The snow load in Europe and the climate change

It is often assumed that, as a consequence of global warming, a reduction of snow load on the ground should be expected. In reality, snow load is often depending on local orographic situations that can determine an increase of its height, even when the average snow height over the surrounding areas is reduced. Large snow loads on roofs during the winter season of 2005-2006 led to over 200 roof collapses in Central Europe. To proceed with the adaptation of the European standards for important buildings and infrastructures to the implications of climate change, the expected changes in the climatic loading shall be assessed in terms of the Eurocodes concept for characteristic values of variable climatic actions. The paper presents a procedure for derivation of snow load on ground from data on daily temperatures and precipitation. In addition, it allows to derive the characteristic snow loads from climate change projections and thus to evaluate the future trends in variation of snow loading. Analysis of these trends for the Italian territory is performed by comparing the results for several subsequent time periods of thirty years, with those obtained for the reference period 1951-1980. Results presented show a significant increase in the snow loading for the period 1981-2010 in many regions in north and east Italy in comparison with the reference period. It is suggested that a European project on snow load map shall be started, in order to help National Competent Authorities to redraft the national snow load maps for design with the Eurocodes.