Abstract
Water over-exploitation becomes a common problem in coastal aquifers as it disarranges the dynamic equilibrium of saltwater and freshwater and causes saltwater intrusion (SWI). Mathematical simulations become a necessary tool nowadays to predict SWI under future pumping scenarios. This study aims to assess the validity of sharp-interface approach for an unconfined coastal aquifer subjected to pumping by comparison with sand-tank observation and dispersive approach results. The comparison was in terms of (1) transient movement of saltwater toward the well screen and (2) prediction of well salinity in times. The sharp-interface approach produced acceptable results, although it over-predicted the toe position of saltwater wedge. Salinity of extracted water was less predicted by sharp-interface modeling. The sharp-interface approach was then applied for a synthetic field-scale unconfined aquifer in steady condition with different pumping rates and well placements to explore the sensitivity of the modeling. The results were compared with salinity contours of dispersive modeling. The sharp-interface approach produced better result for higher pumping rates where the saltwater was reached to the well screen. Additionally, the results of fully penetrating wells (compare to partially penetrating one) and also closer location of well to shoreline matched better with the dispersive modeling outputs. In real cases, where the saltwater may wend a long distance toward the well screen, the sharp-interface modeling weakly matched with the dispersive modeling specially in terms of well salinities that is attributed to wider mixing zone.
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References
Abd-Elhamid HF, Javadi AA (2011) A density-dependent finite element model for analysis of saltwater intrusion in coastal aquifers. J Hydrol 401:259–271
Abdollahi-Nasab A, Boufadel MC, Li H, Weaver JW (2010) Saltwater flushing by freshwater in a laboratory beach. J Hydrol 386:1–12
Ataie-Ashtiani B (1998) Contaminant transport in coastal aquifers. PhD thesis, University of Queensland, Brisbane, Australia
Bear J (1979) Hydraulics of groundwater. McGraw-Hill, New York, p 569
Bear J, Dagan G (1964) Moving interface in coastal aquifers. J Hydraul Division 99(HY4):193–215
Cheng AH-D, Halhal D, Naji A, Ouazar D (2000) Pumping optimization in saltwater-intruded coastal aquifers. Water Resour Res 36(8):2155–2165
Dagan G, Bear J (1968) Solving the problem of local interface up-coning in a coastal aquifer by the method of small perturbations. J Hydraul Res 6(1):15–44
Essaid HI (1990) A multilayered sharp-interface model of coupled freshwater and saltwater flow in coastal systems: model development and application. Water Resour Res 16(7):1431–1454
Feseker T (2007) Numerical studies on saltwater intrusion in a coastal aquifer in northwestern Germany. Hydrogeol J 15:267–279
Fetter CW (2001) Applied hydrogeology, 4th edn. Prentice Hall Inc., New Jersey, p 598
Fofonoff NP, Millard Jr RC (1983) Algorithms for computation of fundamental properties of seawater. Unesco technical papers in marine science, p 54
Gemitzi A, Tolikas D (2007) HYDRA model: simulation of salt intrusion in coastal aquifers using Visual Basic and GIS. Environ Modell Softw 22:924–936
Glover RE (1959) The pattern of freshwater flow in a coastal aquifer. J Ground Water Resour 64:439–475
Goswami RR, Clement TP (2007) Laboratory-scale investigation of saltwater intrusion dynamics. Water Resour Res 43:W04418. doi:10.1029/2006WR005151
Guo W, Langevin CD (2002) User’s guide to SEAWAT: a computer program for simulation of three-dimensional variable-density groundwater flow. US Geological Survey Techniques of Water Resources Investigations, Book 6, Chap. A7
Huyakorn PS, Wu YS, Park NS (1996) Multiphase approach to the numerical solution of a sharp-interface saltwater intrusion problem. Water Resour Res 32(1):93–102
Jakovovic D, Werner AD, Simmons CT (2011) Numerical modeling of saltwater up-coning: comparison with experimental laboratory observations. J Hydrol 402:261–273
Johnson AI (1966) Compilation of specific yields for various materials US. Geological Survey Open-File Report, Albuquerque, p 119. http://pubs.usgs.gov/of/1963/0059/
Langevin CD, Thorne Jr DT, Dausman AM, Sukop MC, Guo W (2008) SEAWAT Version 4: a computer program for simulation of multi-species solute and heat transport: US Geological Survey Techniques and Methods, Book 6, Chap. A22, p 39. http://pubs.usgs.gov/tm/tm6a22/
Llopis-Albert C, Pulido-Velazquez D (2014) Discussion about the validity of sharp-interface models to deal with seawater intrusion in coastal aquifers. Hydrol Process 28:3642–3654. doi:10.1002/hyp.9908
Luyun R Jr, Momii K, Nakagawa K (2009) Laboratory-scale saltwater behavior due to subsurface cutoff wall. J Hydrol 377:227–236
Mantoglou A (2003) Pumping management of coastal aquifers using analytical models of saltwater intrusion. Water Resour Res 39:1335. doi:10.1029/2002WR001891.12
Mantoglou A, Papantoniou M (2008) Optimal design of pumping networks in coastal aquifers using sharp interface models. J Hydrol 361:52–63
Mantoglou A, Papantoniou M, Giannoulopoulos P (2004) Management of coastal aquifers based on nonlinear optimization and evolutionary algorithms. J Hydrol 297:209–228
Mehdizadeh SS, Werner AD, Vafaie F, Badaruddin S (2014) Vertical leakage in sharp-interface seawater intrusion models of layered coastal aquifers. J. Hydrol. 519:1097–1107 (Part A)
Motz LH (1992) Salt-water up-coning in an aquifer overlain by a leaky confining bed. Ground Water 30(2):192–198
Ogata A, Banks RB (1961) A solution of the differential equation of longitudinal dispersion in porous media. US Geological Survey Professional Paper 411-A. http://pubs.er.usgs.gov/publication/pp411A
Osman AEA, Abdullah SA (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
Park N, Cui L, Shi L (2009) Analytical design curves to maximize pumping or minimize injection in coastal aquifers. Ground Water 47(6):797–805
Sa da Costa AAG, Wilson JL (1979) A numerical model of seawater intrusion in aquifers. Report vol. 247, R. M. Parsons Laboratory, Massachusetts Institute of Technology, p 245
Sakr SA (1999) Validity of a sharp-interface model in a confined coastal aquifer. Hydrogeol J 7:155–160
Shi L, Cui L, Park N, Huyakorn PS (2011) Applicability of a sharp-interface model for estimating steady-state salinity at pumping wells-validation against sand tank experiments. J Contam Hydrol 124:35–42
Simmons CT, Pierini ML, Hutson JL (2002) Laboratory investigation of variable density flow and solute transport in unsaturated-saturated porous media. Transport Porous Med 47:215–244
Strack ODL (1976) A single-potential solution for regional interface problems in coastal aquifers. Water Resour Res 12:1165–1174
Voss CI, Souza WR (1987) Variable density flow and solute transport simulation of regional aquifers containing a narrow freshwater–seawater mixing zone. Water Resour Res 23:1851–1866
Watson TA, Werner AD, Simmons CT (2010) Transience of seawater intrusion in response to sea level rise. Water Resour Res 46:W12533. doi:10.1029/2010WR009564
Werner AD, Jakovovic D, Simmons CT (2009) Experimental observations of saltwater up-coning. J Hydrol 373:230–241
Werner AD, Ward JD, Morgan LK, Simmons CT, Robinson NI, Teubner MD (2012) Vulnerability indicators of sea water intrusion. Ground Water 50(1):48–58
Zhang Q, Volker RE, Lockington DA (2002) Experimental investigation of contaminant transport in coastal groundwater. Adv Environ Res 6:229–237
Acknowledgments
The experiment part of this research was completed at Flinders University, Adelaide, Australia during visiting research period of the first author. We would like to acknowledge the National Center for Groundwater Research and Training (NCGRT) team for their fund and laboratory facilities. The authors also would like to thank greatly Dr. Adrian Werner for his helps and advices.
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Mehdizadeh, S.S., Vafaie, F. & Abolghasemi, H. Assessment of sharp-interface approach for saltwater intrusion prediction in an unconfined coastal aquifer exposed to pumping. Environ Earth Sci 73, 8345–8355 (2015). https://doi.org/10.1007/s12665-014-3996-9
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DOI: https://doi.org/10.1007/s12665-014-3996-9