@article{fdi:010072360,
  title = {{W}hy 1{D} electrical resistivity techniques can result in inaccurate siting of boreholes in hard rock aquifers and why electrical resistivity tomography must be preferred : the example of {B}enin, {W}est {A}frica},
  author = {{A}lle, {I}. {C}. and {D}escloitres, {M}arc and {V}ouillamoz, {J}ean-{M}ichel and {Y}alo, {N}. and {L}awson, {F}. {M}. {A}. and {A}dihou, {A}. {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{H}ard rock aquifers are of particular importance for supplying people with drinking water in {A}frica and in the world. {A}lthough the common use of one-dimensional (1{D}) electrical resistivity techniques to locate drilling site, the failure rate of boreholes is usually high. {F}or instance, about 40% of boreholes drilled in hard rock aquifers in {B}enin are unsuccessful. {T}his study investigates why the current use of 1{D} techniques (e.g. electrical profiling and electrical sounding) can result in inaccurate siting of boreholes, and checks the interest and the limitations of the use of two-dimensional (2{D}) {E}lectrical {R}esistivity {T}omography ({ERT}). {G}eophysical numerical modeling and comprehensive 1{D} and 2{D} resistivity surveys were carried out in hard rock aquifers in {B}enin. {T}he experiments carried out at 7 sites located in different hard rock groups confirmed the results of the numerical modeling: the current use of 1{D} techniques can frequently leads to inaccurate siting, and {ERT} better reveals hydrogeological targets such as thick weathered zone (e.g. stratiform fractured layer and preferential weathering associated with subvertical fractured zone). {M}oreover, a cost analysis demonstrates that the use of {ERT} can save money at the scale of a drilling programme if {ERT} improves the success rate by only 5% as compared to the success rate obtained with 1{D} techniques. {F}inally, this study demonstrates, using the example of {B}enin, that the use of electrical resistivity profiling and sounding for siting boreholes in weathered hard rocks of western {A}frica should be discarded and replaced by the use of {ERT} technique, more efficient.},
  keywords = {{H}ard rock aquifers ; {B}orehole siting ; 1{D} electrical resistivity techniques ; 2{D} electrical resistivity tomography ; {B}enin ; {W}est {A}frica ; {BENIN}},
  booktitle = {},
  journal = {{J}ournal of {A}frican {E}arth {S}ciences},
  volume = {139},
  numero = {},
  pages = {341--353},
  ISSN = {1464-343{X}},
  year = {2018},
  DOI = {10.1016/j.jafrearsci.2017.12.007},
  URL = {https://www.documentation.ird.fr/hor/fdi:010072360},
}