Resumo

RESTREPO-LOPEZ, Juan Camilo; ORTIZ-ROYERO, Juan Carlos; OTERO-DIAZ, Luis  e  OSPINO-ORTIZ, Silvio Raúl. Suspended sediment load in Colombian Caribbean Rivers: Magnitude, trends and variability. Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2015, vol.39, n.153, pp.527-546. ISSN 0370-3908.  https://doi.org/10.18257/raccefyn.209.

The data on the monthly average of suspended sediment load from seven rivers in northern Colombia (Caribbean alluvial plain) draining into the Caribbean Sea were analysed to quantify the magnitudes, to estimate long-term trends, and to evaluate the variability patterns. These rivers deliver an average of ∼146.3 x106 t yr^-1 of suspended sediments to the Colombian Caribbean littoral. The largest sediment supply is provided by the Magdalena River, with a mean suspended sediment load of 142.6 x106 t yr^-1, which is 38% of the total fluvial discharge estimated for the Caribbean littoral. Between 2000 and 2010, the annual suspended sediment load of these rivers increased to 36%. The wavelet spectral analyses highlighted periods of intense variability between the periods of 1987-1990 and 1994-2002, where the major oscillation processes appeared simultaneously. The semi-annual, annual and quasi-decadal bands were the main factors controlling the suspended sediment load variability of these fluvial systems, whereas the quasi-biennial and interannual bands constituted second order sources of variability. The climatic/oceanographic drivers associated to the oscillations identified through the wavelet spectral analyses defined a medium/long term framework of variability for the suspended sediment load.

Palavras-chave : Suspended sediment load; Caribbean Sea; hydrologic variability; wavelet spectral analyses.

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