Estimating Flow Dynamics and Sediment Transport Using Entropy Theory

Rivers and streams transport most of the world's freshwater. There are many cities located near large rivers and streams, where water plays an important role. In streams and rivers, hydraulic parameters can be calculated in a variety of ways, but velocity and discharge rates are of particular importance. The Entropy concept has been increasingly applied by researchers for estimating the velocity and discharge in rivers, especially for high flow conditions. The current research aims to provide a review of the application of the Entropy concept in rivers with different geometric and hydraulic characteristics. Entropy-based investigations shed light on how the 2D structure of velocity distribution for large river flows can be identified just by monitoring near surface velocities. The estimated flow velocity pattern well reflects the one gathered by ADCP across large and narrow transects during both low and relatively high flow conditions. Some examples can be inferred, respectively, from measurements analysis at Sajó and the Freiberger Mulde Rivers in Germany and the Negro and Solimões rivers in Amazon. Results highlighted that the entropy approach can accurately predict the velocity distribution and discharge rates just relying on the surface velocity with a percentage error lower than 15%. Also, the Entropy model was successfully applied to estimate bridge pier effects on river flow. Recently, the Entropy approach has been applied to calculate the shear velocity and bed load transport.