Performance of complex snow cover descriptions in a distributed hydrological model system: A case study for the high Alpine terrain of the Berchtesgaden Alps

• Published in: Water resources research Vol. 49; no. 5; pp. 2619 - 2637
• Main Authors: Warscher, M., Strasser, U., Kraller, G., Marke, T., Franz, H., Kunstmann, H.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-05-2013; John Wiley & Sons, Inc
• Subjects: Alpine catchment; Alpine environments; Alpine regions; Climatic conditions; Energy balance; Freshwater; Hydrologic models; hydrological modeling; Hydrology; lateral snow transport; Meteorology; National parks; Regular; Remote sensing; Runoff; runoff generation; Runoff rates; Seasonal distribution; Snow; Snow accumulation; Snow cover; Snow depth; snow distribution; Snow-water equivalent; Snowmelt; snowmelt dynamics; Water availability; Water depth; Germany
• ISSN: 0043-1397; 1944-7973
• DOI: 10.1002/wrcr.20219

Key Points
Complex snow descriptions reproduce observed snow distribution
Energy balance method enhances modeling daily snowmelt and discharge variations
Simulating lateral snow transport improves runoff modeling in the catchment
Runoff generation in Alpine regions is typically affected by snow processes. Snow accumulation, storage, redistribution, and ablation control the availability of water. In this study, several robust parameterizations describing snow processes in Alpine environments were implemented in a fully distributed, physically based hydrological model. Snow cover development is simulated using different methods from a simple temperature index approach, followed by an energy balance scheme, to additionally accounting for gravitational and wind‐driven lateral snow redistribution. Test site for the study is the Berchtesgaden National Park (Bavarian Alps, Germany) which is characterized by extreme topography and climate conditions. The performance of the model system in reproducing snow cover dynamics and resulting discharge generation is analyzed and validated via measurements of snow water equivalent and snow depth, satellite‐based remote sensing data, and runoff gauge data. Model efficiency (the Nash‐Sutcliffe coefficient) for simulated runoff increases from 0.57 to 0.68 in a high Alpine headwater catchment and from 0.62 to 0.64 in total with increasing snow model complexity. In particular, the results show that the introduction of the energy balance scheme reproduces daily fluctuations in the snowmelt rates that trace down to the channel stream. These daily cycles measured in snowmelt and resulting runoff rates could not be reproduced by using the temperature index approach. In addition, accounting for lateral snow transport changes the seasonal distribution of modeled snowmelt amounts, which leads to a higher accuracy in modeling runoff characteristics.