Verification of experimental saltwater intrusion interface in unconfined coastal aquifers using numerical and analytical solutions


Submitted: 31 March 2023
Accepted: 13 June 2023
Published: 27 September 2023
Abstract Views: 961
PDF: 434
Supplementary Material: 208
Publisher's note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Authors

Saltwater intrusion (SWI) is a widespread environmental problem that poses a threat to coastal aquifers. To address this issue, this research employs both numerical and experimental methods to study saltwater intrusion under the impact of sea level rise and varying freshwater boundary conditions in two homogeneous aquifers. The study compares transient numerical groundwater heads and salt concentrations to experimental results under receding-front and advancing front conditions. In the low permeability aquifer, the root mean square error is 0.33 cm and the R2 is greater than 0.9817. Similarly, in the high permeability aquifer, the root mean square error is 0.92 cm and the R2 is greater than 0.9335. The study also compares the results of ten experimental tests for steady-state saltwater intrusion wedge and toe length with seven different analytical solutions. The experimental results are then compared to these analytical solutions to find the most suitable equation. The Rumer and Harleman equation shows good agreement with experimental saltwater intrusion wedge, while the Anderson equation is a good fit for saltwater intrusion toe length. Overall, this research provides valuable insights into saltwater intrusion in coastal aquifers, and the findings can be used to inform policies and management strategies to mitigate the negative impacts of saltwater intrusion. The investigation shed light on how inland water head and Sea Level Rise (SLR) affect SWI behavior.


Abarca, E., & Clement, T. P. (2009). A novel approach for characterizing the mixing zone of a saltwater wedge. Geophysical Research Letters, 36(6). https://doi.org/10.1029/2008GL036995 DOI: https://doi.org/10.1029/2008GL036995

Abd-Elaty, I., & Zelenakova, M. (2022). Saltwater intrusion management in shallow and deep coastal aquifers for high aridity regions. Journal of Hydrology: Regional Studies, 40, 101026. https://doi.org/10.1016/j.ejrh.2022.101026 DOI: https://doi.org/10.1016/j.ejrh.2022.101026

Abd-Elhamid, H. F., Abd-Elaty, I., & Hussain, M. S. (2020). Mitigation of seawater intrusion in coastal aquifers using coastal earth fill considering future sea level rise. Environmental Science and Pollution Research, 27(18), 23234–23245. https://doi.org/10.1007/s11356-020-08891-1 DOI: https://doi.org/10.1007/s11356-020-08891-1

Abdoulhalik, A., & Ahmed, A. A. (2017). The effectiveness of cutoff walls to control saltwater intrusion in multi-layered coastal aquifers: Experimental and numerical study. Journal of Environmental Management, 199, 62–73. https://doi.org/10.1016/j.jenvman.2017.05.040 DOI: https://doi.org/10.1016/j.jenvman.2017.05.040

Abdoulhalik, A., & Ahmed, A. A. (2018). Transience of seawater intrusion and retreat in response to incremental water-level variations. Hydrological Processes, 32(17), 2721–2733. https://doi.org/10.1002/hyp.13214 DOI: https://doi.org/10.1002/hyp.13214

Abdoulhalik, A., Ahmed, A. A., Abdelgawad, A. M., & Hamill, G. A. (2021). Towards a Correlation between Long-Term Seawater Intrusion Response and Water Level Fluctuations. Water, 13(5), 719. https://doi.org/10.3390/w13050719 DOI: https://doi.org/10.3390/w13050719

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

Anderson, E. I. (2021). Analytical Solutions for Confined and Unconfined Coastal Interface Flow by the Hodograph Method. Water Resources Research, 57(9). https://doi.org/10.1029/2021WR030323 DOI: https://doi.org/10.1029/2021WR030323

Armanuos, A. M., Al-Ansari, N., & Yaseen, Z. M. (2020a). Assessing the Effectiveness of Using Recharge Wells for Controlling the Saltwater Intrusion in Unconfined Coastal Aquifers with Sloping Beds: Numerical Study. Sustainability, 12(7), 2685. https://doi.org/10.3390/su12072685 DOI: https://doi.org/10.3390/su12072685

Armanuos, A. M., Al-Ansari, N., & Yaseen, Z. M. (2020b). Underground Barrier Wall Evaluation for Controlling Saltwater Intrusion in Sloping Unconfined Coastal Aquifers. Water, 12(9), 2403. https://doi.org/10.3390/w12092403 DOI: https://doi.org/10.3390/w12092403

Armanuos, A. M., Ibrahim, M. G., Mahmod, W. E., Takemura, J., & Yoshimura, C. (2019). Analysing the Combined Effect of Barrier Wall and Freshwater Injection Countermeasures on Controlling Saltwater Intrusion in Unconfined Coastal Aquifer Systems. Water Resources Management, 33(4), 1265–1280. https://doi.org/10.1007/s11269-019-2184-9 DOI: https://doi.org/10.1007/s11269-019-2184-9

Brakefield, L. (2008). Physical and Numerical Modeling of Buoyant Groundwater Plumes [Thesis]. https://etd.auburn.edu//handle/10415/1038

Chang, Q., Zheng, T., Chen, Y., Zheng, X., & Walther, M. (2020). Investigation of the elevation of saltwater wedge due to subsurface dams. Hydrological Processes, 34(22), 4251–4261. https://doi.org/10.1002/hyp.13863 DOI: https://doi.org/10.1002/hyp.13863

Chang, Q., Zheng, T., Zheng, X., Zhang, B., Sun, Q., & Walther, M. (2019). Effect of subsurface dams on saltwater intrusion and fresh groundwater discharge. Journal of Hydrology, 576, 508–519. https://doi.org/10.1016/j.jhydrol.2019.06.060 DOI: https://doi.org/10.1016/j.jhydrol.2019.06.060

Chang, S. W., Clement, T. P., Simpson, M. J., & Lee, K.-K. (2011). Does sea-level rise have an impact on saltwater intrusion? Advances in Water Resources, 34(10), 1283–1291. https://doi.org/10.1016/j.advwatres.2011.06.006 DOI: https://doi.org/10.1016/j.advwatres.2011.06.006

Christensen, B., & JR, E. A. (1974). A physical model for prediction and control of saltwater intrusion in the Floridan aquifer. University of Florida. Water Resources Research Center, Gainesville, Fa, 88.

Dang, N. M., Vien, L. N., Tung, N. B., Duong, T. A., & Dang, T. D. (2020). Assessments of Climate Change and Sea Level Rise Impacts on Flows and Saltwater Intrusion in the Vu Gia—Thu Bon River Basin, Vietnam. In N. Trung Viet, D. Xiping, & T. Thanh Tung (Eds.), APAC 2019 (pp. 1367–1374). Springer Singapore. https://doi.org/10.1007/978-981-15-0291-0_185 DOI: https://doi.org/10.1007/978-981-15-0291-0_185

Diersch, H.-J. G. (2013). FEFLOW—Finite Element Modeling of Flow, Mass and Heat Transport in Porous and Fractured Media. In FEFLOW: Finite Element Modeling of Flow, Mass and Heat Transport in Porous and Fractured Media (p. 996). https://doi.org/10.1007/978-3-642-38739-5 DOI: https://doi.org/10.1007/978-3-642-38739-5

Gao, M., Zheng, T., Chang, Q., Zheng, X., & Walther, M. (2021). Effects of mixed physical barrier on residual saltwater removal and groundwater discharge in coastal aquifers. Hydrological Processes, 35(7). https://doi.org/10.1002/hyp.14263 DOI: https://doi.org/10.1002/hyp.14263

Ghyben, B. W. (1888). Nota in verband met de voorgenomen putboring nabij, Amsterdam. The Hague, 21.

Glover, R. E. (1959). The pattern of fresh-water flow in a coastal aquifer. Journal of Geophysical Research, 64(4), 457–459. DOI: https://doi.org/10.1029/JZ064i004p00457

Gossel, W., Sefelnasr, A., & Wycisk, P. (2010). Modelling of paleo-saltwater intrusion in the northern part of the Nubian Aquifer System, Northeast Africa. Hydrogeology Journal, 18(6), 1447–1463. https://doi.org/10.1007/s10040-010-0597-x DOI: https://doi.org/10.1007/s10040-010-0597-x

Goswami, R. R., & Clement, T. P. (2007). Laboratory-scale investigation of saltwater intrusion dynamics. Water Resources Research, 43(4). https://doi.org/10.1029/2006WR005151 DOI: https://doi.org/10.1029/2006WR005151

Guo, Q., Zhang, Y., Zhou, Z., & Zhao, Y. (2020). Saltwater Transport under the Influence of Sea-Level Rise in Coastal Multilayered Aquifers. Journal of Coastal Research, 36(5), 1040. https://doi.org/10.2112/JCOASTRES-D-19-00189.1 DOI: https://doi.org/10.2112/JCOASTRES-D-19-00189.1

Guo, W., & Langevin, C. D. (2002). User’s guide to SEAWAT; a computer program for simulation of three-dimensional variable-density ground-water flow. DOI: https://doi.org/10.3133/ofr01434

Herzberg, A. (1901). Die wasserversorgung einiger Nordseebader. J. Gasbeleucht. Wasserversorg., 44, 842–844.

Hubbert, M. K. (1940). The theory of ground-water motion. The Journal of Geology, 48(8, Part 1), 785–944. DOI: https://doi.org/10.1086/624930

Hussain, M. S., Abd-Elhamid, H. F., Javadi, A. A., & Sherif, M. M. (2019). Management of Seawater Intrusion in Coastal Aquifers: A Review. Water, 11(12), 2467. https://doi.org/10.3390/w11122467 DOI: https://doi.org/10.3390/w11122467

Kashef, A.-A. I. (1983). Harmonizing Ghyben-Herzberg interface with rigorous solutions. Groundwater, 21(2), 153–159. DOI: https://doi.org/10.1111/j.1745-6584.1983.tb00712.x

Ketabchi, H., Mahmoodzadeh, D., Ataie-Ashtiani, B., & Simmons, C. T. (2016). Sea-level rise impacts on seawater intrusion in coastal aquifers: Review and integration. Journal of Hydrology, 535, 235–255. https://doi.org/10.1016/j.jhydrol.2016.01.083 DOI: https://doi.org/10.1016/j.jhydrol.2016.01.083

Ketabchi, H., Mahmoodzadeh, D., Ataie-Ashtiani, B., Werner, A. D., & Simmons, C. T. (2014). Sea-level rise impact on fresh groundwater lenses in two-layer small islands. Hydrological Processes, 28(24), 5938–5953. DOI: https://doi.org/10.1002/hyp.10059

Koussis, A. D., Mazi, K., & Destouni, G. (2012). Analytical single-potential, sharp-interface solutions for regional seawater intrusion in sloping unconfined coastal aquifers, with pumping and recharge. Journal of Hydrology, 416–417, 1–11. https://doi.org/10.1016/j.jhydrol.2011.11.012 DOI: https://doi.org/10.1016/j.jhydrol.2011.11.012

Kuan, W. K., Jin, G., Xin, P., Robinson, C., Gibbes, B., & Li, L. (2012). Tidal influence on seawater intrusion in unconfined coastal aquifers. Water Resources Research, 48(2). https://doi.org/10.1029/2011WR010678 DOI: https://doi.org/10.1029/2011WR010678

Lu, C., Xin, P., Kong, J., Li, L., & Luo, J. (2016). Analytical solutions of seawater intrusion in sloping confined and unconfined coastal aquifers: SEAWATER INTRUSION IN SLOPING COASTAL AQUIFERS. Water Resources Research, 52(9), 6989–7004. https://doi.org/10.1002/2016WR019101 DOI: https://doi.org/10.1002/2016WR019101

Lu, C., Xin, P., Li, L., & Luo, J. (2015). Seawater intrusion in response to sea-level rise in a coastal aquifer with a general-head inland boundary. Journal of Hydrology, 522, 135–140. https://doi.org/10.1016/j.jhydrol.2014.12.053 DOI: https://doi.org/10.1016/j.jhydrol.2014.12.053

Luo, Z., Kong, J., Shen, C., Lu, C., Xin, P., Werner, A. D., Li, L., & Barry, D. A. (2022). Approximate analytical solutions for assessing the effects of unsaturated flow on seawater extent in thin unconfined coastal aquifers. Advances in Water Resources, 160, 104104. https://doi.org/10.1016/j.advwatres.2021.104104 DOI: https://doi.org/10.1016/j.advwatres.2021.104104

Luyun Jr, R., Momii, K., & Nakagawa, K. (2011). Effects of recharge wells and flow barriers on seawater intrusion. Groundwater, 49(2), 239–249. DOI: https://doi.org/10.1111/j.1745-6584.2010.00719.x

Mehdizadeh, S. S., Karamalipour, S. E., & Asoodeh, R. (2017). Sea level rise effect on seawater intrusion into layered coastal aquifers (simulation using dispersive and sharp-interface approaches). Ocean & Coastal Management, 138, 11–18. DOI: https://doi.org/10.1016/j.ocecoaman.2017.01.001

Rumer Jr, R. R., & Harleman, D. R. (1963). Intruded salt-water wedge in porous media. Journal of the Hydraulics Division, 89(6), 193–220. DOI: https://doi.org/10.1061/JYCEAJ.0000954

Sherif, M., Sefelnasr, A., Ebraheem, A. A., & Javadi, A. (2014). Quantitative and Qualitative Assessment of Seawater Intrusion in Wadi Ham under Different Pumping Scenarios. Journal of Hydrologic Engineering, 19(5), 855–866. https://doi.org/10.1061/(ASCE)HE.1943-5584.0000907 DOI: https://doi.org/10.1061/(ASCE)HE.1943-5584.0000907

Shi, W., Lu, C., Ye, Y., Wu, J., Li, L., & Luo, J. (2018). Assessment of the impact of sea-level rise on steady-state seawater intrusion in a layered coastal aquifer. Journal of Hydrology, 563, 851–862. https://doi.org/10.1016/j.jhydrol.2018.06.046 DOI: https://doi.org/10.1016/j.jhydrol.2018.06.046

Song, Z., Shi, W., Zhang, J., Yuan, D., Wu, Q., & Wang, R. (2020). Impact of sea level rise on estuarine salt water intrusion–A numerical model study for Changjiang Estuarine. IOP Conference Series: Earth and Environmental Science, 525, 012130. https://doi.org/10.1088/1755-1315/525/1/012130 DOI: https://doi.org/10.1088/1755-1315/525/1/012130

Sriapai, T., Walsri, C., Phueakphum, D., & Fuenkajorn, K. (2012). Physical model simulations of seawater intrusion in unconfined aquifer. Songklanakarin Journal of Science & Technology, 34(6).

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

Verruijt, A. (1968). A note on the Ghyben-Herzberg formula. Hydrological Sciences Journal, 13(4), 43–46. DOI: https://doi.org/10.1080/02626666809493624

Voss, A., & Koch, M. (2001). Numerical simulations of topography-induced saltwater upconing in the state of Brandenburg, Germany. Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere, 26(4), 353–359. https://doi.org/10.1016/S1464-1909(01)00018-1 DOI: https://doi.org/10.1016/S1464-1909(01)00018-1

Voss, C. I., & 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 DOI: https://doi.org/10.1029/WR023i010p01851

Vu, D. T., Yamada, T., & Ishidaira, H. (2018). Assessing the impact of sea level rise due to climate change on seawater intrusion in Mekong Delta, Vietnam. Water Science and Technology, 77(6), 1632–1639. https://doi.org/10.2166/wst.2018.038 DOI: https://doi.org/10.2166/wst.2018.038

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 DOI: 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. Advances in Water Resources, 51, 3–26. https://doi.org/10.1016/j.advwatres.2012.03.004 DOI: https://doi.org/10.1016/j.advwatres.2012.03.004

Sobhy R. Emara, Irrigation and Hydraulics Engineering Department, Faculty of Engineering, Tanta University, Tanta

 

 

Emara, S. R., Armanuos, A. M., Gado, T. A., & Zeidan, B. A. (2023). Verification of experimental saltwater intrusion interface in unconfined coastal aquifers using numerical and analytical solutions. Acque Sotterranee - Italian Journal of Groundwater, 12(3), 23–38. https://doi.org/10.7343/as-2023-668

Downloads

Download data is not yet available.

Citations