Approaches to understanding the mechanical processes shaping river channels have historically been limited by the challenge of collecting data capable of delineating the complexity reflected in the fluid flow of water. At the same time, accurately capturing this complexity is critical for research in the fields of fluvial geomorphology, hydrology, and environmental engineering.

The study of fluid dynamics within the context of river environments reveals that fundamental properties, such as velocity, are highly variable over small spatial and temporal scales. The characteristics and behavior of flowing water determine how streams influence environments, such as the shape and structure of the channel, the erosive power exerted by the water, and the amount and character of the materials the river can transport. At watershed scales, time-averaged measurements of velocity in the downstream direction may provide reasonable estimates of reach-averaged stream power and the ability of the flowing water to perform mechanical work. However, where there is a need for higher-resolution measures of velocity and stream power to calculate bed shear stress or stream competence, define hydraulic microhabitat conditions, or generate deterministic models of stream channel adjustment, small-scale variations in the directionality and magnitude of flow vectors should be taken into account.