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2026 Vol.31, Issue 5 Preview Page

Research Paper

Evaluation of Seawater Intrusion Mitigation by the Ssangcheon Groundwater Dam Using SEAWAT

SEAWAT 수치모의를 통한 쌍천 지하수저류댐의 해수침투 저감 효과 평가

Hyeongyun You1
,
Seonmin Lee2
,
Min-Ho Koo23*
,
Jaeyun Jung4
유 현균1
,
이 선민2
,
구 민호23*
,
정 재윤4
1Cheonghyeon Co., Ltd., Seongnam 13647, Republic of Korea
2Department of Geoenvironmental Sciences, Kongju National University, Gongju 32588, Republic of Korea
3Institute of Earth System Research, Kongju National University, Gongju 32588, Republic of Korea
4DOHWA Engineering Co., Seoul 06178, Republic of Korea
1(주)청현
2공주대학교 지질환경과학과
3공주대학교 지구시스템연구소
4(주)도화엔지니어링
*Corresponding Author
31 October 2026. pp. 18-31
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Abstract

Groundwater dams in coastal aquifers can store freshwater and mitigate seawater intrusion, with performance depending on cutoff-wall continuity and pumping-induced drawdown. This study used a three-dimensional SEAWAT model to examine how cutoff-wall condition and radial collector well (RCW) operation affect seawater intrusion at the Ssangcheon groundwater dam. Thirty-year scenarios evaluated wall conditions, pumping redistribution, and additional RCWs. A complete cutoff wall restricted landward saline migration through the alluvial aquifer, while intrusion persisted through bedrock. Saline groundwater bypassed the wall and underwent upconing near RCW-5, indicating that well location and pumping allocation can be as important as wall continuity. Under the complete-wall condition, shutting down RCW-5 and reallocating its pumping to two inland RCWs reduced simulated salinity at a deep monitoring well by about 42% without changing total pumping. An additional withdrawal of 4,000 m³/d caused a relatively small increase in salinity, whereas withdrawals of 8,000 and 12,000 m³/d progressively expanded the saline zone in bedrock. Because the model lacked independent calibration against depth-specific salinity observations, the findings represent relative responses among scenarios rather than site-specific predictions. Effective groundwater-dam management therefore requires joint consideration of cutoff-wall integrity and spatial pumping allocation.

Keywords
Cutoff wall
Groundwater dam
SEAWAT
Seawater intrusion
Ssangcheon
References
1

Abdalla, O.A.E. and Al-Rawahi, A.S., 2013, Groundwater recharge dams in arid areas as tools for aquifer replenishment and mitigating seawater intrusion: Example of AlKhod, Oman, Environ. Earth Sci., 69(6), 1951-1962.

10.1007/s12665-012-2028-x
2

Abd-Elaty, I., Abd-Elhamid, H.F., and Nezhad, M.M., 2019, Numerical analysis of physical barriers systems efficiency in controlling saltwater intrusion in coastal aquifers, Environ. Sci. Pollut. Res., 26(35), 35882-35899.

10.1007/s11356-019-06725-3
3

Abdoulhalik, A. and Ahmed, A.A., 2017, The effectiveness of cutoff walls to control saltwater intrusion in multi-layered coastal aquifers: Experimental and numerical study, J. Environ. Manage., 199, 62-73.

10.1016/j.jenvman.2017.05.040
4

Apaydin, A. and Zengin, E., 2016, A combined surface and groundwater storage project: The Elmadag dam (Turkey), Q. J. Eng. Geol. Hydrogeol., 49(3), 237-243.

10.1144/qjegh2015-096
5

Booh, S.A., Lee, K.C., Kim, J.S., Jeong, G.C., and Ko, Y.S., 2002, The study on constructing underground wall to prevent seawater intrusion on coastal areas, J. Eng. Geol., 12(2), 215-234 (in Korean with English abstract).

6

Brunner, G.W., 2020, HEC-RAS River Analysis System: Hydraulic Reference Manual, Version 6.0, U.S. Army Corps of Engineers, Hydrologic Engineering Center, Davis, CA.

7

Cho, H.J. and Kim, J.M., 2009, Three-dimensional numerical simulation of impacts of urbanization on groundwater flow and salt transport in a coastal aquifer, Suyeong-Gu, Busan, Korea, J. Soil Groundwater Environ., 14(6), 1-18 (in Korean with English abstract).

8

Dagan, G. and Bear, J., 1968, Solving the problem of local interface upconing in a coastal aquifer by the method of small perturbations, J. Hydraul. Res., 6(1), 15-44.

10.1080/00221686809500218
9

Ferguson, G. and Gleeson, T., 2012, Vulnerability of coastal aquifers to groundwater use and climate change, Nat. Clim. Change, 2(5), 342-345.

10.1038/nclimate1413
10

Hanson, G. and Nilsson, Å., 1986, Ground-water dams for rural-water supplies in developing countries, Ground Water, 24(4), 497-506.

10.1111/j.1745-6584.1986.tb01029.x
11

Im, E.S., Seo, M.W., Kim, H.S., and Shin, D.H., 2005, Evaluation of strength characteristics of soil-cement cutoff-wall materials for groundwater dams, Proceedings of the 2005 Spring Conference of the Korean Society of Soil and Groundwater Environment, Korean Society of Soil and Groundwater Environment, Kongju National University, Gongju, Korea, p.228-231 (in Korean).

12

Khairy, A.T., Al-Ghamdi, A.S., and Gutub, S.A., 2010, Analysis and design of a deep subsurface dam, Int. J. Civ. Environ. Eng. IJCEE-IJENS, 10(3), 27-35.

13

Kim, C.S., Kim, K.S., Bae, D.S., and Song, S.H., 1997, Hydrogeological characteristics of seawater intrusion in the coastal area, J. Korean Soc. Groundw. Environ., 4(2), 61-72 (in Korean with English abstract).

14

Kim, J.T., Chung, I.M., Kim, N.W., and Jeong, G.C., 2011a, Feasibility study of a groundwater dam in Osibcheon, using SWAT-MODFLOW, J. Eng. Geol., 21(2), 179-186 (in Korean with English abstract).

10.9720/kseg.2011.21.2.179
15

Kim, J.T., Kim, G.B., Chung, I.M., and Jeong, G.C., 2014, Analysis of flow duration and estimation of increased groundwater quantity due to groundwater dam construction, J. Eng. Geol., 24(1), 91-98 (in Korean with English abstract).

10.9720/kseg.2014.1.91
16

Kim, J.T., Kim, M.I., Chung, I.M., Kim, N.W., and Jeong, G.C., 2009, An analysis of groundwater level fluctuation caused by construction of groundwater dam, J. Eng. Geol., 19(2), 227-233 (in Korean with English abstract).

17

Kim, N.W., Na, H.N., and Chung, I.M., 2011b, Integrated surface-groundwater hydrologic analysis for evaluating effectiveness of groundwater dam in Ssangcheon watershed, Econ. Environ. Geol., 44(6), 525-532 (in Korean with English abstract).

10.9719/EEG.2011.44.6.525
18

Kim, S.J., 2016, A study on the flow and dispersion in the coastal unconfined aquifer (development and application of a numerical model), J. Korea Water Resour. Assoc., 49(1), 61-72 (in Korean with English abstract).

10.3741/JKWRA.2016.49.1.61
19

Kim, S.J., 2017, Assessment of water resources by the construction of subsurface dam, J. Korea Water Resour. Assoc., 50(11), 795-802 (in Korean with English abstract).

20

Kim, S.Y., Kim, G.B., Park, J.H., and Shin, S.H., 2011c, Effect of underground dam for the prevention of seawater intrusion at the Seom-jin River, J. Korean Geoenviron. Soc., 12(8), 51-57 (in Korean with English abstract).

21

KRC (Korea Rural Community Corporation), 2025, Preliminary Investigation Report for the Repair and Reinforcement of the Ssangcheon No. 1 Groundwater Dam (in Korean).

22

K-water (Korea Water Resources Corporation), 1999, A Study on Artificial Groundwater Recharge and Enlargement of Groundwater Use (in Korean).

23

Langevin, C.D., Thorne, D.T., Jr., Dausman, A.M., Sukop, M.C., and Guo, W., 2008, SEAWAT Version 4: A Computer Program for Simulation of Multi-Species Solute and Heat Transport, U.S. Geological Survey Techniques and Methods, Book 6, Chapter A22, 39 p.

10.3133/tm6A22
24

Lee, S.I. and Kim, B.C., 2003, Site suitability analysis for underground dam using analytic hierarchy process, J. Soil Groundwater Environ., 8(4), 36-44 (in Korean with English abstract).

25

MOCT (Ministry of Construction and Transportation) and K-water (Korea Water Resources Corporation), 2007, Basic Groundwater Investigation Report for the Sokcho-Goseong Area (in Korean).

26

Onder, H. and Yilmaz, M., 2005, Underground dams: A tool of sustainable development and management of groundwater resources, Eur. Water, 11/12, 35-45.

27

Park, C.K., Jeong, G.C., Park, J.H., and Booh, S.A., 2006, Functions and roles of subsurface dam, Water for Future, 39(5), 40-50 (in Korean).

28

Park, H.S., Kihm, J.H., Yum, B.W., and Kim, J.M., 2008, Three-dimensional numerical simulation of impacts of layered heterogeneity and groundwater pumping schemes on seawater intrusion, J. Soil Groundwater Environ., 13(4), 8-21 (in Korean with English abstract).

29

Shim, B.O., Chung, S.Y., Kim, H.J., Sung, I.H., and Kim, B.W., 2002, Characteristics of sea water intrusion using geostatistical analysis of geophysical surveys at the southeastern coastal area of Busan, Korea, J. Soil Groundwater Environ., 7(3), 3-17 (in Korean with English abstract).

30

Sokcho City, 2020, Comprehensive Report on the Basic Investigation and Detailed Design for the Ssangcheon District Disaster Risk Area Improvement Project (in Korean).

31

Talebi, A., Zahedi, E., Hassan, M.A., and Lesani, M.T., 2019, Locating suitable sites for the construction of underground dams using the subsurface flow simulation (SWAT model) and analytical network process (ANP) (case study: Daroongar watershed, Iran), Sustain. Water Resour. Manag., 5(3), 1369-1378.

10.1007/s40899-019-00314-5
32

WCD (World Commission on Dams), 2000, Dams and Development: A New Framework for Decision-Making, Earthscan Publications Ltd., London, UK.

33

Werner, A.D., Bakker, M., Post, V.E.A., Vandenbohede, A., Lu, C., Ataie-Ashtiani, B., Simmons, C.T., and Barry, D.A., 2013, Seawater intrusion processes, investigation and management: Recent advances and future challenges, Adv. Water Resour., 51, 3-26.

10.1016/j.advwatres.2012.03.004
34

Yun, S.H., Park, J.H., and Park, C.K., 2004, A study for reducing sea water intrusion in the ground water dam operation, J. Korea Water Resour. Assoc., 37(2), 97-108 (in Korean with English abstract).

10.3741/JKWRA.2004.37.2.097
Information
  • Publisher :The Korean Society of Soil and Groundwater Environment
  • Publisher(Ko) :한국지하수토양환경학회
  • Journal Title :Journal of Soil and Groundwater Environment
  • Journal Title(Ko) :지하수토양환경
  • Volume : 31
  • No :5
  • Pages :18-31
  • Received Date : 2026-08-05
  • Revised Date : 2026-08-31
  • Accepted Date : 2026-09-21
  • DOI :https://doi.org/10.7857/JSGE.2026.31.5.018
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