A comparison study of two snow models using data from different Alpine sites

The hydrological balance of an Alpine catchment is strongly affected by snowpack dynamics. Melt-water supplies a significant component of the annual water budget, both in terms of soil moisture and runoff, which play a critical role in floods generation and impact water resource management in snow - dominated basins. Several snow models have been developed with variable degrees of complexity, mainly depending on their target application and the availability of computational resources and data. According to the level of detail, snow models range from statistical snowmelt-runoff and degree-day methods using composite snow-soil or explicit snow layer(s), to physically-based and energy balance snow models, consisting of detailed internal snow-process schemes. Intermediate-complexity approaches have been widely developed. Nevertheless, an increasing model complexity does not necessarily entail improved model simulations. Here a multilayer energy balance snow module is presented. The model has been developed at CIMA Research Foundation for hydrological purposes. Snow observations supplied by three Alpine sites were used for the model calibration, whose methodology is here described. Preliminary results of a comparison analysis against the snow module developed at UPMC and IRSTEA are shown and discussed.