Hydrological response of two high altitude Swiss catchments to energy balance and temperature index melt schemes

• Published in: Polar Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: GlacierSnow; ice melting; Energy balance; High altitude; Snowpack model; Nash; Sutcliffe; Polar Science
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=15098; http://id.nii.ac.jp/1291/00015008/

Comparison of energy Balance (EB) and temperature Index (TI) snow/ice melt methods for glacio-hydrological modeling in the Alps has been the subject of numerous studies; however, the debate on which method is preferable under which conditions and for which application is still ongoing. In this study, both melting routines were tested within the complex numerical framework of the fully distributed model (Alpine3D) to analyze the differences. We included two high-altitude Swiss alpine glaciered catchments, which represent two distinct types of glaciers, namely cirque and valley glaciers, with different weather conditions, topography, and data type. In this experiment, hydrological discharge in the Damma catchment was overestimated by the model with EB approach, which demonstrated Nash-Sutcliffe efficiency (NSE) of 0.61 mainly due to the overestimation of wind speed and longwave radiation. On the other hand, model with TI approach obtained a high NSE of 0.93, as this simple conceptual model does not rely on the abovementioned variables. For the Arolla catchment, better results were observed for both EB and TI melt schemes, with slight underestimation in modeled runoff as shown by NSEs of 0.89 and 0.77, respectively. The very satisfactory performance of EB model at the Arolla catchment is due to the use of input data sets from local weather stations that are more representative of the real catchment conditions. It was observed that the EB melt model performs better if driven with correct meteorological data sets from catchment-representative stations and that the calibration procedure of TI-melt model significantly affects its accuracy.