On the map of the national annex, the French metropolitan area is divided into four wind zones identified from 1 to 4. Amendment A3, published in April 2019, replaces the division by cantons into a division by municipalities.
Zone | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Fundamental value of the basic wind velocity vb,0 | 22m/s | 24m/s | 26m/s | 28m/s |
The French overseas departments, overseas territories and overseas collectivities each have a specific basic wind velocity.
Zone | French Guiana | Mayotte Island | Martinique Island | Reunion Island | Guadeloupe Island |
---|---|---|---|---|---|
Fundamental value of the basic wind velocityvb,0 | 17m/s | 30m/s | 32m/s | 34m/s | 36m/s |
Zone | New Caledonia | Wallis and Futuna | Saint Martin | Saint Barths | Saint Pierre and Miquelon |
---|---|---|---|---|---|
Fundamental value of the basic wind velocity vb,0 | 36m/s | 41.2m/s | 36m/s | 36m/s | 36m/s |
Wind zoning of Metropolitan France (2019-2024)
0 -
Sea or coastal area exposed to the open sea; lakes and water bodies covered by wind over a distance of at least 5km.
II -
Open field, with or without a few isolated obstacles (trees, buildings, etc.) separated from each other by more than their height x40.
IIIa -
Campaign with hedges; vineyards; grove; sparsely populated.
IIIb -
Urban or industrial areas; dense grove; orchards.
IV -
Urban areas with at least 15%% of the surface is covered with buildings whose average height is greater than 15m; forests.
Wind zoning of Metropolitan France (2019-2024) The terrain categories have been transposed to Caledonian landscapes. The reference to terrain category IV is removed and categories 0 to III of standard NF EN 1991-1-4 are illustrated by the photographs below :
0 -
Sea side.
II -
Open field.
IIIa -
Campaign with hedges.
IIIb -
Industrial areas.
Source: RCNC
See the features of Eurocodes Zoning for snow analysis in France
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Distances / Direction | At the place of construction | 500m | 1000m |
---|---|---|---|
North | 436 m | 360m | 407m |
Northeast | 405m | 465m | |
East | 456m | 473m | |
Southeast | 419m | 446m | |
South | 449m | 476m | |
Southwest | 432m | 411m | |
West | 360m | 468m | |
Northwest | 403m | 452m |
Sectors | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Categories | IIIa | IV | IV | IV |
NF EN 1991-1-3/NA (may 2007) + A1 (july 2011)
NF EN 1991-1-4/NA (march 2008) + A1 (july 2011) + A2 (september 2012) + A3 (april 2019)
Sectors | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Sector definition | from 35 ° to 125 ° | from 125 ° to 215 ° | from 215 ° to 305 ° | from 305 ° to 35 ° |
Fundamental value of the basic wind velocity vb,0 | 24.0m/s | |||
Shape parameter K | 0.2 | |||
Exponent n | 0.5 | |||
Annual probability of exceedence p | 0.01 | |||
Probability factor cprob | 1.038 | |||
Directional factor cdir | 0.7 | 1.0 | 1.0 | 1.0 |
Basic wind velocity vb | 17.4m/s | 24.9m/s | 24.9m/s | 24.9m/s |
Reference roughness length z0,II | 0.05m | |||
Roughness length z0 | 0.2m | 1.0m | 1.0m | 1.0m |
Terrain factor kr | 0.209 | 0.234 | 0.234 | 0.234 |
Height above ground z | 15.0m | |||
Minimum height zmin | 5.0m | 15.0m | 15.0m | 15.0m |
Roughness factor cr(z) | 0.904 | 0.635 | 0.635 | 0.635 |
Orography factor * co(z) | 1.0 | 1.0 | 1.0 | 1.0 |
Mean wind velocity vm(z) | 15.8m/s | 15.8m/s | 15.8m/s | 15.8m/s |
Turbulence factor kl | 0.97 | 0.854 | 0.854 | 0.854 |
Standard deviation of the turbulence σv | 3.544m/s | 4.989m/s | 4.989m/s | 4.989m/s |
Turbulence intensity Iv(z) | 0.225 | 0.315 | 0.315 | 0.315 |
Air density ρ | 1.225kg/m3 | |||
Exposure factor ce(z) | 2.102 | 1.292 | 1.292 | 1.292 |
Peak velocity pressure qp(z) | 392.0N/m2 | 491.5N/m2 | 491.5N/m2 | 491.5N/m2 |
Peak wind velocity for Serviceability Limit States vp(z),SLS | 91.1km/h | 102.0km/h | 102.0km/h | 102.0km/h |
Peak wind velocity for Ultimate Limit States vp(z),ULS | 111.5km/h | 124.9km/h | 124.9km/h | 124.9km/h |
Code of the Environment - Article D563-8-1 (09/01/2015) JORF n°0248 of 24/10/2010 text N°5