Dynamics and Biogeochemistry of River Corridors and Wetlands (Proceedings of symposium S4 held during the Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS Publ. 294, 2005, 151-158

1 Museo Argentino de Ciencias Naturales "B. Rivadavia", Av. Angel Gallardo 470 (1405),
Buenos Aires, Argentina

2 Fac. de Ingeniería (UBA), Departamento de Hidraúlica, Av. Las Heras 2214 (1127),
Buenos Aires. Argentina

Abstract Based on data from our own and other sources, we estimated the numerical relationships between suspended sediments (SS) and the Bermejo River streamflow, identified the months when these relationships were statistically significant, and investigated the impact suspended sediments in the Bermejo River exert on the hydrochemistry of the Paraná River. Correlations were observed between suspended sediments and streamflows in the Bermejo River during the months of maximum and minimum streamflow. There were positive correlations between suspended sediments in the Bermejo and in the Middle Paraná River with a 1-month time lag with respect to the month of maximum streamflow; and between the Bermejo River streamflow and SS and calcium concentrations in the Lower Paraná River with a 2-month time lag. In the Lower Paraná River, the concentration of soluble reactive phosphorus was very low (5 µg l^-1) during the receding limb of the Bermejo River hydrograph and the rising limb of the Paraná River hydrograph; it was high (138–157 µg l^-1) during the Bermejo River high water season. The Bermejo River’s huge yield (18 038 kg km^-2 day^-1) plays an important role in SS, calcium and phosphorus concentrations in the Lower Paraná River.

Key words calcium; hydrograph; Paraná River basin; phosphorus; streamflow; suspended sediments; time lag