@article{fdi:010066141,
  title = {{W}ater storage changes as a marker for base flow generation processes in a tropical humid basement catchment ({B}enin) : {I}nsights from hybrid gravimetry},
  author = {{H}ector, {B}. and {S}{\'e}guis, {L}uc and {H}inderer, {J}. and {C}ohard, {J}. {M}. and {W}ubda, {M}. and {D}escloitres, {M}arc and {B}enarrosh, {N}athalie and {B}oy, {J}. {P}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n basement catchments of subhumid {W}est {A}frica, base flow is the main component of annual streamflow. {H}owever, the important heterogeneity of lithology hinders the understanding of base flow generation processes. {S}ince these processes are linked with water storage changes ({WSC}s) across the catchment, we propose the use of hybrid gravity data in addition to neutron probe-derived water content and water levels to monitor spatiotemporal {WSC} of a typical crystalline basement headwater catchment (16 ha) in {B}enin. {WSC} behaviors are shown to provide insights into hydrological processes in terms of water redistribution toward the catchment outlet. {H}ybrid gravimetry produces gravity change observations from time-lapse microgravity surveys coupled with gravity changes monitored at a base station using a superconducting gravimeter and/or an absolute gravimeter. {A} dense microgravity campaign (70 surveys of 14 stations) covering three contrasted years was set up with a rigorous protocol, leading to low uncertainties (< 2.5 mu {G}al) on station gravity determinations (with respect to the network reference station). {E}mpirical orthogonal function analyses of both gravity changes and {WSC}s from neutron probe data show similar spatial patterns in the seasonal signal. {A}reas where storage and water table show a capping behavior (when data reach a plateau during the wet season), suggesting threshold-governed fast subsurface redistribution, are identified. {T}his observed storage dynamics, together with geological structures investigated by electrical resistivity tomography and drill log analysis, make it possible to derive a conceptual model for the catchment hydrology.},
  keywords = {{BENIN}},
  booktitle = {},
  journal = {{W}ater {R}esources {R}esearch},
  volume = {51},
  numero = {10},
  pages = {8331--8361},
  ISSN = {0043-1397},
  year = {2015},
  DOI = {10.1002/2014wr015773},
  URL = {https://www.documentation.ird.fr/hor/fdi:010066141},
}