Author(s): Juan Camilo Restrepo; Jorge Pierini; Juan Carlos Ortíz; Kerstin Schrottke; Luís Otero; Julián Aguirre
Linked Author(s): Julián Aguirre Pe
Keywords: Streamflow variability; Hydrologic oscillations; ENSO; River discharges; Wavelet analyses
Abstract: Data of monthly averaged freshwater discharge from ten rivers in northern Colombia (Caribbean alluvial plain) ,draining into the Caribbean Sea, are analysed to quantify discharge magnitudes, to estimate long-term trends, and to evaluate the variability of discharge patterns. The rivers deliver~340. 9 km3yr-1of freshwater to the Caribbean Sea. The largest freshwater supply is provided by the Magdalena River with a mean discharge of 205. 1 km3 yr-1 at Calamar. This amounts to 26%of the total fluvial discharge into the Caribbean Sea. From 2000 to 2010, the annual streamflow of these rivers increased to 65%. Upward trends in statistical significance are found for the Mulatos, Canal del Dique, Magdalena, and Fundación Rivers. The concurrence of major oscillation processes and the maximum power of the 3-7year band fluctuation define a period of intense hydrological activity from approximately 1998 to 2002. The wavelet spectrum highlights a change in the variability patterns of fluvial systems between 2000 and 2010, characterised by a shift towards a quasi-decadal process (8-12 years) domain. The Intertropical Convergence Zone (ITCZ) ,El NiñoSouthern Oscillation (ENSO) events, and quasi-decadal climate processes are the main factors controlling the fluvial discharge variability of these fluvial systems.
Year: 2015