Assessment of Climate Change Impacts on the Upper Athabasca River Flow: Application of a Snowmelt Runoff Model
Abstract
Climate change projections show continued warming which will intensify current runoff trends in snowmelt dominated catchments towards earlier spring peak flows and lower summer runoff. Quantifying these changes will assist in managing water resources and preparing for a new seasonal distribution of runoff. The Snowmelt Runoff Model (SRM), a simple conceptual hydrological model intended for application in snowmelt-dominated basins, is used to assess the potential effects of climate change on the Upper Athabasca River flow at Hinton. SRM utilizes remotely sensed snow cover information with the temperature-based degree-day method for simulating snowmelt. Despite being widely applied in glaciated basins, SRM studies have rarely explicitly accounted for the difference in Degree Day Factor (DDF) between glacier ice and snow, instead applying a zonal (elevation dependent) DDF. In this study, SRM is calibrated for the Upper Athabasca River Basin with separate snow and ice DDFs, satisfactorily simulating flows over the calibration (2000-2002, average NSE of 0.93) and validation (2003-2010, average NSE of 0.88) periods. The glacier DDF model produced comparable results to that of the zonal model. Incorporating the glacier DDF, either explicitly or through elevation dependence, is found to be essential for capturing inter-annual variability in melt conditions. Application of multiple climate change scenarios for the 2070-2080 period resulted in substantial decreases in May snow cover fraction and corresponding increases in May river flow. Winter months are projected to experience small increases in flow, though these increases represent sizable percentage increases relative to the baseline values. Results are consistent with historical trends and previous modelling studies in the region. These results confirm that SRM is a useful model for climate projections with minimal data requirements and relatively simple operation.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H51P1704D
- Keywords:
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- 1807 Climate impacts;
- HYDROLOGY;
- 1817 Extreme events;
- HYDROLOGY;
- 1860 Streamflow;
- HYDROLOGY;
- 1863 Snow and ice;
- HYDROLOGY