Windlage

Windlage refers to the wind field affecting a location, object, or structure. The term, derived from German for wind and position, is used in wind engineering and meteorology to describe the combination of wind direction, speed, vertical profile, and turbulence as modified by terrain, buildings, and other obstacles. Understanding windlage is essential for evaluating wind loads, designing safe structures, and optimizing the placement of wind-energy devices.

Windlage is characterized by several components: the prevailing wind direction, the mean and gust speeds, and the vertical and lateral variations of wind, often represented by a wind profile and a wind rose. Local features such as hills, valleys, and urban canyons create sheltering, channeling, or acceleration effects that change the windage relative to a reference location. Turbulence intensity and gust characteristics are also part of the windlage assessment, influencing dynamic responses of structures and equipment.

Data for assessing windlage come from weather stations, tall measurement towers, lidar or sodar instruments, and atmospheric models. Analysts use wind roses, time-series analyses, and computational fluid dynamics to map the wind field and estimate turbulence levels. In practice, windlage informs decisions in architectural design for wind loads, in the siting and operation of wind turbines, and in urban planning to mitigate wind-related discomfort or safety risks.

See also: wind field, wind loading, boundary layer meteorology, wind energy, urban climatology.