@article{fdi:010055913,
  title = {{H}ydrological deformation induced by the {W}est {A}frican {M}onsoon : comparison of {GPS}, {GRACE} and loading models},
  author = {{N}ahmani, {S}. and {B}ock, {O}. and {B}ouin, {M}. {N}. and {S}antamaria-{G}omez, {A}. and {B}oy, {J}. {P}. and {C}ollilieux, {X}. and {M}etivier, {L}. and {P}anet, {I}. and {G}enthon, {P}ierre and de {L}inage, {C}. and {W}oppelmann, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}hree-dimensional ground deformation measured with permanent {GPS} stations in {W}est {A}frica was used for investigating the hydrological loading deformation associated with {M}onsoon precipitation. {T}he {GPS} data were processed within a global network for the 2003-2008 period. {W}eekly station positions were retrieved with a repeatability (including unmodeled loading effects) of 1-2 mm in the horizontal components and between 2.5 and 6 mm in the vertical component. {T}he annual signal in the vertical component for sites located between 9.6 degrees {N} and 16.7 degrees {N} is in the range 10-15 mm. {I}t is consistent at the 3 mm-level with the annual regional-scale loading deformations estimated from {GRACE} satellite products and modeled with a combination of hydrological, atmospheric, and nontidal oceanic models. {A}n additional 6 month transient signal was detected in the vertical component of {GPS} estimates at most of the {W}est {A}frican sites. {I}t takes the form of an oscillation occurring between {S}eptember and {M}arch, and reaching a maximum amplitude of 12-16 mm at {O}uagadougou (12.5 degrees {N}). {T}he analysis of in situ hydro-geological data revealed a strong coincidence between this transient signal and peak river discharge at three sites located along the {N}iger {R}iver ({T}imbuktu, {G}ao, and {N}iamey). {A}t {O}uagadougou, a similar coincidence was found with the seasonal variations of the water table depth. {W}e propose a mechanism to account for this signal that involves a sequence of swelling/shrinking of clays combined with local loading effects associated with flooding of the {N}iger {R}iver.},
  keywords = {},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch : {S}olid {E}arth},
  volume = {117},
  numero = {},
  pages = {{B}05409},
  ISSN = {0148-0227},
  year = {2012},
  DOI = {10.1029/2011jb009102},
  URL = {https://www.documentation.ird.fr/hor/fdi:010055913},
}