Estimation of region-varying snow drifting intensity over China considering local climatic conditions

Snow drifting is the main cause of unbalanced roof snow load, which is affected by the geometric features of the roof as well as many climatic factors. Except for the roof shape, some building codes have considered the impact of wind speed or air temperature when specifying the roof snow load coefficients. However, the separate consideration of wind speed or air temperature on roof snow load is inadequate. To obtain a more accurate estimation of roof snow distribution, it is essential to consider the joint effects of relevant climatic factors on roof snow load, and a quantitative parameter is desired to evaluate the severity of snow drifting from a statistical perspective. With this background, a model for estimating snow drifting intensity considering local climatic conditions was developed in this study, which is mainly based on a 2-dimensional snow transport model. The effects of climatic factors, such as snowfall, air temperature, wind speed, as well as the increasing cohesion between snow particles with the deposition age, are considered in this model. Using the developed model, snow drifting intensity over China was estimated, and the impact of climatic factors on snow drifting was analyzed. Statistical and extreme value analysis was then carried out for the estimated snow drifts, and a map of the snow drifting intensity, quantified by the 50-year snow drifting ratio, was developed for China. The derived spatial distribution of snow drifting intensity over the country could be a good reference for the possible specification of region-dependent roof snow coefficients.