Glacier meltwater contributions and glaciometeorological regime of the Illecillewaet River Basin, a headwaters catchment of the Upper Columbia River Basin, British Columbia, Canada
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2012
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Abstract
This thesis characterizes the main meteorological parameters influencing glacier snow- and ice-melt and quantifies recent glacier contributions to streamflow in the extensively glacierized Illecillewaet River Basin ( 4.9% of the basin), a sub-basin of the Columbia River Basin. Meteorological and mass balance data collected in 2009 on Illecillewaet Glacier are used to develop and constrain a distributed glacier melt model, based on temperature and absorbed solar radiation. Water isotopes were also collected to support melt contributions. The melt model is applied to the glaciers in the Illecillewaet basin for the summers of 2009-2011. Average glacier runoff for the period May-September is estimated at 122 ± 16 x 106 m3 for 2009-2011, approximately 10.6% of Illecillewaet River yields and in August making up 27% of the river flows. The glacial discharge is split almost equally between runoff from the seasonal snowpack and from melting of glacier ice/firn. For the lowest observed flow year in the basin, 2009, glacier contributions increased to 16% for May to September and 32% in August, with 82% of this glacier runoff derived from glacier storage (ice and firn). Climate sensitivity studies for Illecillewaet Glacier indicate that glacier mass balance is strongly influenced by summer temperature, with a net balance change of -0.6 m w.e. under a 1 °C warming. Winter precipitation increases of approximately 30% are needed to offset this. Winter mass balance measurements are scarce in this region, particularly for the high-elevation snowpack, introducing considerable uncertainty in the estimates of glacier mass balance. Summer balance and glacial runoff are better constrained, as these are most sensitive to summer temperature and cloud cover. These results are initial estimates, and long-term monitoring is essential to capture glacier and climate variability in the region, to refine glacier runoff, and to quantify its sensitivity to glacier retreat.
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Bibliography: p. 109-122
Some pages are in colour.
Some pages are in colour.
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Hirose, J. M. (2012). Glacier meltwater contributions and glaciometeorological regime of the Illecillewaet River Basin, a headwaters catchment of the Upper Columbia River Basin, British Columbia, Canada (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/4772