Gallay M. auteur aut IRD Martinez Jean-Michel auteur aut IRD Allo S. auteur aut IRD Mora A. auteur aut IRD Cochonneau Gérard auteur aut IRD Gardel A. auteur aut IRD Doudou Jean-Claude auteur aut IRD Sarrazin Max auteur aut IRD Chow-Toun F. auteur aut IRD Laraque Alain auteur aut IRD text journalArticle eng text/pdf born digital access We analyzed two contrasting catchments located among the world's largest unspoiled tropical rainforests impacted by mining in the northeastern coastlands of South America. We used the following: (a) mining, agricultural, and urbanized areas to compare the land use evolution with suspended sediments and sediment yields; (b) field monthly river suspended sediments in the two catchments (2004-2015: n = 154); (c) MODIS remote sensing water color technique in the Maroni basin to complete (n = 387) and extend field suspended sediment sampling from 2000 to 2015; (d) hydroclimatic statistical analysis conditions and sediment concentrations to identify the long-term trends, the abrupt changes in time series and to analyze if the environmental and anthropogenic factors control sediment yield regional variations. No significant long-term changes were observed in precipitation or water discharge with the Mann-Kendall test. However, the mean suspended sediment concentration has increased significantly (239%) in the Maroni River with a breakpoint in 2009 and decreased (33%) in the Oyapock River (breakpoint in 2008). These differences are explained by the larger percentage of deforestation because of mining activities in the Maroni (0.37%) than in the Oyapock (0.06%) catchment. In the Maroni River, the increasing sediment yield trend (2000-2015) coincide significantly (r2 = 0.97; p < 0.0001) with the increase of 400% of mining areas, whereas no significant relationship with the runoff was found. In the Oyapock River, the runoff explains the sediment yield decreasing trend (r2 = 0.82; p < 0.0001) and no relationship with the land use change was found. specialized land degradation mining MODIS runoff sediment yields GUYANE FRANCAISE MARONI COURS D'EAU OYAPOCK COURS D'EAU 038 064 062 126 021 29 12 4323-4336 2018 1085-3278 https://www.documentation.ird.fr/hor/fdi:010075627 10.1002/ldr.3150 1085-3278 [F B010075627] https://www.documentation.ird.fr/hor/fdi:010075627 https://www.documentation.ird.fr/intranet/publi/2019/05/010075627.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2019-06-04 2023-07-11 fdi:010075627 fre