Updating the Brazilian wind speed map for structural design

Abstract

Several studies discuss how climate change influences precipitation, temperature, and wind loads. The wind loads, in particular, are a great concern in structural design, as their dynamic forces directly affect structural safety. In Brazilian codes, the wind loads are based on an isopleth map, created in 1977. The experimental data was collected on few weather stations (between 1950 and 1974) and treated statistically before being plotted. In view of this, a new assessment of the Brazilian code is necessary to evaluate the impact of climate change in the wind speeds and to develop a more thorough method, since a greater number of isopleths are more favorable for designing with safety. In this study, new data was collected from a greater number of weather stations, and a new approach to select and process wind-related data was proposed. The new method combined the maximum likelihood estimation with Gumbel distribution. The new method also adopted Kriging interpolation to georeference the wind speeds according to each station. The main advantage was to consider the extreme wind speed as a regionalized variable. After validating the results, a new isopleth map was created with updated data and greater precision. Finally, it could be seen a significant increase in the speed of extreme winds in the Brazilian territory. This confirmed the existing global trend discussed in the literature.