Journal of Korea Water Resources Association (한국수자원학회논문집)

Korea Water Resources Association (한국수자원학회)
권호 표지
DOI QR코드

DOI QR Code

Evaluation and complementation of observed flow in the Hancheon watershed in Jeju Island using a physically-based watershed model

유역모형을 활용한 제주도 한천 유역의 관측유량 평가 및 보완

  • Kim, Chul Gyum (Hydro Science and Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology) ;
  • Kim, Nam Won (Hydro Science and Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology)
  • 김철겸 (한국건설기술연구원 수자원하천연구소) ;
  • 김남원 (한국건설기술연구원 수자원하천연구소)
  • Received : 2016.10.07
  • Accepted : 2016.10.27
  • Published : 2016.11.30
Download PDF
⟨ Previous Next ⟩

Abstract

This study was conducted to evaluate observed runoff data collected every 10 minutes at stream gauging stations in Jeju Island using a physically-based model, SWAT. The Hancheon watershed was selected as study area, and ephemeral stream algorithm suggested by previous research was incorporated into the model, which is able to simulate ephemeral runoff pattern of Jeju streams. Simulated runoff and runoff rates were compared to observations during 2008-2013, which showed 'very good' performance rating in Nash-Sutcliffe model efficiency (ME) and determination coefficient ($R^2$). Some observations had problems such that runoff rates were very high for some rainfall events with little amount of antecedent rainfall, and were very low or missing with much rainfall comparing to previous researches. Additionally, regression equation between precipitation and simulated runoff was generated with high degree of correlation. The equation can be utilized to simply predict reasonable runoff, or to investigate and complement the abnormal or missing data of observations on the assumption that modelling results were sufficiently reliable and satisfactory. As results, minimizing the error in calibrating the model by evaluation of observed data would be helpful to accurately model the rainfall-runoff characteristics and analyze the water balance components of watersheds in Jeju Island.

본 연구에서는 제주도의 한천 유역을 대상으로 유역모델링 기법으로 많이 활용되고 있는 SWAT 모형을 이용하여 실시간 관측되고 있는 하천유량의 신뢰성과 활용성을 평가하였다. 평상시 거의 건천의 형태를 나타내는 간헐하천 특성을 고려하기 위하여 기존 연구에서 검증되었던 간헐하천모의 알고리즘을 적용하였으며, 2008~2013년을 대상으로 유역별 관측사상과 모의사상을 비교 분석하였다. 모형효율과 결정계수를 통해 모형 적용성을 평가한 결과, 보정기간에 대해 모형효율(ME) 0.88, 결정계수($R^2$) 0.93, 검증기간에 대해서는 각각 0.79와 0.89로서 매우 양호한 것으로 분석되었다. 모의치와 관측치의 차이가 크게 나타나는 일부 사상들에 대한 검토 결과, 강수량에 비해 관측유출률이 너무 크거나 낮은 경우가 있었는데 이는 기존 호우시 유출률 및 모델링 결과와 비교할 때 관측유량의 계측 및 수위-유량 산정과정에서의 오류의 가능성을 예상할 수 있었다. 이러한 관측유량에 대한 보완을 위해 모의자료를 이용하여 강수량과 유출량 간의 회귀관계를 도출하였으며, 2009~2010년을 대상으로 회귀식을 적용한 결과 유역모델링에 의한 모의유량과 잘 일치하는 것으로 나타났다. 따라서, 모델링 결과가 충분한 신뢰성을 보장한다는 가정 하에, 유도된 회귀식을 활용하여 신뢰성 있는 유출량을 간편하게 예측할 수 있으며, 관측자료의 결측치나 이상치를 즉각적으로 검증하는 데에도 활용될 수 있을 것으로 판단된다. 본 연구에서와 같이 관측자료의 검증 및 결측치에 대한 보완을 통하여 모형 적용시 보정과정에서의 오류를 최소화함으로써 제주도 지역의 독특한 유출 특성을 고려한 정교한 모델링과 물수지 분석에 크게 기여할 수 있을 것으로 판단된다.

Keywords

References

  1. Allen, R. G., Pereira, L. S., Raes, D., and Smith, M. (1998). Crop evapotranspiration: Guidelines for computing crop water requirements (FAO Irrigation and Drainage Paper 56). Food and Agriculture, Organization of the United Nations, Rome, Italy.
  2. Arnold, J. G., Allen, P. M., and Bernhardt, G. (1993). "A comprehensive surface-groundwater flow model." Journal of Hydrology, 142, pp. 47-69. https://doi.org/10.1016/0022-1694(93)90004-S
  3. Chung, I. M., Lee, J., and Kim, N. W. (2015). "Estimation of interception in Cheonmi watershed, Jeju Island." Journal of the Korean Society of Civil Engineers, Vol. 35, No. 4, pp. 815-820. https://doi.org/10.12652/Ksce.2015.35.4.0815
  4. Chung, I. M., Lee, J., Kim, J. T., Na, H., and Kim, N. W. (2011). "Development of threshold runoff simulation method for runoff analysis of Jeju Island." Journal of the Environmental Sciences, Vol. 20, No. 10, pp. 1347-1355. https://doi.org/10.5322/JES.2011.20.10.1347
  5. Han, U. G. (2009). A runoff simulation using SWAT model depending on changes to land use. Thesis for Degree of Master, Jeju National University.
  6. Jeju Development Institute (JDI) (2009). Basic Research on Hydrological and Water Quality Characteristics for Utilization of Stream Runoff. Political Research 2009-11, JDI.
  7. Jeju Development Institute (JDI) (2010). Basic Research on Hydrological and Water Quality Characteristics for Utilization of Stream Runoff. Political Research 2010-3, JDI.
  8. Jeju National University (JNU) (2015). Water cycle analysis and establishment of water resources infrastructure in Jeju Island. Ministry of Land, Infrastructure and Transport & Korea Agency for Infrastructure Technology Advancement, R&D-14CRTI-B056997-05.
  9. Jeju Province and Korea Water Resources Cooperation (KOWACO) (2003). Comprehensive Investigation of Hydrogeology and Groundwater Resources in Jeju Island (III). Jeju Province.
  10. Jeju Special Self-Governing Province (JSSGP) (2013). The water management comprehensive plan for Jeju Special Self-Governing Province (2013-2022).
  11. Jung, W. Y. (2008). Simulation of runoff of rivers in Jeju Island using SWAT model. Thesis for Degree of Master, Jeju National University.
  12. Jung, W. Y., Yang, S. K., and Lee, J. H. (2013). "Characteristics of runoff on urban watershed in Jeju Island, Korea." Journal of Environmental Science International, Vol. 22, No. 5, pp. 555-562. https://doi.org/10.5322/JESI.2013.22.5.555
  13. Kang, M. S., Yang, S. K., Jung, W. Y., and Kim, D. S. (2013). "Characteristics of runoff on southern area of Jeju Island, Korea." Journal of Environmental Science International, Vol. 22, No. 5, pp. 591-597. https://doi.org/10.5322/JESI.2013.22.5.591
  14. Kim, C. G., and Kim, N. W. (2015). "Altitudinal pattern of evapotranspiration and water need for upland crops in Jeju Island." Journal of Korea Water Resources Association, Vol. 48, No. 11, pp. 915-923. https://doi.org/10.3741/JKWRA.2015.48.11.915
  15. Kim, N. W., and Lee, J. E. (2013). "Assessment of actual evapotranspiration in the Hancheon watershed, Jeju Island." Journal of Environmental Science International, Vol. 22, No. 5, pp. 533-542. https://doi.org/10.5322/JESI.2013.22.5.533
  16. Kim, N. W., Chung, I. M., and Na, H. (2013a). "A method of simulating ephemeral stream runoff characteristics in Cheonmicheon watershed, Jeju Island." Journal of Environmental Science International, Vol. 22, No. 5, pp. 523-531. https://doi.org/10.5322/JESI.2013.22.5.523
  17. Kim, N. W., Chung, I. M., and Na, H. (2015). "An integrated water budget analysis of Oedocheon watershed in Jeju Island." Journal of Environmental Science International, Vol. 24, No. 4, pp. 471-480. https://doi.org/10.5322/JESI.2015.24.4.471
  18. Kim, N. W., Chung, I. M., Yoo, S. Y., and Lee, J. (2009). "Analysis on the groundwatger usage in Pyoseon area by using the integrated SWAT-MODFLOW model." Proceedings of the Korea Water Resources Association Conference, pp. 1939-1944.
  19. Kim, N. W., Na, H., and Chung, I. M. (2013b). "Simulation of groundwater variation characteristics of Hancheon watershed in Jeju Island using integrated hydrologic modeling." Journal of Environmental Science International, Vol. 22, No. 5, pp. 515-522. https://doi.org/10.5322/JESI.2013.22.5.515
  20. Kim, N. W., Na, H., Chung, I. M., and Kim, Y. J. (2014). "Empirical formula of delay time for groundwater recharge in the representive watersheds, Jeju Island." Journal of Korea Water Resources Association, Vol. 47, No. 9, pp. 743-752. https://doi.org/10.3741/JKWRA.2014.47.9.743
  21. Kim, N. W., Um, M. J., Chung, I. M., and Heo, J. H. (2012). "Estimating the total precipitation amount with simulated precipitation for ungauged stations in Jeju Island." Journal of Korea Water Resources Association, Vol. 45, No. 9, pp. 875-885. https://doi.org/10.3741/JKWRA.2012.45.9.875
  22. Lee, J. H., Yang, S. K., and Kim, M. C. (2015). "Runoff analysis of climate change scenario in Gangjung basin." Journal of Environmental Science International, Vol. 24, No. 12, pp. 1649-1656. https://doi.org/10.5322/JESI.2015.24.12.1649
  23. Ministry of Land, Transport and Maritime Affairs (MLTMA) (2011). National Comprehensive Water Resources Plan (2011-2020). MLTMA.
  24. Moon, D. C., Jung, K. S., Park, W. B., and Kim, Y. C. (2014). "An evaluation of the flood control effect according to the Hancheon reservoir operation." Journal of Korea Water Resources Association, Vol. 47, No. 2, pp. 107-117. https://doi.org/10.3741/JKWRA.2014.47.2.107
  25. 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 of accuracy in watershed simulations." Transactions of ASABE, Vol. 50, No. 3, pp. 885-900. https://doi.org/10.13031/2013.23153
  26. Nash, J. E., and Sutcliffe, J. V. (1970). "River flow forecasting through conceptual models, Part I - A discussion of principles." Journal of Hydrology, 10, pp. 282-290. https://doi.org/10.1016/0022-1694(70)90255-6
  27. Park, W. B., and Moon, D. C. (2011). "Effects of downstream flood possibility reducing after Han-reservoir operation." Journal of Jeju Development Research, 15, pp. 203-221.
  28. Yang, S. K., Kim, D. S., and Jung W. Y. (2014). "Rainfall-runoff characteristics in a Jeju stream considering antecedent precipitation." Journal of Environmental Science International, Vol. 23, No. 4, pp. 553-560. https://doi.org/10.5322/JESI.2014.4.553