Sediment Flows in South America Supported by Daily Hydrologic‐Hydrodynamic Modeling

Suspended sediments (SSs) contribute to the maintenance of several ecosystems. However, intense soil erosion can lead to environmental, social, and economic impacts. South America (SA) has very high erosion and sediment transport rates. Here, we present a detailed description of the spatio‐temporal dynamics of natural SS flows in SA using the continental sediment model MGB‐SED AS. We evaluate the model with daily in situ data from 595 stations, information from regional studies and a global model. The model performance analysis showed that, in general, there was a better agreement between simulated and observed data than with the information found in regional studies and of the global model. The use of the hydrodynamic propagation method has allowed a better representation of sediment flows in rivers and floodplains. Based in the calibrated model results, SA delivers 1.00 × 109 t/year of SS to the oceans, in which the Amazon (4.36 × 108 t/year), Orinoco (1.37 × 108 t/year), La Plata (1.11 × 108 t/year), and Magdalena (3.26 × 107) rivers are the main suppliers. The floodplains play an essential role, retaining about 12% (2.40 × 108 t/year) of the SS loads reaching the rivers. In this study, data sets related to SS flows in SA were generated and can be used to support other large‐scale researches or policymakers and stakeholders for adequate management of continental land use. Key Points First assessment of natural spatio‐temporal sediment dynamics in South America from physically based model Floodplains anticipate the peak of suspended sediment discharge, and retain almost 12% of sediments South America exports 2.76 Mt/day of suspended sediments to the oceans; 44%, 14%, and 11% come from Amazon, Orinoco, and La Plata rivers, respectively