@article{fdi:010077391,
  title = {{G}eochemistry of the {L}ake {C}had tributaries under strongly varying hydro-climatic conditions},
  author = {{N}our, {A}. {M}. and {V}allet-{C}oulomb, {C}. and {B}ouchez, {C}. and {G}inot, {P}atrick and {D}oumnang, {J}. {C}. and {S}ylvestre, {F}lorence and {D}eschamps, {P}ierre},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {L}ake {C}had {B}asin ({LCB}) is one of the main endorheic basins in the world and has undergone large-level and surface variations during the last decades, particularly during the {S}ahelian dry period in the 1970s and the 1980s. {T}he {C}hari-{L}ogone {R}iver system covers 25% of the {LCB} but accounts for up to 82% of the {L}ake {C}had water supply. {T}he aim of this study is to investigate the dissolved phase transported by the {C}hari-{L}ogone system, in order (1) to elucidate the origin and the behavior of major elements and the weathering processes in the watershed; (2) to estimate the total dissolved flux, its variability over the last decades and the driving factors. {T}o do so, samples were collected monthly between {J}anuary 2013 and {N}ovember 2016 at three representative sites of the basin: in the {C}hari {R}iver in "{C}hagoua," in the {L}ogone {R}iver in "{N}gueli" just before the confluence of both rivers, and at a downstream site in "{D}ouguia," 30 km after the confluence. {C}oncentrations in major elements displayed significant seasonal variations in the {C}hari and {L}ogone waters. {A}t the seasonal time scale, the comparison between the concentrations of chemical elements and the flow rates showed a hysteresis loop. {T}his hysteresis behavior corresponds to a variable contribution over time of two water bodies, fast surface water, and slow groundwater, the latter carrying higher concentrations and {C}a/{N}a ratio, which may result from the contribution of pedogenic carbonate weathering to the dominant signature of silicate weathering. {A}t the annual time scale, similar average concentrations are observed in the {C}hari and {L}ogone {R}ivers, despite contrasted annual runoff. {I}n addition, an interannual stability of ionic concentrations was observed in the {C}hari-{L}ogone {R}iver during the flood regime, both during the years covered by our monitoring (2013-2016) and during the pre-drought period (1969, 1972 and 1973). {T}his situation corresponds to a chemostatic behavior, where the annual river discharge is the main factor controlling the interannual variation of chemical fluxes.},
  keywords = {{L}ake {C}had {B}asin ; {C}hemical fluxes ; {S}ilicate weathering ; {S}trontium ; {TCHAD} {LAC}},
  booktitle = {},
  journal = {{A}quatic {G}eochemistry},
  volume = {26},
  numero = {1},
  pages = {3--29},
  ISSN = {1380-6165},
  year = {2019},
  DOI = {10.1007/s10498-019-09363-w},
  URL = {https://www.documentation.ird.fr/hor/fdi:010077391},
}