Fluvial sediments: Main channel and floodplain interrelationships

AMSLER, MARIO LUIS; DRAGO, EDMUNDO CARLOS; PAIRA, ALDO RAÚL

The Middle Paraná River: Limnology of a Subtropical Wetland

Springer

Lugar: Heidelberg; Año: 2007; p. 123 - 142

ABSTRACT: This chapter deals with the sediment topic. The amount of the total sediment transport in the main channel and the principal secondary streams of the alluvial plain is focused distinguishing between the two fractions composing the solid discharge: the bed sediment (fine and medium sands in this case), and the finer sizes, silts and clays. These small particles predominate in the sediment transported through the system. They are essentially supplied by the Bermejo River from the Andean range, on the west side of the Paraná River basin. The silts and clays transport is considered with certain detail due to its quantity as well as the reductions verified in the amounts delivered by the upper Paraná River owing to anthropogenic factors occurred in the Brazilian areas of the basin. Those reductions reflected on the periodical sedimentation along the alluvial valley of the middle reach at several hydrological circumstances. This fact is stressed within the chapter conclusions together with the necessity of preserving the Bermejo River sediment supply in order to maintain the substratum properties, an essential fact if the Paraná River wetland sustainability is intended.