Assessing glacier melt contribution to streamflow at Universidad Glacier, central Andes of Chile
Glacier melt is an important source of water for high Andean rivers in central Chile, especially in dry years, when it can be an important contributor to flows during late summer and autumn. However, few studies have quantified glacier melt contribution to streamflow in this region. To address t...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-07-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://www.hydrol-earth-syst-sci.net/21/3249/2017/hess-21-3249-2017.pdf |
| Summary: | Glacier melt is an important source of water for high Andean rivers in
central Chile, especially in dry years, when it can be an important
contributor to flows during late summer and autumn. However, few studies have
quantified glacier melt contribution to streamflow in this region. To address
this shortcoming, we present an analysis of meteorological conditions and
ablation for Universidad Glacier, one of the largest valley glaciers in the
central Andes of Chile at the head of the Tinguiririca River, for the
2009–2010 ablation season. We used meteorological measurements from two
automatic weather stations installed on the glacier to drive a distributed
temperature-index and runoff routing model. The temperature-index model was
calibrated at the lower weather station site and showed good agreement with
melt estimates from an ablation stake and sonic ranger, and with a physically
based energy balance model. Total modelled glacier melt is compared with
river flow measurements at three sites located between 0.5 and 50 km
downstream. Universidad Glacier shows extremely high melt rates over the
ablation season which may exceed 10 m water equivalent in the lower ablation
area, representing between 10 and 13 % of the mean monthly streamflow at
the outlet of the Tinguiririca River Basin between December 2009 and
March 2010. This contribution rises to a monthly maximum of almost 20 %
in March 2010, demonstrating the importance of glacier runoff to streamflow,
particularly in dry years such as 2009–2010. The temperature-index approach
benefits from the availability of on-glacier meteorological data, enabling
the calculation of the local hourly variable lapse rate, and is suited to
high melt regimes, but would not be easily applicable to glaciers further
north in Chile where sublimation is more significant. |
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| ISSN: | 1027-5606 1607-7938 |