Modeling of Interannual Snow Storage for Long-Term Simulation

Snow models in hydrologic engineering field have barely incorporated the long-term effect of the interannual snow storage such as glaciers because the time scale of glacier dynamics is much longer than those of river flow and seasonal snowmelt. It will be shown in the presentation that general energy and mass balance models for snow process may fail without consideration of the interannual snow storage effect. This study proposes an appropriate treatment for inland glaciers as systems in dynamic equilibrium that stay constant under a static climate condition. It is supposed that the snow/ice vertical movement from high elevation areas to valleys (lower elevation areas) by means of wind re-distribution, avalanches, and glaciation, may be considered as an equilibrator of the glacier system because it stimulates snow/ice ablation. The simplest implicit modeling of such a dynamic equilibrium snow system is introduced and discussed for the long-term snow simulation, and its demonstrative model application in Wyoming will be presented.