DOI QR코드

DOI QR Code

기후 스트레스 시나리오에 따른 국내 다목적댐 이수안전도 평가

Assessment of water supply reliability under climate stress scenarios

  • 조지현 (계명대학교 토목공학과) ;
  • 우동국 (계명대학교 토목공학과)
  • Jo, Jihyeon (Department of Civil Engineering, Keimyung University) ;
  • Woo, Dong Kook (Department of Civil Engineering, Keimyung University)
  • 투고 : 2024.01.26
  • 심사 : 2024.06.10
  • 발행 : 2024.06.30

초록

기후변화는 이미 지속 가능한 수자원 관리에 영향을 미치고 있다. 기후변화가 댐 저수지의 물 공급에 미치는 영향은 일반적으로 지구 기후 모델 결과 기반으로 생성된 기후변화 시나리오를 사용하여 수행되고 있다. 그러나 기후변화를 추정하기 때문에 시나리오는 미래에 발생할 수도 있는 상황을 가정하는 한계로 인하여 본질적으로 불확실성을 내포하고 있다. 이러한 문제에 대한 대책으로 의사결정 스케일링 접근법을 본 연구에 적용하였다. 연구대상지는 충주, 용담, 합천, 섬진강 댐이다. 강우 유출 모형(IHACRES)과 HEC-ResSim기반 댐 운영 모형을 결합하여 댐 이수 안전도를 분석하였다. 이 수안전도 분석은 안정적인 댐 운영에 목적을 두고 그 결과에 따라 구조적 또는 비구조적 이수공급 계획을 수립하는데 활용하고 있다. 따라서 본 연구에서는 이수안전도 분석으로 댐이 안전하게 운영될 수 있는지를 평가하고 장래 댐 운영 중 발생할 수 있는 잠재적인 위험을 식별하기 위함이다. 1995년 부터 2014년까지 관측된 강수량과 온도를 기준으로 49개의 기후스트레스 시나리오(분위 수 기준 7개의 강수 시나리오와 0℃부터 6℃도까지 1℃ 간격의 7개의 온도 시나리오)를 적용하였다. 그 결과 홍수기 강우 변동이 비홍수기의 강우 증가보다 수위 상승에 더 큰 변화를 가져왔다. 따라서 이수 안전도는 1분위 강우 의존성이 매우 높은 것으로 평가되었다. 또한 강수 및 온도를 결합한 시나리오에서 댐 용수 공급 신뢰도는 개별 강수 및 온도 시나리오 신뢰도 변화의 합계보다 더 큰 변화가 모의되었다. 이러한 차이는 강수량의 감소와 증가가 각각 물과 에너지가 제한된 증발량의 발생으로 초래하는 것으로 나타났다. 본 연구에서 수행한 의사결정 스케일링을 통한 이수안전도 평가는 댐 운영의 효율성 향상을 도모할 것으로 평가된다.

Climate change is already impacting sustainable water resource management. The influence of climate change on water supply from reservoirs has been generally assessed using climate change scenarios generated based on global climate models. However, inherent uncertainties exist due to the limitations of estimating climate change by assuming IPCC carbon emission scenarios. The decision scaling approach was applied to mitigate these issues in this study focusing on four reservoir watersheds: Chungju, Yongdam, Hapcheon, and Seomjingang reservoirs. The reservoir water supply reliablity was analyzed by combining the rainfall-runoff model (IHACRES) and the reservoir operation model based on HEC-ResSim. Water supply reliability analysis was aimed at ensuring the stable operation of dams, and its results ccould be utilized to develop either structural or non-structural water supply plans. Therefore, in this study, we aimed to assess potential risks that might arise during the operation of reserviors under various climate conditions. Using observed precipitation and temperature from 1995 to 2014, 49 climate stress scenarios were developed (7 precipitation scenarios based on quantiles and 7 temperature scenarios ranging from 0℃ to 6℃ at 1℃ intervals). Our study demonstrated that despite an increase in flood season precipitation leading to an increase in reservoir discharge, it had a greater impact on sustainable water management compared to the increase in non-flood season precipitation. Furthermore, in scenarios combining rainfall and temperature, the reliability of reservoir water supply showed greater variations than the sum of individual reliability changes in rainfall and temperature scenarios. This difference was attributed to the opposing effects of decreased and increased precipitation, each causing limitations in water and energy-limited evapotranspiration. These results were expected to enhance the efficiency of reservoir operation.

키워드

과제정보

본 결과물은 환경부의 재원으로 한국환경산업기술원의 "기후위기대응 홍수방어능력 기술개발사업"의 지원을 받아 연구되었습니다(2022003460002).

참고문헌

  1. Ahn, J.M., Kwon, H.G., Yang, D.S., and Kim, Y.S. (2018). "Assessing environmental flows of coordinated operation of dams and weirs in the Geum River basin under climate change scenarios." Science of The Total Environment, Vol. 643, No. 1, pp. 912-925. https://doi.org/10.1016/j.scitotenv.2018.06.225
  2. Bae, Y.J., Lee, H.J., Jung, B.W., and Jung, H.C. (2020). Korean climate change assessment report 2020. Ministry of Environment.
  3. Brown, C., Ghile, Y., Laverty, M., and Li, K. (2012). "Decision scaling: Linking bottom-up vulnerability analysis with climate projections in the water sector." Water Resources Research, Vol. 48, No. 9, W09537.
  4. Choo, T.H., Kim, Y.K., Kim, Y.S., and Yun, G.S. (2019). "Analysis on dam operation effect and development of an function formula and automated model for estimating suitable site." Journal of Korea Water Resources Association, Vol. 52, No. 3, pp. 187-194. https://doi.org/10.3741/JKWRA.2019.52.3.187
  5. Evan, J.P., and Jakeman, A.J. (1998). "Computation of the instantaneous unit hydrograph and identifiable component flows with application to two small upland catchments." Environmental Modelling & Software, Vol. 13, pp. 385-393.
  6. Hyun, S.H., Kang, B.S., and Kim, J.G. (2016). "Improvement of midand low-flow estimation using variable nonlinear catchment wetness index." Journal of the Korean Society of Civil Engineers, Vol. 36, No. 5, pp. 779-789. https://doi.org/10.12652/Ksce.2016.36.5.0779
  7. Jang, C.H., and Kim, Y.O. (2016). "Improvement of water supply capability of the Nakdong River basin dams with weirs." Journal of the Korean Society of Civil Engineers, Vol. 36, No. 4, pp. 637-644. https://doi.org/10.12652/Ksce.2016.36.4.0637
  8. Jun, S.M., Chung, E.S., Lee, S.H., and Kim, Y.J. (2013). "Development and application of robust decision making technique considering uncertainty of climatic change scenarios." Journal of Korea Water Resources Association, Vol. 46, No. 9, pp. 897-907. https://doi.org/10.3741/JKWRA.2013.46.9.897
  9. Jung, C.M. (2015). A study on runoff projections considering climate change using simple conceptual model. Master Thesis, Graduate School of Engineering, Seoul National University, pp. 124-125.
  10. Jung, H.C., Shin, J.Y., Park, J.H., Yoo, I.S., and Shin, Y.H. (2022). A study on climate risk and adaptation assessment system to prepare mid- to long-term adaptation strategies. Korea Environment Institute, p.38.
  11. Kim, D.H., Choi, S.J., Jang, S.H., and Kang, D.H. (2023a). "Assessment of water supply reliability in the Geum River basin using univariate climate response functions: A case study for changing instreamflow managements." Journal of Korea Water Resources Association, Vol. 56, No. 12, pp. 993-1003.
  12. Kim, J.H., Seo, S.B., and Cho, J.P. (2023b). "Development of a decision scaling framework for drought vulnerability assessment of dam operation under climate change." Journal Korea Water Resources Association, Vol. 56, No. 4, pp. 273-284.
  13. Kim, T.H., and Kang, B.S. (2023). "Climate stress impacts on the reservoir inflows: a decision-scaling and IHACRES modeling approach in South Korean basins." Journal of Water and Climate Change, Vol. 14, No. 9, pp. 3071-3085. https://doi.org/10.2166/wcc.2023.156
  14. Klipsch, J.D., and Hurst, M.B. (2007). HEC-ResSim, reservoir system simulation user's manual. US Army Corps of Engineers, CA, U.S.
  15. Koo, J.H., Yoon, J.T., Sim, K.H., and Cho, H.K. (2015). "A counterfactual for interagency collaboration on water quality: The case of the Geum River basin, South Korea." Water International, Vol. 40, No. 4, pp. 664-688. https://doi.org/10.1080/02508060.2015.1067749
  16. Lee, D.H., Choi, C.W., Yu, M.S., and Yi, J.E. (2012). "Reevaluation of multi-purpose reservoir yield." Journal of Korea Water Resources Association, Vol. 45, No. 4, pp. 361-371. https://doi.org/10.3741/JKWRA.2012.45.4.361
  17. Lee, E.K., Lee, S.M., Ji, J.W., Yi. J.E., and Jung, S.C. (2022). "Estimating the water supply capacity of Hwacheon reservoir for multi-purpose utilization." Journal of Korea Water Resources Association, Vol. 55, No. 6, pp. 437-446.
  18. Lee, J.N., and Noh, J.K. (2015). "Evaluating future stream flow by operation of agricultural reservoir group considering the RCP 8.5 climate change scenario." Journal of the Korean Society of Agricultural Engineers, Vol. 57, No. 5, pp. 113-122.
  19. No, S.H., Jung, K.S., Park, J.H., and Ryoo, K.S. (2013). "Water supply change outlook for Geum River basin considering RCP climate change scenario." Journal of the Korea Water Resources Association, Vol. 46, No. 5, pp. 505-517. https://doi.org/10.3741/JKWRA.2013.46.5.505
  20. Park, J.Y., and Kim, S.J. (2014). "Potential impacts of climate change on the reliability of water and hydropower supply from a multipurpose dam in South Korea." Journal of the American Water Resources Association, Vol. 50, No. 5, pp. 1273-1288. https://doi.org/10.1111/jawr.12190
  21. Park, Y.H., and Yoo, C.S. (2008). "Evaluation of stream flow data observed in the Pyungchang River basin using the IHACRES model." Journal of The Korean Society of Hazard Mitigation, Vol. 8, No. 4, pp. 123-133.
  22. Woo, D.K., Jo, J.H, Kang, B.S, Lee, S.H, Lee, G.R, and Noh, S.J. (2023). "Assessing the sensitivity of runoff projections under precipitation and temperature variability using IHACRES and GR4J lumped runoff-rainfall models." Journal of Civil and Environmental Engineering Research, Vol. 43, No. 1, pp. 43-54.