Prediction of snowmelt floods with a distributed hydrological model using a physical snow mass and energy balance approach

Modeling snowmelt is important for water resources management and the assessment of spring snowmelt flood risk. The objective of this study was to develop a physically based module for the WetSpa model to improve the simulation of snowmelt processes. The improved model is applied, calibrated, and verified on the Hornad watershed, upstream of Margecany, Western Carpathians, Slovakia, with 10 years of observed daily precipitation and air temperature, and estimated daily potential evaporation. Daily discharge data of the gauging station at Margecany is used for model calibration and verification. The model proves to predict accurately snow accumulation and snowmelt floods, although the parameters of the snow simulation module are preset and not adjusted by model calibration. In order to show the performance of the model, two particular snow accumulation and melt periods are discussed in detail. The relevant terms of the snowpack mass and energy balances as well as the related heat and mass transport processes are discussed. The study demonstrates that accurate snowmelt prediction based on a physically energy budget approach is possible with controlling parameters that do not need any calibration.