@article{fdi:010062610,
  title = {{H}ydrograph separation to improve understanding of {D}issolved {O}rganic {C}arbon dynamics in headwater catchments},
  author = {{C}haplot, {V}incent and {R}ibolzi, {O}livier},
  editor = {},
  language = {{ENG}},
  abstract = {{D}issolved organic carbon ({DOC}) is a key component of the global carbon cycle, but, to date, large uncertainties still exist on its source and fate in first-order streams. {I}n a 23 ha rangeland and steep-slope headwater of {S}outh {A}frica, our aim was to quantify the contribution of overland flow ({OF}), soil water ({SW}) and ground water ({GW}) to {DOC} fluxes ({DOCF}), and to interpret the results in terms of {DOC} sources and fate. {T}he average 2010-2011 {DOC} concentration ({DOCC}) at the catchment outlet was 4.7 mg {C} l(-1) with a standard error of +/- 2.5 mg {C} l(-1), which was significantly lower than in {SW} (15.2 +/- 1.6 mg {C} l(-1)) and {OF} (11.9 +/- 0.8 mg {C} l(-1)), but higher than in {GW} (2.3 +/- 0.6 mg {C} l(-1)). {B}ased on end-member mixing using {S}i and {N}a concentration in the water compartments, the average {SW} contribution to {DOCF} was 66.4%, followed by {OF} (30.0%) and {GW} (3.6%). {T}he resulting estimated {DOCF} at the catchment outlet was 8.05 g {C} m(2) y(-1). {T}his was much higher than the observed value of 2.80 g {C} m(2) y(-1), meaning that 5.25 g {C} m(2) y(-1) or 65% of the {DOC} is lost during its downslope and/or downstream transport to the catchment outlet. {C}omplementary investigations revealed that the {DOCC} in {SW} dropped from 15.2 +/- 1.6 to 2.6 +/- 0.3 mg {C} l(-1) during its downslope transport to the river system, which corresponded to a net loss of 5.10 g {C} m(2) y(-1), or 97% of the catchment {DOC} losses. {T}hese results on {DOC} sources and potential fate in headwaters are expected to improve our understanding of the impact of hydrology on the global {C}-cycle.},
  keywords = {nutrient cycles ; global change ; greenhouse gases ; ecosystems ; carbon ; {AFRIQUE} {DU} {SUD}},
  booktitle = {},
  journal = {{H}ydrological {P}rocesses},
  volume = {28},
  numero = {21},
  pages = {5354--5366},
  ISSN = {0885-6087},
  year = {2014},
  DOI = {10.1002/hyp.10010},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062610},
}