|Martinec, Jaroslav - PRIVATE CONSULTANT|
Submitted to: International Conference on Water Resources Engineering Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 7, 2007
Publication Date: August 20, 2007
Citation: Rango, A., Martinec, J., Roberts, R.T. 2007. Relative importance of glacier contributions to streamflow in a changing climate. In: Proceedings 2nd International Association of Science and Technology for Development (IASTED) International Conference Water Resources Management, August 20-22, 2007, Honolulu, Hawaii. p. 203-207. Interpretive Summary: Global warming has become a concern because of the potential impact on water supplies. In order to assess the future consequence on Streamflow, a hydrologic model that considers the contribution of rainfall, snowmelt, and glacier melt is required. The Snowmelt Runoff Model (SRM) has these features and it also has a formalized climate change algorithm that allows both temperature and precipitation to be modified. In a warmer climate of +4° C, glacier melt contributing to Streamflow will increase by 8.5% annually in the glacierized Illecillewaet basin in British Columbia. Precipitation changes can be even more dramatic, but there is no consensus on how precipitation will change in the future like there is for temperature. The contribution of a glacier to Streamflow will eventually diminish as glacier area decreases until the glacier eventually disappears. Water managers in glacierized basins need to plan for such changes in their basins.
Technical Abstract: The role of glaciers and snow in climate change-affected runoff is evaluated by taking into account the carryover of runoff and of unmelted snow from one hydrological year to another. This water balance is computed for the present climate and for future climates with changed temperatures and precipitation. With this procedure, the contribution of glaciers to the total runoff and the yearly loss of glacier ice in a warmer climate can be more accurately determined than by just considering the overall increase of annual runoff volume. The Illecillewaet Basin in British Columbia, Canada (1155 km2, 509–3150 m a.s.l.) was selected for this study because of a significant glacial melt component in the runoff. For a temperature increase of 4°C, an additional 134.2•106m3 of today’s glaciers (in terms of water) in this basin would be melted in a year. This amount would be reduced as the glacier area gradually diminishes in the next decades.