Journal of Korea Water Resources Association (한국수자원학회논문집)

Korea Water Resources Association (한국수자원학회)
권호 표지
DOI QR코드

DOI QR Code

A study on the validation of hydraulic model using lagrangian GPS floater

Lagrangian 전자부자를 이용한 수리모델 검증 방안 연구

  • Lee, Ho Soo (Environmental Engineering, Inje University) ;
  • Lee, Jeong Min (Environmental Engineering, Inje University) ;
  • Han, Eun Jin (National Institute of Environmental Research,) ;
  • Kim, Young Do (Environmental Engineering (Nakdong River Environmental Research Center), Inje University)
  • 이호수 (인제대학교 환경공학과) ;
  • 이정민 (인제대학교 환경공학과) ;
  • 한은진 (국립환경과학원 물환경평가연구과) ;
  • 김영도 (인제대학교 환경공학과(낙동강유역환경연구센터))
  • Received : 2019.10.29
  • Accepted : 2019.11.25
  • Published : 2019.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Various types of numerical modeling techniques are used to predict the behavior of pollutants under various water environmental conditions in the event of a water pollutant accident. Among them, a hydraulic model that can consider water flow characteristics is the most basic and very important. The process of evaluating whether the hydraulic model accurately predicts the applied river characteristics is very important. In the verification of the modeling result, the measuring data are often used in the river. Currently, ADCP and FlowTrackers are widely used to measure the flow velocity of rivers. However, ADCP is not accurate when the depth is less than 0.6 m and also when the ratio of irreversibility near the surface is more than 40%. Futhermore, FlowTracker has a limitation in measuring at high depth and high velocity due to the direct measurement method in rivers. Simuation results, which are validated by these methods, are not reliable for low depth conditions of low flowrate and high velocity conditions of high flowrate. In this study, Lagrangian GPS floaters which measures physical quantity of water according to particle movement is used without the conventional method measured by Eulerian technique. The verification method of the model results was studied by comparing the simulation results of the hydraulic model with the velocities measured using the GPS floaters. When comparing the traveling distance of the GPS floaters with the traveling distance of the LPT simulations, the average error rate was 13.6% on distances, and the average error rate was 3.2% on velocities except for the stagnant section. Therefore, GPS floaters can be used for a correction and verification method of hydraulic model simulations.

수질오염사고 발생시에 다양한 수환경 조건에서의 오염물질의 거동 예측을 위해서 여러 가지 유형의 모델링 기법을 사용하고 있으며, 그 중 물의 흐름특성을 고려할 수 있는 수리모델은 가장 기초가 되면서 전체 모의결과에 있어서 매우 중요하다. 이러한 수리모델은 대상하천의 수리특성을 정확하게 예측하고 있는가를 판단하는 과정이 매우 중요하며, 이와 같은 모델링 결과의 검증에 있어서 실제 하천에서 직접 실측한 결과를 이용한다. 현재 하천의 유속 측정에 있어 ADCP와 FlowTracker를 많이 운영하는데 ADCP는 수심이 0.6 m 이하인 경우와 수면 부근의 측정불가역의 비율이 40% 이상일 때 정확도가 매우 떨어진다. FlowTracker의 경우 도섭을 이용한 측정방식으로 인해 고수심 및 고유속 조건에서 측정에 한계를 가진다. 이러한 방식의 실측값을 통해 검증된 모델은 수심이 낮은 저유량기 모의와 유속이 빠른 고유량기에서의 모의결과를 신뢰할 수 없다. 본 연구에서는 Eulerian 방식으로 측정되는 기존의 방법과 달리 입자의 움직임에 따라 수체의 물리량을 측정하는 Lagrangian 방식의 GPS 전자부자를 이용하였다. GPS 전자부자를 이용해 측정한 유속과 수리모델의 모의결과를 비교하여, 모델결과의 검증 방안에 대하여 연구하였다. GPS 전자부자의 이동거리와 LPT 모델 입자의 이동거리를 비교하였을 때 평균 13.6%의 오차율을 보이며, 구간별 유속 차이에서도 정체구간을 제외하면 평균 3.2%의 오차율을 보였다. 따라서 GPS 전자부자를 이용하여 수리모델의 결과에 대한 보정 및 검증 방안으로 활용이 가능할 것으로 사료된다.

Keywords

References

  1. ISO (1997). "ISO 748: Measurement of liquid flow in open channels-Velocity-area methods." International Standard Organization Technical Report, ISO.
  2. Jang, J.H., Jong, J.H., Mun, H.S., Kim, K.H., and Seo, I.W. (2016). "Mixing analysis of oil spilled into the river by GPS-equipped drifter experiment and numerical modeling." Journal of Korean Society on Water Environment, Vol. 32, No. 3, pp. 243-252. https://doi.org/10.15681/KSWE.2016.32.3.243
  3. Jeon, J.H., and Chung, S.W. (2012). "A sensitivity analysis on numerical grid size of a three-dimensional hydrodynamicand water quality model (EFDC) for the Saemangeum reservoir." Journal of Korean Society on Water Environment, Vol. 28, No. 1, pp. 26-37.
  4. Jeon, J.H., Chung, S.W., Park, H.S., and Jang, J.R. (2011). "Evaluation of EFDC for the simulations of water quality in saemangeum reservoir." Journal of Korean Society on water Environment, Vol. 27, No. 4, pp. 445-460.
  5. Ji, J.Y., Park, S.Y., Lee, G.W., Park G.M., Hwang, S.H., Kim, D.H., and Lee, Y.j. (2013). "Analysis and comparison of flow rate measurements using various discharge measuring instrument and ADCP." Journal of Environmental Science International, Vol. 2, No. 2, pp. 251-257.
  6. Kim, J.M., Kim, S.J., Son, G.S., and Kim, D.S. (2015). "Accuracy analysis of ADCP stationary discharge measurement for unmeasured regions." Journal of Korea Water Resources Asociation, Vol. 34, No. 7, pp. 553-566.
  7. Kim, W., Kim, D.G., Kim, C.Y., Park, E.H., and Lee, C.J. (2008). "ADCP Users Practical Guidance."
  8. Lee, C.J., Kim, D.G., Kim, C.Y., and Kim, W. (2005). "Velocity and discharge measurement using ADCP." Journal of Korea Water Resources Asociation, Vol. 38, No. 10, pp. 81-824.
  9. Lee, C.J., Kim, D.G., Kwon, S.I., and Kim, W. (2010). "Inter-comparison of acuracy of discharge measurement methods-a case study performed in the dalcheon river downstream of the goesan dam-, Journal of Korea Water Resource Association, KWRA, Vol. 43, No. 12, pp. 1039-1050. https://doi.org/10.3741/JKWRA.2010.43.12.1039
  10. Lee, D.J., and Park, Y.K. (2013). "A study on the sediment deposition height computation at gunsan port using EFDC." Journal of Korea Water Resources Asociation, Vol. 46, No. 5, pp. 531-545. https://doi.org/10.3741/JKWRA.2013.46.5.531
  11. Ryu, S.S., Kim, C.Y., and Jung, S.W. (2010). "A comparative study on discharge estimation according to methods of float correction factor." Journal of the Korea Water Resources Association Conference, 2010-05, pp. 1284-1288.
  12. Seo, I.W., Park, I.H., Kim, Y.D., Han, E.J., Choo, M.H., and Mun, H.S. (2013). "Mixing analysis of floating pollutant using lagrangian particle tracking model." Journal of Korean Society on Water Environment, Vol. 29, No. 3, pp. 383-392.
  13. Shin, Y.R., Jang, J.R., Choi, J.H., and Cho, Y.K. (2012). "The comparison of grid resolutions using EFDC in saemangeum reservoir." Journal of Korean Society on Water Environment, KSWE, Vol. 28, No. 5. pp. 646-656.