Three-Dimensional Numerical Simulation of Impacts of Fault Existence on Groundwater Flow and Salt Transport in a Coastal Aquifer, Buan, Korea

한국 부안 지역 해안 대수층 내의 지하수 유동 및 염분 이동에 대한 단층 존재의 영향 삼차원 수치 모의

  • Park, Ju-Hyun (School of Earth and Environmental Sciences, Seoul National University) ;
  • Kihm, Jung-Hwi (School of Earth and Environmental Sciences, Seoul National University) ;
  • Kim, Han-Tae (Department of Water Resources Research, Korea Institute of Construction Technology) ;
  • Kim, Jun-Mo (School of Earth and Environmental Sciences, Seoul National University)
  • 박주현 (서울대학교 지구환경과학부) ;
  • 김중휘 (서울대학교 지구환경과학부) ;
  • 김한태 (한국건설기술연구원 수자원연구부) ;
  • 김준모 (서울대학교 지구환경과학부)
  • Published : 2008.10.31

Abstract

A series of three-dimensional numerical simulations using a generalized multidimensional hydrodynamic dispersion numerical model is performed to simulate effectively and to evaluate quantitatively impacts of fault existence on densitydependent groundwater flow and salt transport in coastal aquifer systems. A series of steady-state numerical simulations with calibration is performed first for an actual coastal aquifer system which contains a major fault. A series of steadystate numerical simulations is then performed for a corresponding coastal aquifer system which does not have such a major fault. Finally, the results of both numerical simulations are compared with each other and analyzed. The results of the numerical simulations show that the major fault produces hydrogeologically significant heterogeneity and true anisotropy in the actual coastal aquifer system, and density-dependent groundwater flow, salt transport, and seawater intrusion patterns in the coastal aquifer systems are intensively and extensively dependent upon the existence or absence of such a major fault. Especially, the major fault may act as a pathway for groundwater flow and salt transport along the direction parallel to its plane, while it may also behave as a barrier against groundwater flow and salt transport along the direction perpendicular to its plane.

해안 대수층 내의 밀도 의존적 지하수 유동 및 염분 이동에 대한 단층 존재의 영향을 효과적으로 모사하고 정량적으로 평가하기 위하여 하나의 범용 다차원 수리동역학적 분산 수치 모델을 이용한 일련의 삼차원 수치 모델링이 수행되었다. 먼저 단층이 존재하는 실제 해안 대수층에 대해 보정을 병행한 일련의 정상 상태 수치 모델링을 수행한 다음에 이러한 단층이 존재하지 않는 해안 대수층에 대해 일련의 정상 상태 수치 모델링을 수행하여 그 결과를 서로 비교 분석하였다. 수치 모델링 결과는 단층이 실제 해안 대수층 내에 수리지질학적으로 중대한 불균질성과 진이방성을 야기시키며, 해안 대수층 내의 밀도 의존적 지하수 유동 및 염분 이동 그리고 해수 침투 양상이 이러한 단층의 존재 여부에 크게 그리고 광범위하게 좌우됨을 보여준다. 특히 단층은 단층면과 평행한 방향으로는 지하수 유동과 염분 이동에 대해서 통로로 작용하지만, 단층면과 수직한 방향으로는 지하수 유동과 염분 이동에 대해서 방벽으로 작용하는 것으로 해석된다.

Keywords

References

  1. 국립지리원, 1981a, 격포 1:25,000 연안해역기본도, 도엽번호 NI52-1-09-4
  2. 국립지리원, 1981b, 비안도 1:25,000 연안해역기본도, 도엽번호 NI52-1-09-2
  3. 국립지리원, 1997a, 부안 1:5,000 수치지형도, 도엽번호 35607041/51
  4. 국립지리원, 1997b, 위도 1:5,000 수치지형도, 도엽번호 35606049/50/59/60
  5. 김경호, 박재성, 이호진, 연주흠, 2005, 3D-FEMWATER 모델을 이용한 대창지역의 해수침투 범위추정, 한국농공학회논문집, 47(5), 3-13 https://doi.org/10.5389/KSAE.2005.47.5.003
  6. 농업기반공사, 2004, 부안군 농촌지하수관리사업 보고서, 181 p
  7. 농업기반공사, 2005, 2005 해수침투조사 사업 보고서, 461 p
  8. 박남식, 이용두, 1997, 중-동 제주 수역의 지하수 개발로 인한 해수침투, 지하수환경, 4(1), 5-13
  9. 박세창, 윤성택, 채기탁, 이상규, 2002, 서해 연안지역 천부지하수의 수리지구화학: 연안 대수층의 해수 혼입에 관한 연구, 지하수토양환경, 7(1), 63-77
  10. 송성호, 이규상, 용환호, 김진성, 성백욱, 우명하, 2005, 지구통계분석을 이용한 해수침투지역에서의 전기비저항탐사 자료 해석, 제2회 한국물리탐사학회. 대한지구물리학회 공동학술대회 논문집, 한국지질자원연구원, p. 59-64
  11. 심병완, 정상용, 2003, SHARP 모델을 이용한 해안 대수층의 해수침투 경계면 추정, 지하수토양환경, 8(1), 68-74
  12. 심병완, 정상용, 김희준, 성익환, 2002, 수리동역학적 모델링에서 분산지수에 따른 해수침투 범위의 변화, 지하수토양환경, 7(4), 59-67
  13. 한국기상청, 1971-2000, 군산 기상관측소 기후자료, http://www.kma.go.kr
  14. Anderson, M.P., 1979, Using models to simulate the movement of contaminants through groundwater flow systems, Critical Reviews in Environmental Control, 9(2), 97-156 https://doi.org/10.1080/10643387909381669
  15. Bear, J., 1972, Dynamics of Fluids in Porous Media, American Elsevier Publishing Company, New York, 764 p.
  16. Bear, J., Cheng, A.H.D., Sorek. S., Ouaza, D., and Herrera, I. (eds.), 1999, Seawater Intrusion in Coastal Aquifers - Concepts, Methods and Practices, Kluwer Academic Publishers, Dordrecht, Netherlands, 625 p.
  17. Carsel, R.F. and Parrish, R.S., 1988, Developing joint probability distributions of soil water retention characteristics, Water Resources Research, 24(5), 755-769 https://doi.org/10.1029/WR024i005p00755
  18. Cheng, A.H.D. and Ouazar, D. (eds.), 2004, Coastal Aquifer Management: Monitoring, Modeling, and Case Studies, Lewis Publishers, Boca Raton, Florida, 280 p.
  19. Domenico, P.A. and Schwartz, F.W., 1990, Physical and Chemical Hydrogeology, John Wiley and Sons, New York, 824 p.
  20. Essaid, H.I., 1990, A multilayered sharp interface model of coupled freshwater and saltwater flow in coastal systems: Model development and application, Water Resources Research, 26(7), 1431-1454 https://doi.org/10.1029/WR026i007p01431
  21. Fetter, C.W., 1994, Applied Hydrogeology, third edition, Prentice-Hall, Upper Saddle River, New Jersey, 691 p.
  22. Freeze, R.A. and Cherry, J.A., 1979, Groundwater, Prentice Hall, Englewood Cliffs, New Jersey, 604 p.
  23. Frind, E.O., 1982, Simulation of long-term transient density-dependent transport in groundwater, Advances in Water Resources, 5(2), 73-88 https://doi.org/10.1016/0309-1708(82)90049-5
  24. Galeati, G., Gambolati, G., and Neuman, S.P., 1992, Coupled and partially coupled Eulerian-Lagrangian model of freshwaterseawater mixing, Water Resources Research, 28(1), 149-165 https://doi.org/10.1029/91WR01927
  25. Henry, H.R., 1964, Effects of dispersion on salt encroachment in coastal aquifers, In: H.H. Cooper, Jr., F.A. Kohout, H.R. Henry, and R.E. Glover (eds.), Sea Water in Coastal Aquifers, Water-Supply Paper, No. 1613-C, United States Geological Survey, p. C70-C82
  26. Huyakorn, P.S., Andersen, P.F., Mercer, J.W., and White, Jr., H.O., 1987, Saltwater intrusion in aquifers: Development and testing of a three-dimensional finite element model, Water Resources Research, 23(2), 293-312 https://doi.org/10.1029/WR023i002p00293
  27. Hwang, S., Shin, J., Park, I., and Lee, S., 2004, Assessment of seawater intrusion using geophysical well logging and electrical soundings in a coastal aquifer, Youngkwang-gun, Korea, Exploration Geophysics, 35(1), 99-104 https://doi.org/10.1071/EG04099
  28. Jeen, S.W., Kim, J.M., Ko, K.S., Yum, B., and Chang, H.W., 2001, Hydrogeochemical characteristics of groundwater in a mid-western coastal aquifer system, Korea, Geosciences Journal, 5(4), 339-348 https://doi.org/10.1007/BF02912705
  29. Kim, J.H., Kim, R.H., Lee, J., and Chang, H.W., 2003, Hydrogeochemical characterization of major factors affecting the quality of shallow groundwater in the coastal area at Kimje in South Korea, Environmental Geology, 44(4), 478-489 https://doi.org/10.1007/s00254-003-0782-5
  30. Kim, J.M. and Yeh, G.T., 2004, COFAT3D: A Finite Element Model for Fully Coupled Groundwater Flow and Solute Transport in Three-Dimensional Saturated-Unsaturated Porous and Fractured Media, Version 1.0. Technical Report, No. GGEL-2004-12, Geological and Groundwater Engineering Laboratory, School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea, 354 p.
  31. Kim, K., Rajmohan, N., Kim, H.J., Hwang, G.S., and Cho, M.J., 2004, Assessment of groundwater chemistry in a coastal region (Kunsan, Korea) having complex contaminant sources: A Stoichiometric approach, Environmental Geology, 46(6-7), 763-774 https://doi.org/10.1007/s00254-004-1109-x
  32. Kim, R.H., Kim, J.H., Ryu, J.S., and Chang, H.W., 2006, Salinization properties of a shallow groundwater in a coastal reclaimed area, Yeonggwang, Korea, Environmental Geology, 49(8), 1180-1194 https://doi.org/10.1007/s00254-005-0163-3
  33. Klotz, D., Seiler, K.P., Moser, H., and Neumaier, F., 1980, Dispersivity and velocity relationship from laboratory and field experiments, Journal of Hydrology, 45(3-4), 169-184 https://doi.org/10.1016/0022-1694(80)90018-9
  34. Kontis, A.L., 1999, Simulation of Freshwater-Saltwater Interfaces in the Brooklyn-Queens Aquifer System, Long Island, New York, Water-Resources Investigations Report, No. 98-4067, United States Geological Survey, 26 p.
  35. Lee, J.Y. and Song, S.H., 2007a, Evaluation of groundwater quality in coastal areas: Implications for sustainable agriculture, Environmental Geology, 52(7), 1231-1242 https://doi.org/10.1007/s00254-006-0560-2
  36. Lee, J.Y. and Song, S.H., 2007b, Groundwater chemistry and ionic ratios in a western coastal aquifer of Buan, Korea: Implication for seawater intrusion, Geosciences Journal, 11(3), 259-270 https://doi.org/10.1007/BF02913939
  37. Li, Y.H. and Gregory, S., 1974, Diffusion of ions in sea water and in deep-sea sediments, Geochimica et Cosmochimica Acta, 38(5), 703-714 https://doi.org/10.1016/0016-7037(74)90145-8
  38. Misut, P.E. and Voss, C.I., 2007, Freshwater-saltwater transition zone movement during aquifer storage and recovery cycles in Brooklyn and Queens, New York City, USA, Journal of Hydrology, 337(1-2), 87-103 https://doi.org/10.1016/j.jhydrol.2007.01.035
  39. Neuman, S.P., 1990, Universal scaling of hydraulic conductivities and dispersivities in geologic media, Water Resources Research, 26(8), 1749-1758 https://doi.org/10.1029/WR026i008p01749
  40. Park, S.C., Yun, S.T., Chae, G.T., Yoo, I.S., Shin, K.S., Heo, C.H., and Lee, S.K., 2005, Regional hydrochemical study on salinization of coastal aquifers, western coastal area of South Korea, Journal of Hydrology, 313(3-4), 182-194 https://doi.org/10.1016/j.jhydrol.2005.03.001
  41. Parsons, R.W., 1966, Permeability of idealized fractured rock, Society of Petroleum Engineers Journal, 6(2), 126-136 https://doi.org/10.2118/1289-PA
  42. Pinder, G.F. and Cooper, Jr., H.H., 1970, A numerical techniques for calculating the transient position of the saltwater front, Water Resources Research, 6(3), 875-882 https://doi.org/10.1029/WR006i003p00875
  43. Segol, G., Pinder, G.F., and Gray, W.G., 1975, A Galerkin-finite element technique for calculating the transient position of the saltwater front, Water Resources Research, 11(2), 343-347 https://doi.org/10.1029/WR011i002p00343
  44. Snow, D.T., 1968, Rock fracture spacings, openings, and porosities, Journal of the Soil Mechanics and Foundations Division, Proceedings of the American Society of Civil Engineers, 94(SM1), 73-91
  45. Snow, D.T., 1969, Anisotropic permeability of fractured media, Water Resources Research, 5(6), 1273-1289 https://doi.org/10.1029/WR005i006p01273
  46. Song, S.H., Lee, J.Y., and Park, N., 2007, Use of vertical electrical soundings to delineate seawater intrusion in a coastal area of Byunsan, Korea, Environmental Geology, 52(6), 1207-1219 https://doi.org/10.1007/s00254-006-0559-8
  47. van Genuchten, M.Th., 1980, A closed-form equation for predicting the hydraulic conductivity of unsaturated soils, Soil Science Society of America Journal, 44(5), 892-898 https://doi.org/10.2136/sssaj1980.03615995004400050002x
  48. Voss, C.I. and Souza, W.R., 1987, Variable density flow and solute transport simulation of regional aquifers containing a narrow freshwater-saltwater transition zone, Water Resources Research, 23(10), 1851-1866 https://doi.org/10.1029/WR023i010p01851
  49. Yeh, G.T., Cheng, J.R., and Cheng, H.P., 1994, 3DFEMFAT: A 3-Dimensional Finite Element Model of Density-Dependent Flow and Transport through Saturated-Unsaturated Media, Version 2.0, Technical Report, Department of Civil and Environmental Engineering, Pennsylvania State University, University Park, Pennsylvania, USA, 199 p.