1887
Geoelectrical Monitoring
  • ISSN: 1569-4445
  • E-ISSN: 1873-0604
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Abstract

ABSTRACT

A major problem for the freshwater supply of coastal regions is the intrusion of saltwater into aquifers. Due to extensive extraction of freshwater to suffice increasing drinking water demands and/or in periods of reduced groundwater recharge, the equilibrium state may be disturbed. The result is an upconing or movement of the fresh–saline groundwater interface, which reduces the local drinking water resources at coastal regions or islands. The saltwater monitoring system (SAMOS) is a vertical electrode chain installed in a backfilled borehole. It provides a solution to observe the transition zone in detail, both temporally and spatially. We present monitoring data of the first year from three locations ‐ with different geological conditions that show disturbances in the resistivity distribution that result from the drilling processes. A clayey backfilling, for example, can lead to beam‐like artefacts, and a mixed fluid within the backfilling changes its bulk resistivity, both leading to misinterpretations. We performed data inversion under cylindrically symmetrical conditions in full‐space in order to separate these resistivity artefacts from the undisturbed background. Data inversion reveals that it is possible to separate drilling effects on the resistivity distribution from the undisturbed background. Thus, an interpretation of the natural transition zones can be made immediately after the installation.

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2020-07-28
2024-03-29
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References

  1. Baisset, M. and Neyens, D. (2018) High frequency saltwater intrusion monitoring using borehole geophysical tools (SMD). In: 25th Salt Water Intrusion Meeting, 17–22 June 2018, Gdansk, Poland.
    [Google Scholar]
  2. Binley, A., Winship, P., West, L., Pokar, M. and Middleton, R. (2002) Seasonal variation of moisture content in unsaturated sandstone inferred from borehole radar and resistivity profiles. Journal of Hydrology, 267, 160–172.
    [Google Scholar]
  3. Cheng, A.‐D., Halhal, D., Naji, A. and Ouazar, D. (2000) Pumping optimization in saltwater‐intruded coastal aquifers. Water Resources Research, 36, 2155–2165.
    [Google Scholar]
  4. Cooper, H. (1959) A hypothesis concerning the dynamic balance of fresh water and salt water in a coastal aquifer. Journal of Geophysical Research, 64, 461–467.
    [Google Scholar]
  5. Coscia, I., Greenhalgh, S., Linde, N., Doetsch, J., Marescot, L., Günther, T. and Green, A. (2011) 3D crosshole apparent resistivity static inversion and monitoring of a coupled river‐aquifer system. Geophysics, 76, G49–59.
    [Google Scholar]
  6. Doetsch, J., Coscia, I., Greenhalgh, S., Linde, N., Green, A. and Günther, T. (2010) The borehole‐fluid effect in electrical resistivity imaging. Geophysics, 75(4), F107–F114.
    [Google Scholar]
  7. Ferguson, G. and Gleeson, T. (2012) Vulnerability of coastal aquifers to groundwater use and climate change. Nature Climate Change, 2, 342–345.
    [Google Scholar]
  8. Grinat, M., Südekum, W., Epping, D., Grelle, T. and Meyer, R. (2010) An automated electrical resistivity tomography system to monitor the freshwater/saltwater zone on a north sea island. In: Near Surface 2010–16th EAGE European Meeting of Environmental and Engineering Geophysics. EAGE Publications. https://doi.org/10.3997/2214-4609.20144785.
    [Google Scholar]
  9. Günther, T. and Müller‐Petke, M. (2012) Hydraulic properties at the North Sea island of Borkum derived from joint inversion of magnetic resonance and electrical resistivity soundings. Hydrology and Earth System Sciences, 16(9), 3279–3291.
    [Google Scholar]
  10. Igel, J., Günther, T. and Kuntzer, M. (2013) Ground‐penetrating radar insight into a coastal aquifer: the freshwater lens of Borkum Island. Hydrology and Earth System Sciences, 17, 519–531.
    [Google Scholar]
  11. Kemna, A., Vanderborght, J., Kulessa, B. and Vereecken, H. (2002) Imaging and characterisation of subsurface solute transport using electrical resistivity tomography (ERT) and equivalent transport models. Journal of Hydrology, 267, 125–146.
    [Google Scholar]
  12. Kuras, O., Pritchard, J., Meldrum, P.I., Chambers, J.E., Wilkinson, P.B., Ogilvy, R.D. and Wealthall, G.P. (2009) Monitoring hydraulic processes with automated time‐lapse electrical resistivity tomography (ALERT). Compte Rendus Geosciences – Special Issue on Hydrogeophysics, 341, 868–885.
    [Google Scholar]
  13. Loke, M.H., Chambers, J.E., Rucker, D.F., Kuras, O. and Wilkinson, P.B. (2013) Recent developments in the direct‐current geoelectrical imaging method. Journal of Applied Geophysics, 95, 135–156.
    [Google Scholar]
  14. Ogilvy, R.D., Meldrum, P.I., Kuras, O., Wilkinson, P.B., Chambers, J.E., Sen, M., Pulido‐Bosch, A., Gisbert, J., Jorreto, S., Frances, I. and Tsourlos, P. (2009) Automated monitoring of coastal aquifers with electrical resistivity tomography. Near Surface Geophysics, 7, 367–375.
    [Google Scholar]
  15. Rasmussen, P., Sonnenborg, T.O., Goncear, G. and Hinsby, K. (2013) Assessing impacts of climate change, sea level rise, and drainage canals on saltwater intrusion to coastal aquifer. Hydrology and Earth System Sciences, 17, 421–443.
    [Google Scholar]
  16. Ronczka, M., Günther, T. and Grinat, M. (2020) SAMOS monitoring data for CLIWAT1, CLIWAT2 and goCAM1. https://doi.org/10.5281/zenodo.3609110.
  17. Ronczka, M., Rücker, C. and Günther, T. (2015) Numerical study of long‐electrode electric resistivity tomography — Accuracy, sensitivity, and resolution. Geophysics, 80, E317–E328.
    [Google Scholar]
  18. Rücker, C. and Günther, T. (2011) The simulation of finite ert electrodes using the complete electrode model. Geophysics, 76, F227–F238.
    [Google Scholar]
  19. Rücker, C., Günther, T. and Wagner, F.M. (2017) pyGIMLi: An open‐source library for modelling and inversion in geophysics. Computers and Geosciences, 109, 106–123.
    [Google Scholar]
  20. Rucker, D.F., Loke, M.H., Levitt, M.T. and Noonan, G.E. (2010) Electrical‐resistivity characterization of an industrial site using long electrodes. Geophysics, 75, WA95–WA104.
    [Google Scholar]
  21. Schneider, J.C. and Kruse, S.E. (2006) Assessing selected natural and anthropogenic impacts on freshwater lens morphology on small barrier islands: Dog Island and St. George Island, Florida, USA. Hydrogeology Journal, 14, 131–145.
    [Google Scholar]
  22. Schöniger, H., Eley, M., Langman, T., Schimmelpfenning, S., Kejo, H., Sander, M., Wiederhold, H., Ronczka, M., Schneider, A., Zhao, H. and Koch, A. (2019) Salt water meets fresh water ‐ scientific approach meets social needs. In: Proceedings of the 38th IAHR World Congress, Panama City, Panama.
    [Google Scholar]
  23. Sherif, M., Kacimov, A., Javadi, A. and Ebraheem, A.A. (2012) Modeling groundwater flow and seawater intrusion in the coastal aquifer of Wadi Ham, UAE. Water Resources Management, 26, 751–774.
    [Google Scholar]
  24. Si, H. (2015) Tetgen, a delaunay‐based tetrahedral mesh generator. ACM Transactions on Mathematical Software, 41, 1–36.
    [Google Scholar]
  25. Siemon, B., Costabel, S., Voß, W., Meyer, U., Deus, N., Elbracht, J., Günther, T. and Wiederhold, H. (2015) Airborne and ground geophysical mapping of coastal clays in Eastern Friesland, Germany. Geophysics, 80, WB21–WB34.
    [Google Scholar]
  26. Siemon, B., Steuer, A. and Meyer, U. (2018) Review of BGR's HEM surveys in Germany. In: Proceedings of 7th International Workshop on Airborne Electromagnetics, Kolding, DK.
    [Google Scholar]
  27. Sulzbacher, H., Wiederhold, H., Siemon, B., Grinat, M., Igel, J., Burschil, T., Günther, T. and Hinsby, K. (2012) Numerical modelling of climate change impacts on freshwater lenses on the North Sea island of Borkum using hydrological and geophysical methods. Hydrology and Earth System Sciences, 16, 3621–3643.
    [Google Scholar]
  28. Tsourlos, P., Ogilvy, R., Meldrum, P. and Williams, G. (2003) Time‐lapse monitoring in single boreholes using electrical resistivity tomography. Journal of Environmental and Engineering Geophysics, 8, 1–14.
    [Google Scholar]
  29. Tsourlos, P., Vargemezis, G., Voudouris, C., Spachos, T. and Stampolidis, A. (2007) Monitoring recycled water injection into a confined aquifer in Sindos (Thessaloniki) using electrical resistivity tomography (ERT): installation and preliminary results. Bulletin of the Geological Society of Greece, 40, 580.
    [Google Scholar]
  30. Watlet, A., Kaufmann, O., Triantafyllou, A., Poulain, A., Chambers, J.E., Meldrum, P.I., Wilkinson, P.B., Hallet, V., Quinif, Y., Van Ruymbeke, M., and Van Camp, M. (2018) Imaging groundwater infiltration dynamics in the karst vadose zone with long‐term ERT monitoring. Hydrology and Earth System Sciences, 22, 1563–1592.
    [Google Scholar]
  31. Whiteley, J.S., Chambers, J.E., Uhlemann, S., Wilkinson, P.B. and Kendall, J.M. (2019) Geophysical monitoring of moisture‐induced landslides. A Review: Reviews of Geophysics, 57, 106–145.
    [Google Scholar]
  32. Wiederhold, H., Sulzbacher, H., Grinat, M., Günther, T., Igel, J., Burschil, T. and Siemon, B. (2013) Hydrogeophysical characterization of freshwater/saltwater systems – case study, Borkum Island, Germany. First Break, 31, 109–117.
    [Google Scholar]
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  • Article Type: Research Article
Keyword(s): Electrical resistivity tomography; Groundwater; Hydrogeophysics

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