windschaars

Windschaars is a term used in wind engineering and meteorology to describe short-lived, localized wind gusts that arise from rapid changes in wind speed and direction over small areas. These gusts are typically stronger than the surrounding wind and can occur near urban canyons, slopes, or around obstacles such as buildings or trees.

The term appears in Dutch-language wind science literature and is used in microclimatology and boundary-layer studies. Its precise origin is unclear, but it is commonly employed to distinguish transient gust events from steadier background winds.

Winds form when wind interacts with surface roughness, thermal gradients, or flow separation at obstacles, producing sharp accelerations or directional shifts over short distances. They may be organized by channeling in valleys or urban canyons and last from several seconds to a few minutes.

Measurement and impact: Windschaars are detected with fast-response instruments such as high-frequency anemometers and sonic sensors, and are used in microclimate assessments and wind-load calculations. They influence pedestrian comfort, wind maps, and the design of structures exposed to gusts.

Applications and examples: In practice, windschaars are considered in site assessments for tall buildings, bridges, roads, and wind-energy projects where abrupt gusts affect safety or performance.

See also: wind gust, wind shear, micrometeorology, urban climatology.