@article{fdi:010046970,
  title = {{C}haracterization of crystalline basement aquifers with {MRS} : comparison with boreholes and pumping tests data in {B}urkina {F}aso},
  author = {{V}ouillamoz, {J}ean-{M}ichel and {D}escloitres, {M}arc and {T}oe, {G}. and {L}egchenko, {A}natoli},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n the {S}ahelian region of {B}urkina {F}aso ({W}estern {A}frica), groundwater resources are scarce. {T}he hydrogeological context is mainly crystalline basement aquifers that often present a challenge to hydrogeologists when investigating their exploration and management. {A} magnetic resonance sounding ({MRS}) survey was conducted to evaluate the ability of the method to answer the following main questions encountered by hydrogeologists in this hard-rock context: center dot {W}here is the groundwater? center dot {H}ow deep and how thick are the water-bearing formations? center dot {W}hat are the reserves of groundwater? center dot {W}hat is the productivity of the aquifer? {MRS} measurements were implemented around recent boreholes drilled both in the weathered and in the fissured-fractured units of the reservoirs. {I}n order to evaluate the {MRS} method, {MRS} results are compared with borehole and pumping test data. {T}he depths and thicknesses of the saturated aquifers encountered by the boreholes are compared with those estimated by {MRS}. {T}he {T}, decay-time constant of the magnetic resonance signal is used for calculating the storativity and transmissivity estimators from geophysical data. {T}hese {MRS} hydrogeological estimators are compared with the local transmissivity and storativity of the aquifer, estimated from pumping test results. {T}he main conclusions of the comparison between the 13 {MRS} results and the borehole data are: center dot {T}he depths and thicknesses of the saturated alterites are accurately described by the {MRS} results, and the mean differences with the borehole data are +/- 12% and +/- 17%, respectively. center dot {T}he storativity estimated from {MRS} data is not reliable. {T}he proposed estimators need to be confirmed with larger data sets, and further research needs to be conducted on this matter. center dot {T}he transmissivity can be accurately estimated from {MRS} data after calibration with pumping test results. {T}he mean difference between {MRS} and pumping test results is +/- 41%. center dot {T}he main limiting factors of {MRS} applied in hard-rock areas are the {I} {D} approximation in a highly heterogeneous context, the screen effect that causes deep weathered-fissured reservoirs to be poorly resolved when topped by shallow alterites reservoirs, and the suppression principle that causes deep narrow fractures to be undetectable. {MRS} is a useful tool to characterize the saturated alterites and the weathered-fissured zones of aquifers in a crystalline rock context. {W}ith knowledge of its limitations, its use within the framework of hydrogeological strategy is promising, both for borehole implementation and for groundwater reserve evaluation.},
  keywords = {},
  booktitle = {},
  journal = {{N}ear {S}urface {G}eophysics},
  volume = {3},
  numero = {3},
  pages = {205--213},
  ISSN = {1569-4445},
  year = {2005},
  URL = {https://www.documentation.ird.fr/hor/fdi:010046970},
}