Incorporation of Glacier Mass Balance Modelling in the Variable Infiltration Capacity Hydrology Model, with Application to Western Canada

Abstract:

Mountain glaciers play an important role in the water budget of many basins in western North America. Glacier storage and melt strongly control the seasonality of runoff and can modulate inter-annual variability in glaciarized basins. In particular, glacier runoff can provide a substantial source of streamflow during dry summer months. The importance of glacier runoff from an ecological and water resource perspective, coupled with observations of glacier retreat over recent decades, provides the impetus for accurately simulating runoff from glaciarized regions. The ultimate goal is to derive a greater understanding of the hydrologic response to both climate change and climate variability via improved representation of the cryosphere in hydrologic models. In an effort to more skilfully simulate the cryospheric component of the hydrologic cycle in the mountainous terrain of western North America, we have embarked on a process of updating the macro-scale Variable Infiltration Capacity (VIC) hydrology model to include the ability to simulate glacier mass balance and glacier dynamics. This presentation, which deals with the first part of this effort, reveals progress to date in implementing a process-based representation of glacier accumulation, melt and runoff. We aim to describe the new VIC glacier mass balance model and to present results regarding the testing of the glacier mass balance, water storage and runoff algorithms. Model testing, calibration and validation will be accomplished by confronting the model with observed glacier mass balance and streamflow data collected from several monitoring sites within the western Canadian Cordillera. Challenges with respect to model calibration and application will also be discussed.