741/JKWRA.2002.35.6.737
  13. Lee, E. H. and Seo, D. I., "Water Quality Modeling of the Keum River-Effect of Yongdam Dam," J. Kor. Water Res. Assoc., 35(5), 525-539(2002). https://doi.org/10.3741/JKWRA.2002.35.5.525
  14. Hamrick, J. M., "A Three-Dimensional Environmental Fluid Dynamics Computer Code; Theoretical and Computational Aspects, The College of William and Mary, Virginia Institute of Marine Science," Special Report, 317, p. 63(1992).
  15. Seo, D. I., "Role and Future of Water Quality Modeling in Korea," ENVITOP Magazine, 12, 32-33(2009).
  16. Tetra Tech, Inc, Hydrodynamic and transport extension to the EFDC model, A report to the U. S. Environmental Protection Agency, Fairfax, VA(2002).
  17. Wool, T. A., S. R. Davie, and H. N. Rodriguez, "Development of Three Dimensional Hydrodynamic and Water Quality Model to Support Total Maximum Daily Load Decision Process for the Neuse River Estuary, North Carolina," Am. Soc. Civil Eng., J. Water Res. Planning Manage., 129(4), 295-306(2003). https://doi.org/10.1061/(ASCE)0733-9496(2003)129:4(295)
  18. Seo, D., Lee, E. H., Lee, J. and Kang, E., "Application of Water Quality Models to Lakes, Present and Future," The 24th International Symposium of North American Lake Management Society, Victoria, British Columbia, Canada, November, 3. 5(2004).
  19. Lee, J. and Seo, D., "Sediment Transport and Water Quality Modeling of Pyeongtaek Reservoir, Korea due to dredging using 3-D Hydrodynamic Model EFDC and WASP 7.0," The 25th International Symposium of North American Lake Management Society (NALMS), Madison, Wisconsin, November, 9. 11(2005).
  20. Seo, D. and Yu, Hana., "Error Analysis of A Steady State Water Quality Model, QUAL2E using A Combination of EFDC-Hydro and WASP7.2," IWA World Water Congress and Exhibition, VIENNA, Austria(2008).
  21. Seo, D. I., Seo, M. J., Koo, M. S. and Woo, J. K., "Serial Use of Hydrodynamic and Water Quality Model of the Geum River using EFDC-Hydro and WASP7.2," J. Kor. Soc. Water and Wastewater, 23(1), 15-22(2009).
  22. Seo, D., Sigdel, R., Kwon, K. H. and Lee, Y. S., "3-D hydrodynamic modeling of Yongdam Lake, Korea using EFDC," Desalination and Water Treatment, 19(1), 1-7(2010). https://doi.org/10.1080/19443994.2010.10513590
  23. Seo, D., and Kim, M., "Application of EFDC and WASP7 in series for Water Quality Modeling of the Yongdam Dam, Korea" J. of Kor. Water Res. Assoc., 44(6), 439-448(2011). https://doi.org/10.3741/JKWRA.2011.44.6.439
  24. Park, J. C., Choi. J .H., Song, Y.I., Song,, S. J. and Seo, D. I., "Water Quality Modeling of Yongdam Dam Reservoir by HSPF, EFDC and WASP," J. Kor. Soc. Environ. Impact Ass., 19(5), 465-473(2010).
  25. Seo, D., Kim, M. and Ahn, J. H., "Prediction of Chlorophyll- a Changes due to Weir Constructions in the Nakdong River Using EFDC-WASP Modelling," Environ. Eng. Res., 17(2), 90-95(2012).
  26. Kim, J. K., Kwak, G. I. and Jeong, J. H., "Three-Dimensional Mixing Characteristics in Seomjin River Estuary," J. Kor. Soc. Mar. Environ. Eng., 11(3), 164-174(2008).
  27. Jung, S. T., Noh, J. W. and Hur, Y. T., "Analysis Saltwater Intrusion using 2-D & 3-D Numerical Model in Seomjin River," Kor. Water Res. Assoc. Res. Meeting Abstract, pp. 785-790(2009).
  28. Son, Y. K., Jeong, S. M., Cha, K. U. and Hur, Y. T., "A Functional Assessment of Nakdong River Barrage for Preventing Salinity Intrusion Using EFDC Model," Kor. Water Res. Assoc. Res. Meeting Abstract, 2018-2022(2009).
  29. Jeon, J. H., Chung, S. W., Park, H. S. and Jang, J. R., "Evaluation of EFDC for the Simulation of Water Quality in Saemangeum Reservoir," J. Kor. Soc. Water Qual., 27(4), 445-460(2011).
  30. Jeon, J. H. and Chung, S. W., "A sensitivity Analysis on Numerical Grid Size of a Three-Dimensional Hydrodynamic and Water Quality model (EFDC) for the Saemangeum Reservoir," J. Kor. Soc. Water Environ., 28(1), 26-37(2012).
  31. Kim, S. J., Seo, D. I. and Ahn, K. H., "Estimation of Proper EFDC Parameters to Improve the Reproductability of Thermal Stratification in Korea Reservoir," J. Kor. Water Res. Assoc., 44(9), 741-752(2011). https://doi.org/10.3741/JKWRA.2011.44.9.741
  32. Ahn, K. H., Seo, D. I. and Kim, S. J, "Development of the Inflow Temperature Regression Model for the Thermal Stratification Analysis in Yongdam Reservoir" J. Kor. Soc. Environ. Impact Ass., 20(4), 435-442(2011).
  33. Yin, Z. H. and Seo, D., Optimum Grid Determination for the Prediction of Salinity Dynamics in the Ara Canal, Korea using 3-D Hydrodynamic Model, EFDC (Environmental Fluid Dynamics Code), paper in preparation.
  34. Tetra Tech, Inc, The Environmental Fluid Dynamics Code User Manual, USEPA Version 1.01(2007).
  35. WASP7.5 homepage. http://www.epa.gov/athens/wwqtsc/html/ wasp.html(2013).
  36. Rossman, L. A., Storm Water Management Model User's Manual Version 5.0, EPA/600/R-05/040(2010).
  37. K-Water, "Environmental Impact Assessment Report; Gyeong- In Canal Project (Gimpo Terminal Part)," (2009).
  38. Korea Ministry of Environment, "Water Information System" www.nier.go.kr
  39. National Fisheries Research and Development Institute, Korea, "National Oceanic Environmental Monitoring System," www.portal.nfrdi.re.kr
  40. Ministry of Construction and Transportation, Korea, "Environmental Impact Assessment Report-Goolpo-Cheon Integrated Flood Management Project," (2004).
  41. Sudokwon Landfill Site Management Cooperation, www.slc. or.kr
  42. Korea Meteorological Administration, www.kma.go.kr
  43. Covar AP, Selecting the Proper Reaeration Coefficient for use in Water Quality Models, Proceeding of the USEPA conference on Environmental Simulation and Modeling, Cincinnati. Ohio(1976).