Wind zones map - Belgium

On the map of the national annex, the Belgian area is divided into four wind zones.

Fundamental value of the basic wind velocity vb,0	23m/s	24m/s	25m/s	26m/s

A variation have to be considered with the probability factor c_prob.

When the wind comes from a direction where the probability of occurrence of strong winds is less, a reduction can be considered with the directional factor c_dir.

You should also take in account the effect of the roughness of the terrain (vegetation / urbanization) and the effect of orography (terrain relief) to accurately determine the peak velocity pressure for each wind direction.

• 0 - Sea or coastal area exposed to the open sea.
• I - Lakes or area with negligible vegetation and without obstacles.
• II - Area with low vegetation such as grass and isolated obstacles (trees, buildings) with separations of at least 20 obstacle heights.
• III - Area with regular cover of vegetation or buildings or with isolated obstacles with separations of maximum 20 obstacle heights (such as villages, suburban terrain, permanent forest).
• IV - Area in which at least 15% of the surface is covered with buildings and their average height exceeds 15m.

See the features of Eurocodes Zoning for wind analysis in Belgium
Available in English/French, otherwise «Google Translate»!