Modelling Snowmelt in Ungauged Catchments

Abstract

Temperature-based snowmelt models are simple to implement and tend to give goodresults in gauged basins. The situation is, however, different in ungauged basins, as the lack ofdischarge data precludes the calibration of the snowmelt parameters. The main objective of thisstudy was therefore to assess alternative approaches. This study compares the performance oftwo temperature-based snowmelt models (with and without an additional radiation term) and twoenergy-balance models with different data requirements in 312 catchments in the US. It considersthe impact of: (i) the meteorological forcing, by using two gridded datasets (Livneh and MERRA-2),(ii) different approaches for calibrating the snowmelt parameters (an a priori approach and onebased on Snow Data Assimilation System (SNODAS), a remote sensing-based product) and (iii) theparameterization and structure of the hydrological model used for transforming the snowmelt signalinto streamflow at the basin outlet. The results show that energy-balance-based approaches achievethe best results, closely followed by the temperature-based model including a radiation term andcalibrated with SNODAS data. It is also seen that data availability and quality influence the rankingof the snowmelt models.