中文摘要：

度日模型通过正积温将冰雪消融和气温有效的联系到一起,模型中的关键参数是度日因子,即为正积温对应时段内的消融量.根据唐古拉山冬克玛底冰川2008年的实测资料,计算得到夏季消融期内冰川上的度日因子,并分析其空间变化规律.雪度日因子平均值为8.5mm.℃-1.d-1,大冬克玛底冰川雪冰混融度日因子和冰度日因子从海拔5330～5520m分别为4.5～9.6mm.℃-1.d-1和8.7～11.6mm.℃-1.d-1;小冬克玛底雪冰混融度日因子和冰度日因子从海拔5460～5710m分别为4.4～14.6mm.℃-1.d-1和9.9～16.1mm.℃-1.d-1.度日因子随海拔升高而递增,可能是随海拔增加,温度降低而太阳辐射增强所致.局地气候,地形等其它因素也使得度日因子在空间上的分布存在差异.

英文摘要：

The degree-day models are based on a specific relationship between snow or ice melting and the sum of daily mean temperatures above melting point,which is called the positive degree-day sum. The key parameter of degree-day model is the degree-day factor,which can be calculated from positive degree-day sum and ablation. Since air temperatures are the most readily available data,such models have been widely used in ice and snow melting computation,such as in hydrological modeling and climate sensitivity studies. And the basement of these studies is glacier mass balance computation. Degree-day factors for snow and ice ablation on the Dongkemadi Glacier in Tanggula Range are calculated based on observation data during the summer of 2008. The average value of snow degree-day factor is 8.5 mm·℃-1·d-1. The snow and ice ablation degree-day factors are 4.5-9.6 mm·℃-1·d-1 and the ice degree-day factors are 8.7-11.6 mm·℃-1·d-1 at the altitude ranging from 5 330 m to 5 520 m on the Da Dongkemadi. And the values are 4.4-14.6 mm·℃-1·d-1 and 9.9-16.1 mm·℃-1·d-1,respectively,at the altitude ranging from 5460 m to 5 710 m on the Xiao Dongkemadi. With the altitude rising,the degree-day factor at higher altitude is larger than at the lower altitude,which may be caused by larger radiation and lower positive degree-day sum in higher altitude. There are some other factors controlling the spatial distribution of degree-day factor,such as topographic factors （slope,shading and aspect angles）,local climatic environment and so on.