Hydrosedimentological characterization of a reach in the Forqueta River catchment, south Brazil

Abstract

We conducted an analysis on the hydrosedimentological characteristics of a section of the Forqueta River, located in southern Brazil. This river is part of a catchment area with steep slopes and fast-flowing water, and it is characterized by a gravel bed. A total of twenty-five sections were surveyed, representing three distinct morphologies (cascade, pool, and plane-bed). We estimated hydraulic variables and determined the characteristic diameters of sediments. The channel morphology in each section was observed throughout the course of a year, capturing seasonal variations. The findings of this study indicated that the cascade areas exhibited the highest values of sediment grain size, while the pool regions displayed greater variability in terms of channel morphology. We observed that higher values of channel slope had a significant influence on relative submergence, Darcy-Weisbach friction factor, and Manning's roughness coefficient. The pool morphology demonstrated higher granulometry values and a wider range of diameter values compared to the cascade morphology. No significant difference in the seasonality of the measurements was observed among the three different channel morphologies.