Investigation of the Effect of Cutoff Wall on Controlling Seawater Intrusion and Reducing Nitrate Contamination in Coastal Aquifers Using the Meshless Local Petrov–Galerkin (MLPG) Numerical Model

Baazm, Zahra; Akbarpour, Abolfazl; Yaghoobzadeh, Mostafa; Eslamian, Seyed Saeed; Khozeymehnezhad, Hossein

doi:10.22077/jaaq.2025.10092.1126

Document Type : Original Article

Authors

¹ PhD Student, Water Science and Engineering, Faculty of Agriculture, University of Birjand, Birjand, Iran.

² Professor, Department of Civil Engineering, Faculty of Engineering, University of Birjand, Birjand, Iran.

³ Associate Professor, Department of Water Science and Engineering, Faculty of Agriculture, University of Birjand, Birjand, Iran

⁴ Seyed Saeid Eslamian, Department of Water Science and Engineering, College of Agriculture, Isfahan Univetsity of Technology, Isfahan, Iran

⁵ Associate Professor, Department of Water Science and Engineering, Faculty of Agriculture, University of Birjand, Birjand

10.22077/jaaq.2025.10092.1126

Abstract

. Seawater intrusion poses an increasing threat to groundwater resources in coastal regions. Cutoff walls are widely applied to prevent the advancement of seawater wedges. The use of cutoff walls represents an effective engineering strategy for managing and mitigating nitrate contamination in coastal aquifers. The dispersion and transport of contaminants in groundwater resources can render them unusable and exacerbate drought crises in arid and semi-arid regions. Therefore, protecting groundwater resources from the intrusion and accumulation of specific pollutants is essential and necessary. In this study, the effect of a cutoff wall on controlling seawater intrusion and nitrate contamination in coastal aquifers was investigated using the Meshless Local Petrov–Galerkin (MLPG) simulation method. Five scenarios were analyzed, including a case without a cutoff wall and cutoff walls with heights of 15, 30, 45, and 60 meters, in order to evaluate their impact on seawater intrusion and nitrate transport. The results indicated that the reduction ratio of seawater increased continuously and significantly with wall height, rising from about 53.9% at 15 m to more than 82.26% at 60 m. . Cutoff walls can help maintain favorable conditions for nitrate removal by preventing seawater wedge advancement. Hence, considering the effectiveness demonstrated in this study, cutoff walls can be regarded as an efficient and practical engineering approach for reducing seawater intrusion and groundwater contamination.

Keywords

Main Subjects

ًQanat and aquifer

References

Abarca, E., Karam, H., Hemond, H.F. & Harvey, C.F. (2013). Transient groundwater dynamics in a coastal aquifer: the effects of tides, the lunar cycle, and the beach profile. Water Resources Research, 49, 2473–2488. https://doi.org/10.1002/wrcr.20075.

Abdoulhalik, A., Ahmed, A. & Hamill, G.A. (2017). A new physical barrier system for seawater intrusion control. Journal of Hydrology, 549, 416–427. https://doi.org/10.1016/j.jhydrol.2017.04.005

Badaruddin, S. & Mehdizadeh, S.S. (2021). Assessment of Mechanical Dispersion Effects on Mixing Zone under Extreme Saltwater Intrusion. Journal Groundwater for Sustainable Development, 14(15), 100624. https://doi.org/10.1016/j.gsd.2021.100624.

Diersch, H.J. (1988). Finite element modelling of recirculating density-driven saltwater intrusion processes in groundwater. Advances in Water Resources, 11 (1). 25-43, https://doi.org/10.1016/0309-1708(88)90019-X

Ebeling, P., Handel, F. & Walther, M. (2019). Potential of mixed hydraulic barriers to remediate seawater intrusion. Science of the Total Environment, 693, 133478. https://doi.org/10.1016/j.scitotenv .2019.07.284

Guo, Q., Huang, J., Zhou, Z. & Wang, J. (2019). Experiment and Numerical Simulation of Seawater Intrusion under the Influences of Tidal Fluctuation and Groundwater Exploitation in Coastal Multilayered Aquifers. Geofluids, 2019(22), e2316271. https://doi.org/10.1155/2019/2316271

Hughes, JD. & Sanford, WE. (2004). SUTRA-MS: a version of sutra modified to simulate heat and multiple-solute transport. 1207. Open-File Report 1207

Hans, J. & Diersch, G. (2014). Finite element modeling of flow mass and heat transport in porous and fractured media. Springer, https://doi.org/10.1007/978-3-642-38739-5

Ju, X.T., Kou, C.L., Zhang, F.S. & Christie, P., (2006). Nitrogen balance and groundwater nitrate contamination: comparison among three intensive cropping systems on the North China Plain. Environmental Pollution, 143, 117–125. https://doi.org/10.1016/j.envpol.
2005.11.005.

Javadi, A., Hussain, M., Sherif, M. & Farmani, R. (2015). Multi-objective Optimization of Different Management Scenarios to Control Seawater Intrusion in Coastal Aquifers, Water Resources Management, 29:1843–1857, https://doi.org/10.1007/s11269-015-0914-1.

Karim zadeh, E., Akbarpour, A. & Mohtashami, A. (2024). Simulation of sea water infiltration in coastal aquifer using MLPG numerical method. Journal of Aquifer and Qanat, 5(8), 44-19. https://doi.org/10.22077/jaaq.2024.8115.1076. [In Persian].

Kaleris, V.K. & Ziogas, A.I. (2012). The effect of cutoff walls on saltwater intrusion and groundwater extraction in coastal aquifers. Journal of Hydrology . 2013,476, 370–383. https://doi.org/10.1016/ j.jhydrol.2012. 11.007

Kim, K.H., Heiss, J.W., Michael, H.A., Cai, W.J., Laattoe, T., Post, V.E.A. & Ullman, W.J. (2017). Spatial patterns of groundwater biogeochemical reactivity in an intertidal beach aquifer. Journal of Geophysical Research, Biogeosci. 122, 2548–2562. https://doi.org/10.1002/2017JG003943.

Liu, W.K., Jun, S. & Zhang, Y.F. (1995). Mesh free methods. CRC PRESS, Boca Raton, London, NewYork, Washington, D.C.

Luiz, D.S.G.J., Pinto, V.F. & Mannathal, H.V. (2018). Use of electrical resistivity tomography in selection of sites for underground dams in a semiarid region in southeastern Brazil. Groundwater for Sustainable Development, 2018,7, 232–238. https://doi.org/10.1016/j.gsd.2018.06.001.

Luyun, R., Momii, K. & Nakagawa, K. (2011). Effects of recharge wells and flow barriers on seawater intrusion. Ground Water, 49, 239–249. https://doi.org/10.1111/j.1745-6584.2010.00719.x

Lu, C., Xin, P., Kong, J., Li, L. & Luo, J. (2015). Analytical solutions of seawater intrusion in sloping confined and unconfined coastal aquifers. Water Resources Research, 51, 9127–9140. https://doi.org/10.1002/2014WR016259.

Mohtashmi, A. (2016). Use of surface without network in groundwater flow modeling in free streams. MSc dissertation, Faculty of Engineering, University of Birjand, Iran [In Persian].

Omajene, A., Egbai, J., Chucks, O. & Emmanuel Ch. (2024). Investigation of Saltwater Intrusion into Freshwater Aquifers in Some Estuary Environment in Niger Delta, Journal of Water Resources and Ocean Science, 13(4):94-104. https://doi.org/10.11648/j. wros.20241304.11.

Onder, H. & Yilmaz, M. (2005). Underground Dams-A tool of sustainable development and management of groundwater resources. Eur.Water,11(12), 35–45, https://doi.org/10.1016/j.jhydrol.2016.12.012

Provost, A. M. & Voss, CI. (2019). SUTRA-A model for saturated-unsaturated variable-density ground-water flow with solute or energy transport Documentation of Generalized Boundary Conditions, a Modified Implementation of Specified Pressures and Concentrations or Temperatures, and the Lake Capability. Report, 2(4231). https://doi.org/10.3133/tm6A52

Rozell, D.J., Wong, T. (2010). Effects of climate change on groundwater resources at Shelter Island, New York State, USA. Hydrogeol, 18, 1657–1665. https://doi.org/10.1007/s10040-010-0615-z.

Rastogi, A. K. Choi, G. W. & Ukarande, S. K. (2004). Diffused interface model to prevent ingress of seawater in multi-layer coastal aquifers. Journal of Special Hydrology, 1-31.

Werner, A.D. (2017). On the classiﬁcation of seawater intrusion. Journal of Hydrology, 551, 619–631. https://doi.org/10.1016/j.jhydrol.2016.12.012

Sun, Q.G., Zheng, T.Y., Zheng, X.L., Chang, Q.P. & Walther, M. (2019). Inﬂuence of a subsurface cut-off wall on nitrate contamination in an un conﬁned aquifer. Journal of Hydrology. 575, 234–243. https:// doi.org/10.1016/j.jhydrol.2019.05.030

Spiteri, C., Slomp, C.P., Charette, M.A., Tuncay, K. & Meile, C. (2008). Flow and nutrient dynamics in a subterranean estuary (Waquoit Bay, MA, USA): Field data and reactive transport modeling. Geochim. Cosmochim. Acta 72, 3398–3412. https://doi.org/10.1016/j.gca.2008.04.027

Tianyuan, Z., Xilai, Z., Qiguo, S., Lichun W. & Marc, W. (2020). Insights of variable permeability full-section wall for enhanced control of seawater intrusion and nitrate contamination in unconfined aquifers. Journal of Hydrology, 586 (2020) 124831 https://doi.org/10.1016/j.jhydrol.2020.124831.

Watson, T.A., Werner, A.D. & Simmons, C.T. (2010). Transience of seawater intrusion inresponse to sea level rise. Water Resources Research, 46, 1–10. https://doi.org/10.1029/ 2010WR009564.

Walther, M., Graf, T., Kolditz, O., Liedl, R. & Post, V. (2017). How significant is the slope of the sea-side boundary for modelling seawater intrusion in coastal aquifers?. Journal of Hydrology.551, 648–659. https://doi.org/10.1016/j.jhydrol.2017.02.031.

Werner, A.D., Bakker, M., Post, V.E.A., Vandenbohede, A., Lu, C., Ataie-Ashtiani, B., Simmons, C.T. & Barry, D.A. (2013). Seawater intrusion processes, investigation and management: Recent advances and future challenges. Adv. Water Resour. 51, 3–26. https://doi.org/10.1016/j.advwatres.2012.03.004.

Yuan, Y.R.., Liang, D. & Rui, H.X. (2009). Numerical simulation and analysis of 3D seepage mechanics in seawater intrusion prevention project. Sci. China,39, 222–236.

Ye, Yu., Chiogna, G., Cirpka, O., Grathwohl, P. & Rolle, M. (2015). Experimental Investigation of CompoundSpecific Dilution of Solute Plumes in Saturated Porous Media: 2-D vs. 3-D Flow-Through Systems. Journal of Contaminant Hydrology, 172: 33-47,https://doi.org/10.1016/j.jconhyd.2014.11.002

Investigation of the Effect of Cutoff Wall on Controlling Seawater Intrusion and Reducing Nitrate Contamination in Coastal Aquifers Using the Meshless Local Petrov–Galerkin (MLPG) Numerical Model

References

References

Volume 6, Issue 2January 2025Pages 175-198

Volume 6, Issue 2
January 2025
Pages 175-198