DOI QR코드

DOI QR Code

Development of river discharge estimation scheme using Monte Carlo simulation and 1D numerical analysis model

Monte Carlo 모의 및 수치해석 모형을 활용한 하천 유량 추정기법의 개발

  • Kang, Hansol (Water Resources Management Research Center, K-water) ;
  • An, Hyunuk (Department of Agricultural and Rural Engineering, Chungnam National University) ;
  • Kim, Yeonsu (Water Resources Management Research Center, K-water) ;
  • Hur, Youngteck (Water Resources Management Research Center, K-water) ;
  • Noh, Joonwoo (Water Resources Management Research Center, K-water)
  • Received : 2022.02.18
  • Accepted : 2022.03.24
  • Published : 2022.04.30

Abstract

Since the frequency of heavy rainfall is increasing due to climate change, water levels in the river exceed past historical records. The rating-curve is to convert water level into flow dicscharge from the regression analysis of the water level and corresponding flow discharges. However, the rating-curve involves many uncertainties because of the limited data especially when observed water level exceed past historical water levels. In order to compensate for insufficient data and increase the accuracy of flow discharge data, this study estimates the flow discharge in the river computed mathematically using Monte Carlo simulation based on a 1D hydrodynamic numerical model. Based on the existing rating curve, a random combination of coefficients constituting the rating-curve creates a number of virtual rating curve. From the computed results of the hydrodynamic model, it is possible to estimate flow discharge which reproduces best fit to the observed water level. Based on the statistical evaluation of these samples, a method for mathematically estimating the water level and flow discharge of all cross sections is porposed. The proposed methodology is applied to the junction of Yochoen Stream in the Seomjin River. As a result, it is confirmed that the water level reproducibility was greatly improved. Also, the water level and flow discharge can be calculated mathematically when the proposed method is applied.

기후변화로 집중호우의 강도가 증가함에 따라 하천에서 기왕의 관측 자료가 없는 고수위가 관측되고 있다. 수위-유량 관계 곡선식은 기왕 관측 자료를 바탕으로 수위를 유량으로 환산하기 때문에 관측 자료가 부족한 경우, 유량 자료 생산에 있어서 불확실성이 커지고 정확성이 떨어지게 된다. 부족한 자료를 보완하고 유량자료의 정확성을 높이기 위하여 본 연구에서는 1차원 수치해석 모형을 기반으로 한 Monte Carlo 모의를 이용하여 대상 지역의 유량을 수리학적으로 추정하는 방법을 제시하였다. 기존에 작성되어있는 수위-유량 관계곡선식을 바탕으로 경사, 조도계수, 하폭 등의 영향을 받는 계수와 흐름의 조건에 따라 영향을 받는 지수를 난수로 발생시켜 다수의 가상 곡선식을 생성하였다. 가상의 곡선식과 주요지점의 관측수위를 활용한 수치모의 결과를 비교하여 홍수위의 재현성이 좋은 최적 샘플의 곡선식을 상류 경계 지점의 곡선식으로 선정하였다. 제안한 방법론을 섬진강 요천 합류부를 대상으로 적용하였으며, 그 결과 수위 재현성이 큰 폭으로 개선된 것을 확인하였다. 또한, 제안한 방법론의 적용 시 해당 샘플의 수리해석 결과를 바탕으로 모의단면의 수위와 유량을 수리학적으로 추정할 수 있다는 장점이 있다.

Keywords

References

  1. Birgir, H., Helgi, S., Solvi, R., Axel, O.J., Rafael, D.V., and Sigurdur, M.G. (2021). "Generalization of the power law rating curve using hydrodynamic theory and Bayesian hierarchical modeling." Landsvirkjun Energy Research Fund, Research Fund of Vegagerdin, Vol. 33, No. 2, e2711. doi: 10.1002/env.2711
  2. Chang, K.H., and Lee, J.H. (2005). "Stage-discharge rating curve model development and modification." Journal of Korea Water Resources Association, Vol. 38, No.4 , pp. 271-280. https://doi.org/10.3741/JKWRA.2005.38.4.271
  3. Cho, Y.D. (2003). The automated program in deriving the stagedischarge curve by applying coefficient of variation, Master Thesis, Chungnam National University, pp. 14-16.
  4. Choo, T.H., and Chae, S.K. (2012). "A study on the estimation of discharge in unsteady condition by using the entropy concept." Journal of the Korea Academia-Industrial cooperation Society, Vol. 13, No. 12, pp. 6159-6166. https://doi.org/10.5762/KAIS.2012.13.12.6159
  5. Di Baldassarre, G., and Montanari, A. (2009). "Uncertainty in river discharge observations: a quantitative analysis." Hydrology and Earth System Science, Vol. 13, No. 6, pp. 913-921. https://doi.org/10.5194/hess-13-913-2009
  6. Hosoda, T., Onda, S., Murakami, T., Iwata, M., Shibayama, Y., and Puay, H.T. (2010) "Flood flow simulation in the case of lack of both upstream and downstream boundary conditions." 17th IAHR-APD Congress and 7th IUWM Conference, IAHR, New Zealand, pp. 1-9.
  7. Jeong, A.C, An, H.U., Kim, Y.S., and Noh, J.W. (2018). "Development of 1D finite volume model for discontinues flow simulation (K-River)", Journal of Korea Water Resources Association, Vol. 51, No. 10, pp. 895-903. https://doi.org/10.3741/JKWRA.2018.51.10.895
  8. Kennedy, E.J. (1984). Discharge Ratings at gaging station. Techniques of water-resources investigations 03-A10, The United States Geological Survey (USGS), Washington, D.C., U.S., pp. 5-7. doi: 10.3133/twri03A10
  9. Kim, J.C., and Paik, K.R. (2015). "Deriving channel width-discharge relationship from remote sensing imagery and digital elevation models." Journal of Korea Water Resources Association, Vol. 48, No. 8, pp. 685-693. https://doi.org/10.3741/JKWRA.2015.48.8.685
  10. Kim, J.S. (2008). Flood risk analysis and development of rainfallstage-discharge curve using monte carlo simulation in urban stream. Ph. D. Dissertation, University of Seoul, pp. 1-141.
  11. Kim, J.S., Yoon, S.K., and Moon, Y.I. (2013). "Development of rating curve for high water level in an urban stream using Monte Carlo simulation." Journal of the Korean Society of Civil Engineers, Vol. 33, No. 4. pp. 1433-1446. doi: 10.12652/Ksce.2013.33.4.1433
  12. Kim, S.E., Shin, J.H., Seo, I.W., and Lyu, S. (2016). "Development of stage-discharge rating curve using hydraulic performance graph model." Procedia Engineering, Vol. 154, pp. 334-339. https://doi.org/10.1016/j.proeng.2016.07.486
  13. Kim, Y.S., Oh, S.R., Lee, S.S., Byun, J.S., and An, H.U. (2021). "Application of stage-fall discharge rating curves to a reservoir based on acoustic doppler velocity meter measurement data." Water 2021, Vol. 13, No. 17, 2443. doi: 10.3390/w13172443
  14. Lambie, J.C. (1978). "Measurement of flowvelocity area methods." Hydrometry: principles and practies, Edited by Herschy, R.W., Wiley, Chichester, UK, pp. 1-52.
  15. Lang, M., Pobanz, K., Renard, B., Renouf, E., and Sauquet, E. (2010). "Extrapolation of rating curves by hydraulic modelling, with application to flood frequency analysis", Hydrological Sciences Journal - Journal des Sciences Hydrologiques, Vol. 55, No. 6, pp. 883-898. https://doi.org/10.1080/02626667.2010.504186
  16. Lee, J.J., and Kwon, H.H. (2010). "A basic study of stagedischarge rating stabilization at the ssang-chi gauging station." Journal of Korean Society of Civil Engineering, Vol. 30, No. 1B, pp. 81-87.
  17. Lee, S.H. (2001). "Determination of Stage-discharge relations by hydraulic channel routing and stage measurement." Journal of Korea Water Resources Association, Vol.34, No. 5, pp. 551-560.
  18. Lee, S.H., and Kang, S.U. (2001). "Stream discharge estimation by hydraulic channel routing and stage measurement." Journal of Korea Water Resources Association, Vol. 34, No. 5, pp. 543-549.
  19. Lee, Y.H., Lee, C.S., and Park, K.B. (2004). "Improvement of ratingcurve by HEC-RAS." Journal of the Environment Sciences, Vol. 13, No. 9, pp. 759-765. https://doi.org/10.5322/JES.2004.13.9.759
  20. Ministry of Land, Infrastructure and Transport (MOLIT) (2003). The basic river plan of the Yocheon River.
  21. Ministry of Land, Infrastructure and Transport (MOLIT) (2021). The basic river plan of the Seomjin River, in press.
  22. Moriasi, D.N., Arnold, J.G., Van Liew, M.W., Bingner, R.L., Harmel, R.D., and Veith, T.L. (2007) "Model evaluation guidelines for Systematic Quantification fo accuracy in watershed simulations." American Society of Agricultural and Biological Engineers, ASABE, Vol. 50, No. 3, pp. 885-900.
  23. Negatu, T.A., Zimale, F.A., and Steenhuis, T.S. (2022). "Establishing Stage - discharge rating curves in developing countries: Lake Tana Basin, Ethiopia." Hydrology, Vol. 9, No. 1, 13. https://doi.org/10.3390/hydrology9010013
  24. Petersen-Overleir, A., and Reitan, T. (2009). "Bayesian analysis of stage-fall-discharge models for gauging stations affected by variable backwater." Hydrological Processes, Vol. 23, No. 21, pp. 3057-3074. https://doi.org/10.1002/hyp.7417
  25. Reitan, T., and Petersen-Overleir, A. (2008). "Bayesian power-law regression with a location parameter, with applications for construction of discharge rating curves." Stochastic Environmental Research and Risk Assessment, Vol. 22, No. 3, pp. 351-365. doi: 10.1007/s00477-007-0119-0