KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
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Evaluation of Levee Reliability by Applying Monte Carlo Simulation

Monte Carlo 기법에 의한 하천제방의 안정성 평가

  • Received : 2006.02.07
  • Accepted : 2006.07.24
  • Published : 2006.09.30
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Abstract

The safety of levee that depends on the river flood elevation has been regarded as very important keys to build up various flood prevention systems. However, deterministic methods for computation of water surface profile cannot reflect the effect of possible inaccuracies in the input parameters. The purpose of this study is to develop a methodology of uncertainty computation of design flood level based on steady flow analysis and Monte Carlo simulation. This study addresses the uncertainty of water surface elevation by Manning's coefficients, design discharges, river cross sections and boundary condition. Monte Carlo simulation with the variations of these parameters is performed to quantify the variations of water surface elevations in a river. The proposed model has been applied to the Kumho-river. The reliability analysis was performed within 38.5 km (95 sections) reach considered the variations of the above-mentioned parameters. Overtopping risks were evaluated by comparing the elevations of the flood condition with the those of the levees. The results show that there is a necessity which will raise the levee elevation between 1 cm and 56 cm at 7 sections. The model can be used for preparing flood risk maps, flood forecasting systems and establishing flood disaster mitigation plans as well as complement of conventional levee design.

홍수범람 수위에 따른 제방의 안전은 홍수방지 시스템 구축에 있어서 매우 중요한 요소이다. 그러나, 기존의 확정론적인 방법을 통한 홍수위의 계산은 입력매개변수들이 내포한 불확실성을 반영할 수 없다. 본 연구의 목적은 Monte Carlo 기법을 활용한 부등류 해석에 의하여, 설계홍수위 불확실도 계산방법의 개발에 있다. 제방의 신뢰도분석 모형에서, 본 연구에서는 Manning 조도계수, 설계유량, 하천의 단면좌표, 기점수위에 의한 홍수위의 불확실성을 고려하였으며, 정량화된 입력매개변수들의 변동성으로부터 하천홍수위의 변동성을 정량화하였다. 본 모형을 대구시를 관류하는 금호강 38.5 km 구간(95개 단면)에 적용하여, 각 단면에서 계산된 홍수위와 기설 제방고의 표고를 비교함으로써 월류 위험도를 분석하였다. 분석 결과, 기설 제방고와 비교하여 7개 단면에서 제방의 증고가 필요할 것으로 판단되었으며, 그 크기는 최소 1 cm에서 최대 56 cm로 계산되었다. 본 연구는 기존의 제방고 설계방법의 보완 및 홍수위험지도 제작, 홍수예측 시스템, 홍수피해완화 계획 설립 등에 활용될 수 있을 것으로 판단된다.

Keywords

References

  1. 감사원(2003) 자연재해 대비실태 감사결과
  2. 건설교통부(1993) 낙동강 하천정비기본계획 보고서(보안III)
  3. 건설교통부(1997) 금호강 하천정비기본계획 보고서
  4. 건설교통부(2002) 하천시설물 설계시 신뢰도 분석 개념 도입에 관한연구
  5. 이을래, 김원, 김상호(2005) 수리학적 인자에 의한 한강에서의 홍수위 영향 분석, 한국수자원학회 논문집, 한국수자원학회, 제38권 2호, pp. 121-131
  6. 이재준, 이정식(1999) 우리나라 도시배수 시스템 설계를 위한 확률강우강도식의 유도, 한국수자원학회 논문집, 한국수자원학회, 제32권 4호, pp. 403-415
  7. 이정규, 전세호(2004) 부정류 모형을 이용한 한강의 수리학적 홍수추적에 관한 연구, 대한토목학회 논문집, 대한토목학회, 제 24권 제4B호, pp. 301-310
  8. 한국수지원학회(2002) 하천설계기준
  9. Cesare, M.A. (1991) First-order analysis of open-channel flow, J. Uydr. Engrg. ASCE, Vol. 117, No. 2, pp. 242-247 https://doi.org/10.1061/(ASCE)0733-9429(1991)117:2(242)
  10. Chiu, C.L. and Lee, T.S. (1972) Reliability and uncertainty in predicting transport processes in natural streams and rivers, Proceedings of the Int. Symp. on Uncertainties in Hydrologic and Water Resour. Systems, Univ. of Arizona, Tucson, Ariz
  11. Chow, V.T. (1959) Open-Channel Hydraulics, McGraw-Hill Book Co
  12. Lehmer, D.H. (1951) Good parameters and implementations for combined multiple recursive random number generators, Operation Research, 47-1 pp. 159-164
  13. Mizumura, K. and Ouazar, D. (1992) Stochastic characteristics of open channel flow Proc. of the Sixth IAHR International Symp. on Stochastic Hydraulics, Taipei, Taiwan, China, pp. 417-423
  14. Muhammad, A. A-Z. (1995) Stochastic Modeling of Unsteady open-Channel Flow, Ph.D. Thesis, Civil Eng. Dept, Colorado State Univ., Fort Collins, Colorado
  15. National Research Council (1995) Flood Risk Management and the American River Basin: An Evaluation. National Academy Press
  16. National Research Council (2000) Risk analysis and uncertainty in flood damage reduction studies. National Academy Press
  17. Oegema, B.W. (1985) Uncertainty Analysis for delineated Flood-plains. Master's Thesis, University of Waterloo, pp. 7-76
  18. Park, S.K. and Miller, K.W. (1988) Random Number Generators : Good Ones are Hard to Find, Communications of the ACM, V. 31. No. 10, pp. 1192-1201 https://doi.org/10.1145/63039.63042
  19. Tung, Y.K. and Mays, L.W. (1980) Risk analysis for hydraulic design, J. of the Hydraulics Division, ASCE, Vol. 106, No. HY5, pp. 893-913
  20. Tung, Y.K. and Yen, B.C. (2005) Hydrosystems Engineering Uncertainty Analysis, McGraw-Hill Publishing Co., N.Y
  21. USACE. (1997) Guidance on Levee Certification for the National Flood Insurance Program, CECW-P/CECW-E, Washington, D.C
  22. Vardeman, S.B. (1994) Statistics of Engineering Problem Solving, PWS Publishing Company, Boston, MA
  23. Wadsworth, H.M. Jr. (1990) Handbook of Statistical Methods for Engineers and Scientists, McGraw-Hill Publishing Co., N. Y
  24. Willis, R., Finney, B.A., Mckee, M., and Militello, A. (1989) Stochastic analysis of estuarine hydraulics: 1. One dimensional steady flow, Stochastic Hydrol. Hyraul, pp. 71-84
  25. Yen, B.C. and Ang, A. H-S. (1971) Risk analysis in design of hydraulic projects, Stochastic hydraulics, Proc. first Inter. Symp., University of Pittsburgh, Pennsylvania, pp. 694-701
  26. Yen, B.C. and Yen, C.Y. (1992) Stochastic perspective of open channel equations, Proc. of the Sixth IAHR International Symp. on Stochastic Hydraulics, taipei, Taiwan, China, pp. 401-407
  27. Xiao-Liang, Yang and Chen-Shen Kung (1994) Parameter Uncertainty in Dam-Break Flood Modeling. River Flood Hydraulics, March, pp. 22-25