On building componentsʹ exposure to driving rain in Greece

In this paper, parameters related to building componentsʹ exposure to driving rain in Greece are investigated. Annual driving rain indices are calculated for 41 sites in Greece on the basis of average daily climatic data extending over several years, and of the – derived from the daily data – monthly and annual values of wind speed and rainfall. The differences among these three sets of annual driving rain indices are investigated with regard not only to the effect of using data of different time resolution on the estimated exposure levels, but also to the relative contribution of potential error sources to the observed differences among the calculated indices. Furthermore, with the use of the available daily data, the driving rain load burdening vertical building components during wetting periods (“absolute driving rain spells”-i.e. driving rain spells defined on the basis of daily intervals and of daily data for wind speed, regardless of wind direction, and rainfall) is calculated for the studied sites. Afterwards, the images produced for the relative exposure to driving rain at the examined sites by (a) the annual driving rain indices based on daily data and (b) the indices used to assess the rain load during wetting periods, are compared; these images are found to be highly correlated for Greece. The results derived throughout the study are discussed and further conclusions are drawn.