Hydraulic complexity at a large river confluence in the Amazon basin

摘要: Confluences are a classic feature in riverine networks with important ecological and morphological functions. A method to characterize the hydraulic complexity of river based on velocity gradients was applied, for high low flow conditions, Negro Solimoes Rivers confluence Amazon basin. The applied metrics M1 M2 approximate drag forces imposed aquatic organisms moving between 2 locations may identify potential habitat zones edges. Metric corresponded best patterns hydrodynamic zone, largest values entrance confluence, centered at mixing interface, generally decaying laterally toward banks longitudinally downstream distance. Seasonal decreases discharge magnitude Amazon, other basins analyzed this study, led increases metric M2. can some aspects heterogeneity contribute an explanation observations increased species richness basin confluences larger diversity increasing nodes networks.