Spatial interpolation of extreme wind speeds based on code suggested values

The nominal design wind load in the National Building Code of Canada is specified based on the reference wind velocity pressures. These pressures are calculated using the estimated 50-year annual maximum (hourly-mean) wind speeds and are tabulated in NBCC-2005 for 639 locations and NBCC-2010 for 675 locations. For sites that are not covered by the tabulated locations, the reference wind velocity pressures or the corresponding 50-year return period values of the wind speed can be spatially interpolated using a deterministic or geostatistical method. However, the choice, and suitable of a method for such a task using the tabulated values is not clear and different methods can result in significantly different interpolated values. An assessment of the best suited method for interpolation of extreme wind speeds is carried out in this study. The assessment is based on the cross-validation statistical analysis, and considers that the extreme wind speeds reconstructed from the tabulated reference wind velocity pressures in the codes are valid and reflect adequately the climate condition in Canada. Recommendations based on the cross-validation results are provided for practical applications.