DOI QR코드

DOI QR Code

Sensitivity Analysis of Sediment Transport Scaling Factors on Cross-Shore Beach Profile Changes using Deflt3D

해빈 단면의 지형변화 모의를 위한 Delft3D 내의 표사이동 관련 매개변수의 민감도 분석

  • Yang, Jung-A (Research Institute for Mega Construction, Korea University) ;
  • Son, Sangyoung (School of Civil, Environment & Architectural Engineering, Korea University)
  • 양정아 (고려대학교 초대형건설기술연구소) ;
  • 손상영 (고려대학교 건축사회환경공학부)
  • Received : 2019.11.18
  • Accepted : 2019.12.26
  • Published : 2019.12.31

Abstract

In this study, sensitivity analysis of sediment transport scaling factors in Delft3D-Morphology was performed to examine the effect those parameters on simulation results of cross-shore profile changes. For numerical experiments, one-year wave time series data which were observed in 2018 on the Maengbang coast in Gangwon prefecture were applied as external force. Bathymetric data observed in January and October of the same year were used as initial bathymetric data and annual bathymetric change data, respectively. The simulation performance of the model was evaluated based on the Brier Skill Score index for each part by dividing an arbitrary cross section within the calculation domain into the onshore and offshore parts. As a result, it was found thet the fBED variable has a slight effect on the simulation results. The fBEDW and fSUSW variables show good simulation performance in onshore part when the value less than 0.5 is applied and vice versa. Among the experimental conditions, the optimal combinations of variables are fBED = 1.0, fBEDW = 1.0, fSUSW = 0.1 for the onshore region and fBED = 1.0, fBEDW = 1.0, fSUSW = 0.5 for the offshore region. However, since these combinations were derived based on the observation data on Maengbang beach in 2018, users should be careful when applying those results to other areas.

본 연구에서는 강원도 맹방해변을 대상으로 Delft3D 지형변화모듈 내의 표사이동 관련 매개변수(fBED, fBEDW, fSUSW)가 지형변화 모의 결과에 미치는 영향을 검토하였다. 맹방해변 해역에서 2018년도에 관측한 1년 간의 파랑자료를 외력으로 적용하고, 동년도 1월과 10월에 관측한 수심자료는 각각 초기 지형자료와 년간 지형변화 자료로 사용하였다. 모델의 지형변화 모의성능은 계산영역 내의 임의의 한 단면을 연안역과 외해역 구간으로 구분하고, 각 영역에 대해 Brier Skill Score 지표에 근거하여 평가하였다. 그 결과 fBED 변수가 지형변화 모의 결과에 미치는 영향은 미약하다는 것을 알 수 있었다. fBEDW와 fSUSW 변수는 그 값이 0.5 이하일 때는 연안역에 대해 좋은 모의 성능을 보이고, 반대의 경우에는 외해역에 대해 좋은 성능을 보이는 것으로 나타났다. 실험조건 중 연안역에 대해 가장 좋은 성능을 보인 변수 조합은 fBED = 1.0, fBEDW = 1.0, fSUSW = 0.1이고, 외해역에 대해서는 fBED = 1.0, fBEDW = 1.0, fSUSW = 0.5이었다. 그러나, 이 조합은 맹방해변 2018년도 자료에 근거하여 산출된 값이므로, 타해역에 적용할 때는 주의가 필요할 것으로 판단된다.

Keywords

References

  1. Booij, N.R.R.C., Ris, R.C. and Holthuijsen, L.H. (1999). A thirdgeneration wave model for coastal regions: 1. Model description and validation. J. Geophys. Res. Oceans, 104(C4), 7649-7666. https://doi.org/10.1029/98JC02622
  2. Briere, C., Giardino, A. and van der Werf, J.J. (2011). Morphological modeling of bar dynamics with DELFT3D: the quest for optimal free parameter settings using an automatic calibration technique. Proceedings of 32th Conference of Coastal Engineering, ACSE, Shanghai, China, 60.
  3. Broekema, Y.B., Giardino, A., van der Werf, J.J., van Rooijen, A.A., Vousdoukas, M.I. and van Prooijen, B.C. (2016). Observations and modeliing of nearshore sediment sorting processes along a barred beach profile. Coastal Engineering, 118, 50-62. https://doi.org/10.1016/j.coastaleng.2016.08.009
  4. Cho, M., Yoon, H.-D., Do, K., Son, S. and Kim, I. (2019). Comparative study on the numerical simulation of bathymetric changes under storm condition. The 3rd International Water Water Safety Symposium. Journal of Coastal Research, Special Issue, 91, 106-110. https://doi.org/10.2112/SI91-022.1
  5. Deltares (2018a). Delft3D-FLOW User Manual: Simulation of multi-dimensional hydrodynamic flows and transport phenomena, including sediments. The Netherlands.
  6. Deltares (2018b). Delft3D-WAVE User Manual: Simulation of short-crested waves with SWAN. The Netherlands.
  7. Hasselaar (2012). Development of a generic automated instrument for the calibration of morphodynamic Delft3D model application. Master's Thesis, Delft University of Technology and National University of Singapore.
  8. Kim M., Son, D. and Yoo, J. (2018). Analysis of seasonal morphodynamic patterns using delft3D in Anmok Coast. Journal of Coastal Disaster Prevention, 5(4), 183-192 (in Korean with English abstract). https://doi.org/10.20481/kscdp.2018.5.4.183
  9. Lesser, G.R., Roelvink, J.A., van Kester, J.A.T.M. and Stelling, G.S. (2004). Development and validation of a three-dimensional morphological model. Coast. Eng., 51, 883-915. https://doi.org/10.1016/j.coastaleng.2004.07.014
  10. Ministry of Oceans and Fisheries (2016). 2016 Coastal Improvement Project Manual (in Korean).
  11. Ministry of Oceans and Fisheries (2018a). Development of Coastal Erosion Prevention Technology (in Korean).
  12. Ministry of Oceans and Fisheries (2018b). K-CoSMoS Guideline (in Korean).
  13. Ruessink, B.G., Kuriyama, Y., Reniers, A.J.H.M., Roelvink, J.A. and Walstra, D.J.R. (2007). Modeling cross-shore sandbar behaviour on the timescale of weeks. Journal of Geophysical Research, 112, 1-15.
  14. Ruggiero, P., Walstra, D.J.R., Gelfenbaum, G. and van Ormondt, M. (2009). Seasonal-scale nearshore morphological evolution: field observations and numerical modeling. Coast. Eng., 56, 1153-1172. https://doi.org/10.1016/j.coastaleng.2009.08.003
  15. Trouw, K., Zimmermann, N., Mathys, M., Delgado, R. and Roelvink, D. (2012). Numerical modelling of hydrodynamics and sediment transport in the surf zone: A sensitivity study with different types of numerical models. Proceedings of 33rd Conference of Coastal Engineering, ACSE, Santander, Spain.
  16. van Duin, M.J.P., Wiersma, N.R., Walstra, D.J.R., van Rijn, L.C. and Stive M.J.F. (2004). Nourishing the shoreface: observations and hindcasting of the Egmond case, The Netherlands. Journal of Coastal Engineering, 51, 813-837. https://doi.org/10.1016/j.coastaleng.2004.07.011
  17. van Rijn, L.C. (1993). Principles of sediment transport in rivers, estuaries and coastal seas. Aqua publications, The Netherlands.
  18. van Rijn, L.C., Walstra, D.J.R., Grasmeijer, B., Sutherland, J., Pan, S. and Sierra, J.P. (2003). The predictability of cross-shore bed evolution of sandy beaches at the time scale of storms and seasons using process-based profile models. Coast. Eng., 47, 295-327. https://doi.org/10.1016/S0378-3839(02)00120-5
  19. van Rijn, L.C., Walstra, D.J.R., van Ormondt, M. (2004). Description of TRANSPOR2004 and implementation in Delft3DONLINE. Final report, Delft hydraulics, The Netherlands.
  20. Walstra, D.J.R., van Ormondt, M. and Roelvink, J.A. (2004). Shoreface nourishment Scenarios, WLlDelft Hydraulics report Z3748.21.
  21. Yoo, J., Swinkels, C. and Do, K. (2016). Numerical simulation winter waves and currents in the Haeundae coast using 2DH Model. Journal of Korean Society of Coastal and Ocean Engineers, 28(6), 350-360. https://doi.org/10.9765/KSCOE.2016.28.6.350