Publication Date:
2011-09-03
Description:
The glacier mass balance, area change, and glacier runoff in the Yarkant River Basin (YRB) and the Beida River Basin (BRB) are estimated for the period from 1961 to 2006 by employing a modified monthly degree-day model. Comparisons between the simulated and observed mass balance, equilibrium line altitude, and glacier runoff suggest that the model can be used to analyze the long-term changes of glacier mass balance and runoff in the YRB and the BRB. The glacier mass balances of the YRB and the BYB both have a significantly decreasing trend with −4.39 mm a -1 and −8.15 mm a -1 from 1961 to 2006 owing to significantly increased ablation caused by increasing summer air temperatures, especially since 1996. The total runoff in glacier areas has a significant increasing trend with 0.23 × 10 8 m 3 a -1 and 0.02 × 10 8 m 3 a -1 in the YRB and the BRB, respectively. By comparing the mean mass balance during 1961 to 1986 and that during 1987 to 2006, the sensitivity of the glacier mass balance to temperature of the BRB is 0.33 m a -1 °C, nearly twice as much as that of the YRB 0.16 m a -1 °C. The primary cause of this difference of glacier temperature sensitivity in the YRB and the BRB is that the glacier elevation band area weighted altitude of the YRB is about 700 m higher than that of BRB. The glacier elevation band area weighted summer air temperature in the YRB is around 2 °C lower than that of the BRB. Therefore, the annual positive degree day of the YRB and the BRB increase by about 21.0 °C and 77.3 °C respectively when the summer air temperature increases by 1 °C , resulting into more glacier ablation and runoff in the BRB than in the YRB. Copyright © 2011 John Wiley & Sons, Ltd.
Print ISSN:
0885-6087
Electronic ISSN:
1099-1085
Topics:
Architecture, Civil Engineering, Surveying
,
Geography
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