Abstract: Based on the degree-day method, this paper established a simple distributed model to estimate the glacial runoff of a Tuomuer-type glacier. Considering the meltwater generations from snow, ice, debris-cover and ice-cliff of complex glacial underlying surface, the model demonstrates a robust capability to capture the glacial runoff variability. We set up a series of climatic conditions with changing surface air temperatures and precipitation to test the sensitivity of meltwater runoff to climate change. The results show that the changes in temperature yield great variations in meltwater runoff. A rising of 1℃ in temperature will lead to a runoff rising by 22.5%, while an increase of 2℃ will cause a meltwater discharge increase by 45.0%. On the contrary, a decline of temperatures by 1℃ and 2℃ will result in a runoff discharge dropping by 20.6% and 37.6%, respectively. Comparatively, changes in precipitation have weak influences on the glacial runoff.

Key words: Tuomuer-type glacier, glacial meltwater, sensitivity, temperature, precipitation, runoff