Sediment flows in South America supported by daily
hydrologic-hydrodynamic modeling
Abstract
Suspended sediments (SS) 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, datasets 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.