Fluvial sediment dynamics plays a key role in the Amazonian environment, with most of the sediments originating in the Andes. The Madeira River, the second largest tributary of the Amazon River, contributes up to 50% of its sediment discharge to the Atlantic Ocean, most of it provided by the Andean part of the Madeira basin, in particular the Beni River. In this study, we assessed the rainfall (R)-surface suspended sediment concentration (SSSC) and discharge (Q)-SSSC relationship at the Rurrenabaque station (200 m a.s.l.) in the Beni Andean piedmont (Bolivia). We started by showing how the R and Q relationship varies throughout the hydrological year (September to August), describing a counter-clockwise hysteresis, and went on to evaluate the R–SSSC and Q–SSSC relationships. Although no marked hysteresis is observed in the first case, a clockwise hysteresis is described in the second....

The Madeira River is the second largest Amazon tributary, contributing up to 50% of the Amazon River’s sediment load. The Madeira has significant hydropower potential, which has started to be used by the Madeira Hydroelectric Complex (MHC), with two large dams along the middle stretch of the river. In this study, fine suspended sediment concentration (FSC) data were assessed downstream of the MHC at the Porto Velho gauging station and at the outlet of each tributary (Beni and Mamoré Rivers, upstream from the MHC), from 2003 to 2017. When comparing the pre-MHC (2003–2008) and post-MHC (2015–2017) periods, a 36% decrease in FSC was observed in the Beni River during the peak months of sediment load (December–March). At Porto Velho, a reduction of 30% was found, which responds to the Upper Madeira Basin and hydroelectric regulation. Concerning water discharge, no significant change ...

El estudio de Molina-Carpio et al. (2023) tuvo como objetivo identificar regiones de lluvia homogéneas dentro de la cuenca alta del río Madeira (Bolivia, Perú y Brasil), que abarca 975.000 km2 y tiene un rango de elevación de 50 a 6450 m s. n. m. Para ello, se usaron series mensuales de 146 estaciones terrestres de los 3 países. Sin imponer restricciones espaciales, el análisis de Agrupamiento Jerárquico (AJ) y el Análisis de Componentes Principales (ACP) agruparon de manera óptima 146 estaciones (1980-2016) en 10 regiones homogéneas distribuidas a lo largo de los Andes y la llanura amazónica. Luego, al aplicar el ACP a las series de lluvias estacionales y vincular los componentes principales con la temperatura de la superficie del mar e índices oceánicos, se obtuvo una perspectiva de los principales moduladores a gran escala de la variabilidad espacio-temporal de las lluvia...