Developing a Glacier Hydrology Model for the Canadian Rockies

English Abstract:

Mountain snow and ice play important roles in hydrological cycle of alpine regions by regulating water availability downstream in terms of both quantity and its seasonal variations. Many hydrological models have been developed, but very few explicitly calculate the snow and ice energy-budget and snow redistribution to estimate melt rates and mass balance. In this study, a model was developed in the Cold Regions Hydrological Model platform (CRHM) to calculate the hydrology of a glaciated stream influenced by the energy and mass balance of Peyto Glacier Research Basin in the Canadian Rockies. The model includes a new energy-budget glacier module, a new avalanche module, novel deployment of a layered energy balance snowmelt model, and a blowing snow model to a glacier surface. The model considers redistribution of snow by wind and avalanche as well as full radiation and turbulent transfer energetics to snow and ice. The model was set up using hydrological response units that consider elevation bands, slope and aspect units, wind exposure and avalanche runout as well as the heterogeneity of non-glaciated terrain. Meteorological observations from the stations within the basin and nearby locations were used to drive the model. The model was tested by comparing the simulated mass balance to observations from snow and ice depth on ice and off ice stations. Snow redistribution components of the model were evaluated by falsification of the model. This evaluation process is used to assess the uncertainty in comprehensive, physically based glacier melt modelling. Such a modelling approach is important for quantifying the melt rates in a glaciated basin in the context of climate change and variability.