DOI QR코드

DOI QR Code

Water quality prediction of inflow of the Yongdam Dam basin and its reservoir using SWAT and CE-QUAL-W2 models in series to climate change scenarios

SWAT 및 CE-QUAL-W2 모델을 연계 활용한 기후변화 시나리오에 따른 용담댐 유입수 및 호내 수질 변화 예측

  • Park, Jongtae (Department of Environmental Engineering, Chungnam National University) ;
  • Jang, Yujin (Department of Environmental Engineering, Chungnam National University) ;
  • Seo, Dongil (Department of Environmental Engineering, Chungnam National University)
  • Received : 2017.07.24
  • Accepted : 2017.09.08
  • Published : 2017.10.31

Abstract

This paper analyzes the impact of two climate change scenarios on flow rate and water quality of the Yongdam Dam and its basin using CE-QUAL-W2 and SWAT, respectively. Under RCP 4.5 and RCP 8.5 scenarios by IPCC, simulations were performed for 2016~2095, and the results were rearranged into three separate periods; 2016~2035, 2036~2065 and 2066~2095. Also, the result of each year was divided as dry season (May~Oct) and wet season (Nov~Apr) to account for rainfall effect. For total simulation period, arithmetic average of flow rate and TSS (Total Suspended Solid) and TP (Total Phosphorus) were greater for RCP 4.5 than those of RCP 8.5, whereas TN (Total Nitrogen) showed contrary results. However, when averaged within three periods and rainfall conditions the tendencies were different from each other. As the scenarios went on, the number of rainfall days has decreased and the rainfall intensities have increased. These resulted in waste load discharge from the basin being decreased during the dry period and it being increased in the wet period. The results of SWAT model were used as boundary conditions of CE-QUAL-W2 model to predict water level and water quality changes in the Yongdam Dam. TSS and TP tend to increase during summer periods when rainfalls are higher, while TN shows the opposite pattern due to its weak absorption to particulate materials. Therefore, the climate change impact must be carefully analyzed when temporal and spatial conditions of study area are considered, and water quantity and water quality management alternatives must be case specific.

본 연구에서는 IPCC가 발간한 AR5 의 시나리오 중 임의로 선택된 RCP 4.5와 RCP 8.5 기후변화 시나리오가 용담댐 유역과 호내의 유량과 수질변화에 미치는 영향을 분석 및 그 방법론을 수립하기 위해서 SWAT 모델과 CE-QUAL-W2 모델을 차례로 사용하였다. 기후변화 시나리오는 용담댐 유역에 대해 상세화 된 자료를 사용하였으며 2016~2095년의 기간을 2016~2035년, 2036~2065년 그리고 2066~2095년의 세 가지의 기간으로 구분하고 또한 각 연도별로 5월과 10월 사이의 우기(Wet Season)와 11월과 4월 사이의 건기(Dry Season)로 또한 구분하여 분석하였다. 전체 모의 기간에 대해 산술평균한 용담댐 유역의 유량과 TSS 및 TP는 RCP 4.5가 RCP 8.5 보다 큰 것으로 나타나고 TN의 경우 다른 경향을 나타내었다. 반면, 모델의 예측결과를 기간별 또는 연중 강우특성별로 구별하여 분석한 경우에는 각 경우마다 서로 다른 결과를 나타내고 있다. 기후변화 시나리오가 진행됨에 따라 전반적으로 강우일수는 감소하고 강우강도는 증가하여 갈수기에는 오염물질의 유출이 감소하고, 홍수기에는 오염물질의 유출이 증가하여 연간 오염물질 유출량이 홍수기에 집중되는 특성을 나타내었다. 상기와 동일한 기간에 대해 SWAT 모델에서 생성된 유역의 자료를 CE-QUAL-W2 모델의 경계조건으로 사용하여 용담댐의 수질변화특성을 모의하였다. TSS와 TP농도는 하절기 강우량의 증가에 따라 특히, 높은 값을 나타내는 것으로 분석되었으나, 고형물질에 잘 흡착되지 않는 TN은 다른 경향이 나타났다. 따라서 기후변화에 의한 장래의 유량 및 수질 변화는 전반적인 경향과 더불어 지역적, 시기적 특성을 또한 반영하여 분석하는 것이 바람직하다고 판단되며 이에 따라 갈수 및 홍수에 의한 시기별, 지역별 유량 및 수질 관리 대책이 별도로 필요할 것으로 판단된다.

Keywords

References

  1. Afshar, A., Kazemi, H., and Saadatpour, M. (2011). "Particle swarm optimization for automatic calibration of large scale water quality model (CE-QUAL-W2): application to Karkheh Reservoir." Water Resources Management, Vol. 25, No. 10, pp. 2613-2632. https://doi.org/10.1007/s11269-011-9829-7
  2. Ahn, S. R., Kim, S. H., Yoon, S. W., and Kim, S. J. (2013). "Evaluation of suspended solids and eutrophication in Chungju Lake using CE-QUAL-W2." Journal of Korea Water Resources Association, Vol. 46, No. 11, pp. 1115-1128. https://doi.org/10.3741/JKWRA.2013.46.11.1115
  3. Bicknell, B. R., Imhoff, J. C., Kittle, Jr. J. L., Jobes, T. H., and Donigan, Jr. A. S. (2001). Hydrologic Simulation Program-Fortran (HSPF) user's manual for version 12. USEPA, National Exposure Research Laboratory, Athens, GA.
  4. Chapra, S. C., Pelletier, G. J., and Tao, H. (2012). QUAL2K: a modeling framework for simulating river and stream water quality version 2.12 documentation and users manual. Civil and Environmental Engineering Dept, Tufts University, Medford, MA.
  5. Chung, S. W., Park, J. H., Kim, Y., and Yoon, S. W. (2007). "Application of CE-QUAL-W2 to Daecheong Reservoir for eutrophication simulation." Journal of the Korean Society on Water Quality, Vol. 23, No. 1, pp. 52-63.
  6. Cole, T. M., and Wells, S. A. (2016). CE-QUAL-W2: a two dimensional, laterally averaged, hydrodynamic and water quality model, version 4.0 user's manual. U.S. Army Corps of Engineer, Vicksburg, MS.
  7. Gabriel, M., Knightes, C., Cooter, E., and Dennis, R. (2016). "Evaluating relative sensitivity of SWAT-simulated nitrogen discharge to projected climate and land cover changes for two watersheds in North Carolina, USA." Hydrological Processes, Vol. 30, No. 9, pp. 1403-1418. https://doi.org/10.1002/hyp.10707
  8. Gassman, P. W., Reyes, M. R., Green, C. H., and Arnold, J. G. (1998). "The soil and water assessment tool: historical development, applications, and future research directions." American Society of Agricultural and Biological Engineers, Vol. 50, No. 4, pp. 1211-1250.
  9. Haith, D. A., Mandel, R., and Wu, R. S. (1992). Generalized watershed loading functions version 2.0 user's manual. Department of Agriculural & Biological Engineering, Corrnell university.
  10. Hamrick, J. M. (1992). A three dimensional environmental fluid dynamics computer code: theoretical and computational aspects. Special Report, The College of William and Mary, Virginia Institute of Marine Science, Glouceslter Point, VA.
  11. IPCC (2014). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Geneva, Switzerland.
  12. Jang, J. H., Yoon, C. G., Jung, K. W., and Lee, S. B. (2009). "Characteristics of pollution loading from Kyongan Stream watershed by BASINS/SWAT." Journal of Ecology and Environment, Vol. 42, No. 2, pp. 200-211.
  13. Jung, S. K. (2000). Modeling of stratification characteristics and water quality dynamics of the Yongdam Lake by using CEQUAL-W2. Master's Thesis, Chungnam National University, Korea, pp. 1-99.
  14. Kim, B. K., Kim, S., Lee, E. T., and Kim, H. S. (2007). "Methodology for estimating ranges of SWAT model parameters: application to Imha Lake inflow and suspended sediments." Journal of the Korean Society of Civil Engineers, Vol. 27, No. 6, pp. 661-668.
  15. Kim, J. Y., and Seo, D. I. (2016). "Reduction of pollutant concentrations in urban stormwater runoff by settling." Journal of Korean Society of Environmental Engineers, Vol. 38, No. 4, pp. 210-218. https://doi.org/10.4491/KSEE.2016.38.4.210
  16. Kim, M. K., Lee, D. H., and Kim, J. (2013). "Development of PRIDE model for high resolution of 1 km in South Korea." Asia-Pacific Journal of Atmospheric Sciences, Vol. 8, No. 1, pp. 13-25.
  17. Korea Meteorological Administration (2014). Korean climate change assessment report 2014.
  18. Lee, E. H., and Seo, D. I. (2011). "Flow calibration and validation of Daechung Lake Watershed, Korea using SWAT-CUP." Journal of Korea Water Resource Association, Vol. 44, No. 9, pp. 711-720. https://doi.org/10.3741/JKWRA.2011.44.9.711
  19. Lee, J. Y., Ha, S. R., Park, I. H., Lee, S. C., and Cho, J. H. (2010). "Characteristics of DOC concentration with storm density flows in a stratified dam reservoir." Water Science and Technology, Vol. 62, No. 11, pp. 2467-2476. https://doi.org/10.2166/wst.2010.537
  20. Lee, K. H. (2014). "Building a nonlinear relationship between air and water temperature for climate-induced future water temperature prediction." Korea Environment Institute, Vol. 13, No. 2, pp. 21-38.
  21. Lee, Y. J., An, S. R., Kang, B., and Kim, S. J. (2008). "Assessment of future climate and land use change on hydology and stream water quality of Anseongcheon watershed using SWAT model (II)." Journal of the Korean Society of Civil Engineers, Vol. 28, No. 6, pp. 665-673.
  22. Park, J. K. (2009). "Application of SWAT model for daily streamflow at the Kum River." Journal of Korea Society of Environmental Administration, Vol. 15, No. 1, pp. 29-36.
  23. Park, M. J., Shin, H. J., Park, G. A., and Kim, S. J. (2010). "Assessment of future hydrological behavior of Soyanggang Dam watershed using SWAT." Journal of the Korean Society of Civil Engineers, Vol. 40, No. 4, pp. 337-346.
  24. Pisinaras, V., Petalas, C., Gikas, G. D., Gemitzi, A., and Tsihrintzis, V. A. (2010). "Hydrological and water quality modeling in a medium-sized basin using the Soil and Water Assessment Tool (SWAT)." Desalination, Vol. 250, No. 1, pp. 274-286. https://doi.org/10.1016/j.desal.2009.09.044
  25. Rossman, L. A., and Huber, W.C. (2016). Storm water management model reference manual. Volume 1, Hydrology (Revised), United States Enviromental Protection Agency Technical Report.
  26. Seo, D., Kim, J. S., and Chang, E. M. (2007). "Application of medium class land cover maps to AVSWAT2000 for the prediction of inflow, CBOD, TN and TP for Yongdam Lake, Korea." Water Science and Technology, Vol. 55, No. 1-2, pp. 513-518. https://doi.org/10.2166/wst.2007.011
  27. Tetra Tech, Inc. (2007). The environmental fluid dynamics code user manual US EPA version 1.01. Fairfax, VA 22030.
  28. US EPA. (2015). BASINS 4.1 (Better Assessment Science Integrating point & Non-point Sources) Modeling Framework. National Exposure Research Laboratory, RTP, North Carolina.
  29. Vandenberg, J. A., Prakash, S., Buchak, E. M. (2015). "Sediment Diagenesis Module for CE-QUAL-W2. Part 1: Conceptual Formulation." Environmental Modeling & Assessment, Vol. 20, No. 3, pp. 239-247. https://doi.org/10.1007/s10666-014-9428-0
  30. Wool, T. A., Ambrose, R. B., Martin, J. L., and Comer, E. A. (2001). The water quality analysis simulation program, WASP6. Part A: model documentation. U.S. Environmental Protection Agency, Center for Exposure Assessment Modeling, Athens, GA.
  31. Yasin, H. Q., and Clemente, R. S. (2014). "Application of SWAT model for hydrologic and water quality modeling in Thachin River Basin, Thailand." Arabian Journal for Science and Engineering, Vol. 39, No. 3, pp. 1671-1684. https://doi.org/10.1007/s13369-013-0770-3
  32. Yi, H. S., Jeong, S. A., Park, S. Y., and Lee, Y. S. (2008). "Modeling study of turbid water in the stratified reservoir using linkage of HSPF and CE-QUAL-W2." Journal of Korean Society of Environmental Engineers, Vol. 30, No. 1, pp. 69-78.
  33. Yi, H. S., Kim, D. S., Hwan, M. H., and An, K. G. (2016). "Assessment of runoff and water temperature variations under RCP climate change scenario in Yongdam dam watershed, South Korea." Journal of Korean Society on Water Environment, Vol. 32, No. 2, pp. 173-182. https://doi.org/10.15681/KSWE.2016.32.2.173
  34. Zhang, Z., Sun, B., and Johnson, B. E. (2015). "Integration of a benthic sediment diagenesis module into the two dimensional hydrodynamic and water quality model - CE-QUAL-W2." Ecological Modelling, Vol. 297, pp. 213-231. https://doi.org/10.1016/j.ecolmodel.2014.10.025