DOI QR코드

DOI QR Code

눈 속에서 용질이동을 모사하기 위한 수치모델의 검증

Validations of a Numerical Model of Solute Transport in a Snowpack

  • 이정훈 (극지연구소, 극지지구시스템연구부)
  • 투고 : 2012.08.06
  • 심사 : 2012.10.23
  • 발행 : 2012.10.28

초록

겨울철동안 쌓여 봄에 놓은 눈 녹은 물(snowmelt), 즉 융설의 유출은 북반구 및 산간지역에서 매우 중요한 것으로 여겨지고 있다. 이러한 지역에서 융설로 인한 유동 및 이온의 이동에 대한 이해는 매우 중요하며 전세계적으로 꾸준하게 연구되고 있다. Lee et al. (2008a)와 Lee et al. (2008b)연구에서는 대기로부터 수송된 이온 및 오염원이 융설에 의해 눈속을 이동하는 것을 모사하기 위한 Mobile-Immobile water Model (MIM)을 개발하였다. 이 연구에 사용된 모델을 검증하기 위해서 물질수지계산(mass balance calculation) 및 해석해(analytical solution)를 이용한 모델결과와의 비교를 수행하였다. 일정시간동안 눈 속에서의 물질의 질량변화는 눈 표면에서 들어온 물질과 눈 기저부에서 빠져나간 물질의 질량 차이와 같아야한다는 사실을 이용하여 물질수지를 계산하였다. 파면(wave front)의 이동속도 및 기존문헌에서 알려진 해석 해를 이용하여 모델결과와의 비교도 시도하였다. 모델의 물질수지계산결과 질량 차이가 거의 발생하지 않았으며 모델결과와 해석해와의 비교 역시 두 결과가 거의 일치하였다.

Snowmelt from seasonal snow covers can be significant in many environments of northern and alpine areas. Water flow and chemical transport resulting from snowmelt have been studied for an understanding of contributions to watersheds or catchments. A Mobile-Immobile water Model (MIM) was developed to describe the movement of ionic tracers through a snowpack by Lee et al. (2008a) and Lee et al. (2008b). To validate the model used in the studies, mass balance calculations of the model were conducted and comparisons were made between model results and analytical solutions in this work. Mass balance was calculated based on the fact that change in total mass within a snowpack with time is equal to sum of any change in the flux of water or ionic tracers into and out of the snowpack. Calculations of both water and ionic mass show almost perfect agreement between changes of two water and solute mass fluxes. Comparisons between model results and analytical solutions including wave velocity and effective saturation show almost perfect agreement.

키워드

참고문헌

  1. Feng, X., Kirchner, J.W., Renshaw, C.E., Osterhuber, R.S., Klaue, B. and Taylor, S. (2001) A study of solute transport mechanisms using rare earth element tracers and artificial rainstorms on snow. Water Resources Research, v.37, p.1425-1435. https://doi.org/10.1029/2000WR900376
  2. Harrington, R. and Bales, R.C. (1998) Modeling ionic solute transport in melting snow. Water Resources Research, v.34, p.1727-1736. https://doi.org/10.1029/98WR00557
  3. Hibberd, S. (1984) A model for pollutant concentrations during snow-melt. Journal of Glaciology, v.30, p.58-65. https://doi.org/10.1017/S0022143000008492
  4. Lee, J., Feng, X., Posmentier, E.S., Faiia, A.M., Osterhuber, R. and Kirchner, J.W. (2008a) Modeling of solute transport in snow using conservative tracers and artificial rain-on-snow experiments. Water Resources Research, v.44, W02411, doi:10.1029/2006WR005477.
  5. Lee, J. and Ko, K.S. (2011) An energy budget algorithm for a snowpack-snowmelt calculation. Journal of Soil and Groundwater Environment, v.16, p.82-89. https://doi.org/10.7857/JSGE.2011.16.5.082
  6. Lee, J., Nez, V.E., Feng, X., Kirchner, J.W., Osterhuber, R. and Renshaw, C.E. (2008b) A study of solute redistribution and transport in seasonal snowpack using natural and artificial tracers. Journal of Hydrology, v.357, p.243-254. https://doi.org/10.1016/j.jhydrol.2008.05.004
  7. Meixner, T., Gutmann, C., Bales, R., Leydecker, A., Sickman, J., Melack, J. and McConnell, J. (2004) Multidecadal hydrochemical response of a Sierra Nevada watershed: sensitivity to weathering rate and changes in deposition. Journal of Hydrology, v.285, p.272-285. https://doi.org/10.1016/j.jhydrol.2003.09.005
  8. Rodhe, A. (1998) Snowmelt-Dominated Systems, In: Kendall, C., McDonnell, J.J. (Eds), Isotope Tracers in Catchment Hydrology, Elservier, Amsterdam, p.391-433.
  9. Singh, P., Spitzbart, G., Hübl, H. and Weinmeister, H.W. (1997) Hydrological response of snowpack under rainon- snow events: a field study. Journal of Hydrology, v.202, p.1-20. https://doi.org/10.1016/S0022-1694(97)00004-8
  10. van Genuchten, M.T. and Wierenga, P.J. (1976) Mass transfer studies in sorbing porous media: I. Analytical solution. Soil Science Society of America Journal, v.40, p.473-480. https://doi.org/10.2136/sssaj1976.03615995004000040011x
  11. Wankiewicz, A. (1978) A review of water movement in snow, in Modeling of Snow Runoff, edited by S.C. Colbeck and M. Ray, p.222-252, U.S. Army Cold Region Research and Engineering Laboratory, Hanover, NH.
  12. Williams, M.W., Bales, R.C., Brown, A.D. and Melack, J.M. (1995) Fluxes and transformations of nitrogen in a high-elevation catchment, Sierra Nevada. Biogeochemistry, v.28, p.1-31. https://doi.org/10.1007/BF02178059