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@ARTICLE{Nguyen:6379,
      author       = {Nguyen, F. and Kemna, A. and Antonsson, A. and Engesgaard,
                      P. and Kuras, O. and Ogilvy, R. and Gisbert, J. and Jorreto,
                      S. and Pulido-Bosch, A.},
      title        = {{C}haracterization of seawater intrusion using 2{D}
                      electrical imaging},
      journal      = {Near surface geophysics},
      volume       = {7},
      issn         = {1569-4445},
      address      = {Houten},
      publisher    = {EAGE},
      reportid     = {PreJuSER-6379},
      year         = {2009},
      note         = {We would like to thank the associate editor Lee Slater and
                      the two reviewers Kamini Singha and Mark Goldman for their
                      pertinent comments and suggestions, which have greatly
                      improved this manuscript. We also thank Frederic Day-Lewis
                      for fruitful email exchanges. We would like also to thank
                      all the people who contributed to this work on the field, in
                      Almeria and in the laboratory of the Forschungszentrum
                      Juelich. This work is part of the EU project ALERT
                      (GOCE-CT-2004-505329). We thank also the Fonds de la
                      Recherche Scientifique - FNRS (Belgium) and the University
                      of Copenhagen for providing logistical support to this
                      research.},
      abstract     = {We have investigated the potential of 2D electrical imaging
                      for the characterization of seawater intrusion using field
                      data from a site in Almeria, SE Spain. Numerical simulations
                      have been run for several scenarios, with a hydrogeological
                      model reflecting the local site conditions. The simulations
                      showed that only the lower salt concentrations of the
                      seawater-freshwater transition zone could be recovered, due
                      to the loss of resolution with depth. We quantified this
                      capability in terms of the cumulative sensitivity associated
                      with the measurement setup and showed that the mismatch
                      between the targeted and imaged parameter values occurs from
                      a certain sensitivity threshold. Similarly, heterogeneity
                      may only be determined accurately if located in an
                      adequately sensitive area. At the field site, we identified
                      seawater intrusion at the scale of a few kilometres down to
                      a hundred metres. Borehole logs show a remarkable
                      correlation with the image obtained from surface data but
                      indicate that the electrically derived mass fraction of pure
                      seawater could not be recovered due to the discrepancy
                      between the in-situ and laboratory-derived petrophysical
                      relationships. Surface-to-hole inversion results suggest
                      that the laterally varying resolution pattern associated
                      with such a setup dominates the image characteristics
                      compared to the laterally more homogeneous resolution
                      pattern of surface only inversion results and hence,
                      surface-to-hole images are not easily interpretable in terms
                      of larger-scale features. Our results indicate that
                      electrical imaging can be used to constrain seawater
                      intrusion models if image appraisal tools are appropriately
                      used to quantify the spatial variation of sensitivity and
                      resolution. The most crucial limitation is probably the
                      apparent non-stationarity of the petrophysical relationship
                      during the imaging process.},
      keywords     = {J (WoSType)},
      cin          = {ICG-4},
      ddc          = {550},
      cid          = {I:(DE-Juel1)VDB793},
      pnm          = {Terrestrische Umwelt},
      pid          = {G:(DE-Juel1)FUEK407},
      shelfmark    = {Geochemistry $\&$ Geophysics},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000270895200008},
      doi          = {10.3997/1873-0604.2009025},
      url          = {https://juser.fz-juelich.de/record/6379},
}