Voolusuunast

Voolusuunast is a term used in fluid dynamics and earth sciences to denote the dominant direction of fluid flow at a given location and moment. In practice, it refers to the principal orientation of the velocity vector, describing where the water or air is moving toward on average over a defined time interval. The concept is used in oceanography, river hydrology, meteorology and coastal engineering to summarize complex flow patterns for navigation, modeling or environmental assessment.

In Estonian usage, voolusuunast is often considered together with flow speed, yielding a flow vector defined by magnitude and direction; the direction is usually given as an azimuth or compass bearing, while the speed is in meters per second. The concept can vary with depth in a water body or with height in the atmosphere, so voolusuunast is typically described as part of a time- and space-varying vector field rather than a single fixed value.

Measurement and calculation of voolusuunast rely on data from instruments such as Acoustic Doppler Current Profilers (ADCPs), current meters, or surface drifters. The time window for determining the direction depends on the application, as diurnal and seasonal variability can shift orientation. Visualizations commonly present arrows or contours on maps and time-series to convey how direction changes over space and time.

Applications include navigation safety, pollutant dispersion modeling, harbor design, flood risk assessment and ecosystem studies. The term highlights that flow direction is a variable property influenced by winds, tides, bathymetry and other forcing, and is often used alongside speed and vertical structure to describe a flow field.