@article{fdi:010062492,
  title = {{T}emporal variation and fluxes of dissolved and particulate organic carbon in the {A}pure, {C}aura and {O}rinoco rivers, {V}enezuela},
  author = {{M}ora, {A}. and {L}araque, {A}lain and {M}oreira {T}urcq, {P}atricia and {A}lfonso, {J}. {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he concentrations of total suspended sediments ({TSS}), dissolved organic carbon ({DOC}) and particulate organic carbon ({POC}) were measured in water samples taken monthly in the {A}pure, {C}aura and {O}rinoco rivers during a hydrological cycle (between {S}ept. 2007 and {A}ug. 2008). {T}he {DOC} concentration values ranged between 1.5 and 6.8 mg{C} l(-1) in the {A}pure {R}iver; 2.07 and 4.9 mg{C} l(-1) in the {C}aura {R}iver and 1.66 and 5.35 mg{C} l(-1) in the {O}rinoco {R}iver. {T}he mean concentration of {DOC} was 3.9 mg{C} l-1 in the {A}pure {R}iver, 3.24 mg{C} l(-1) in the {C}aura {R}iver and 2.92 mg{C} l(-1) in the {O}rinoco {R}iver at {P}uerto {O}rdaz. {T}he three rivers showed a similar temporal pattern in the concentrations of {DOC}, with higher {DOC} values during the increasing branch of the hydrograph due to wash-out processes of the organic material stored in soils. {T}he mean concentration values of {POC} were 1.33 mg{C} l(-1); 0.77 mg{C} l(-1) and 0.91 mg{C} l(-1) in the {A}pure, {C}aura and {O}rinoco rivers, respectively. {T}he inverse relationship found between the percentage in weight of the {POC} and the concentrations of {TSS} in the three rivers fits a logarithmic model, as it has been previously reported for other worldwide rivers. {T}he {POC} concentrations in the {O}rinoco {R}iver showed a positive relationship with the {TSS}, suggesting that the {POC} in the {O}rinoco is the result of terrestrially organic matter. {A}lthough the fluxes of organic carbon ({OC}) in the three studied rivers are dependent on the values of water discharge, the fluxes of {DOC} during the increasing branch of the hydrograph are higher than those found during the decreasing stage, due to the yield of organic material accumulated in soils during the preceding dry season. {T}he mean annual flux of total organic carbon ({TOC}) of the {O}rinoco {R}iver at {P}uerto {O}rdaz was about 4.27 x 10(6) {T}on{C} yr(-1). {O}f this, 3.28 x 10(6) {T}on{C} yr(-1) (77%) represents the flux of {DOC} and about 0.99 {T}on{C} yr(-1) (23%) represents the flux of {POC}. {T}he mean annual input of {TOC} from the {A}pure {R}iver to the {O}rinoco {R}iver was about 4.92 x 10(5) {T}on{C} yr(-1) (11.5%), while the contribution of {TOC} from the {C}aura {R}iver to the {O}rinoco {R}iver was estimated at 3.05 x 10(5) {T}on{C} yr(-1) (7.1%). {T}he values of annual transport of {TOC} calculated for the {A}pure, {C}aura and {O}rinoco rivers were lower than those reported twenty years ago. {T}his could be related to interannual variations of precipitation in the {O}rinoco {B}asin, due to runoff variations can have a strong effect on the fluxes of {OC} from land to rivers.},
  keywords = {{DOC} ; {TOC} ; {OC} fluxes ; {O}rinoco {R}iver ; {A}pure {R}iver ; {C}aura {R}iver ; {VENEZUELA}},
  booktitle = {},
  journal = {{J}ournal of {S}outh {A}merican {E}arth {S}ciences},
  volume = {54},
  numero = {},
  pages = {47--56},
  ISSN = {0895-9811},
  year = {2014},
  DOI = {10.1016/j.jsames.2014.04.010},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062492},
}