Gallay M. auteur aut IRD Martinez Jean-Michel auteur aut IRD Mora A. auteur aut IRD Castellano B. auteur aut IRD Yepez S. auteur aut IRD Cochonneau Gérard auteur aut IRD Alfonso J. A. auteur aut IRD Carrera J. M. auteur aut IRD Lopez J. L. auteur aut IRD Laraque Alain auteur aut IRD text journalArticle eng text/pdf born digital access The aim of this study was to derive the Surface Suspended Sediment Concentration (SSSC) and river sediment discharge (for the period 2000-2016) along the Orinoco River reaches using MODIS remote sensing data. A single SSC retrieval algorithm was calibrated using HYBAM long term monitoring program data (n = 183). The comparison of satellite and field measurements showed a RMSE of 32%, corresponding to a mean absolute error of 21 mg l(-1). These results supported the use of MODIS sensors to monitor the SSSC at six virtual stations in the middle and lower reaches of the Orinoco River. The highest mean SSSC were found downstream of the Meta River (101 mg l(-1)) and of the Apure River (99 mg l(-1)), which provide the major sediment input to the Orinoco main stream. The lowest mean SSSC was found upstream of the Meta River (42 mg l(-1)). In the lower reach, at Ciudad Bolivar station we assessed a mean SSSC of 88 mg l(-1). MODIS-derived and ground-derived assessments of the annual sediment discharge show very fine agreement, within -2%. Coupling satellite-derived SSSC estimates and river discharge monitoring data, we calculated the Orinoco River sediment discharge at Ciudad Bolivar station between 2001 and 2016. For a mean Orinoco River discharge of 33,320 m3.s(-1), the sediment loads varied from 75 to 103 Mt.yr(-1), with a mean value of 89 Mt.yr-1 (RSD of 9%) corresponding to a sediment yield of 91-125 t.km(-2)yr-1 with no positive or negative trends over the observed period. specialized MODIS Suspended sediments Sediment load Orinoco river Water color VENEZUELA COLOMBIE ORENOQUE COURS D'EAU 062 126 91 320-331 2019 0895-9811 https://www.documentation.ird.fr/hor/fdi:010075749 10.1016/j.jsames.2019.01.010 0895-9811 [F B010075749] https://www.documentation.ird.fr/hor/fdi:010075749 https://www.documentation.ird.fr/intranet/publi/2019/06/010075749.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2019-07-05 2025-02-24 fdi:010075749 fre