@article{fdi:010075509,
  title = {{R}elationships between rainfall and groundwater recharge in seasonally humid {B}enin : a comparative analysis of long-term hydrographs in sedimentary and crystalline aquifers},
  author = {{K}otchoni, {D}. {O}. {V}. and {V}ouillamoz, {J}ean-{M}ichel and {L}awson, {F}. {M}. {A}. and {A}djomayi, {P}. and {B}oukari, {M}. and {T}aylor, {R}. {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{G}roundwater is a vital source of freshwater throughout the tropics enabling access to safe water for domestic, agricultural and industrial purposes close to the point of demand. {T}he sustainability of groundwater withdrawals is controlled, in part, by groundwater recharge, yet the conversion of rainfall into recharge remains inadequately understood, particularly in the tropics. {T}his study examines a rare set of 19-25-year records of observed groundwater levels and rainfall under humid conditions (mean rainfall is similar to 1,200mmyear(-1)) in three common geological environments of {B}enin and other parts of {W}est {A}frica: {Q}uaternary sands, {M}io-{P}liocene sandstone, and crystalline rocks. {R}echarge is estimated from groundwater-level fluctuations and employs values of specific yield derived from magnetic resonance soundings. {R}echarge is observed to occur seasonally and linearly in response to rainfall exceeding an apparent threshold of between 140 and 250mmyear(-1). {I}nter-annual changes in groundwater storage correlate well to inter-annual rainfall variability. {H}owever, recharge varies substantially depending upon the geological environment: annual recharge to shallow aquifers of {Q}uaternary sands amounts to as much as 40% of annual rainfall, whereas in deeper aquifers of {M}io-{P}liocene sandstone and weathered crystalline rocks, annual fractions of rainfall generating recharge are 13 and 4%, respectively. {D}ifferences are primarily attributed to the thickness of the unsaturated zone and to the lithological controls on the transmission and storage of rain-fed recharge.},
  keywords = {{G}roundwater recharge ; water budget ; {B}enin ; {S}ub-{S}aharan {A}frica ; {H}ydrograph ; {BENIN} ; {AFRIQUE} {SUBSAHARIENNE}},
  booktitle = {},
  journal = {{H}ydrogeology {J}ournal},
  volume = {27},
  numero = {2},
  pages = {447--457},
  ISSN = {1431-2174},
  year = {2019},
  DOI = {10.1007/s10040-018-1806-2},
  URL = {https://www.documentation.ird.fr/hor/fdi:010075509},
}