Evaluation of glacier runoff in Tailan basin by monthly degree-day model

Abstract

This study analyzes long-term climate and glacier runoff changes to examine climate change and glacier mass balance response over the past 47 years by applied a modified monthly degree-day models in Tailan basin, the Tianshan Mountains of China. The results show that the snow line altitude is much closed to that of observation or other's result, which suggested the model, is valid to evaluate the glacier runoff changes. The mass balance of Tailan glaciers is all below zero after 1982–1983, the total mass balance is −16.07m during 1961–2007. The average discharge of glacier during 2001–2007 has increased 25% than that between 1961 to 1990, about 2% contributed from the increased of precipitation, and another 23% contributed from the lost of glacier mass balance. The 0.4 degree increase of summer air temperature has made −235.7mm yearly mass balance compensate with 18.3mm increase of annual precipitation, which equal to −635mm per degree mass balance without increase of precipitation. The result reveals that the contribution of glacier runoff to Tailan hydrological station has remarkable increase after 1990, especially after 2000.