Snow and glacier melt - a distributed energy balance model within a flood forecasting system

Abstract

Snowmelt is an important contribution to the generation of floods in Alpine rivers. Thus, a snow and glacier melt model has been developed as a component of an operational flood forecasting system for the Inn river in Tyrol. The model is based on a fully distributed energy balance approach. Because radiation energy input is the most important factor for snowmelt in high Alpine regions special attention is paid to the temporal variability of albedo during snow melt. It is modeled as a function of the total energy input the snowpack has received since the last snowfall. For firn and glacier ice a constant albedo is assumed. Internal processes within snow and firn are parameterized. Runoff from the glaciers and from the rest of the headwater catchments is modeled with parallel Nash cascades. The not glaciated parts of the Inn tributaries are modeled with a fundamentally upgraded BROOK hydrotope model.