祁连山东段宁缠河1号冰川和水管河4号冰川表面运动速度研究

Surface Flow Velocities of the Ningchanhe No.1 and Shuiguanhe No.4 Glaciers in the East Qilian Mountains

祁连山东段冷龙岭北坡冰川融水是河西走廊重要的水源补给,然而却少有现代冰川运动观测资料.通过在该区域宁缠河1号和水管河4号冰川布设花杆,观测了冰川表面的运动速度.结果表明:2010-2012年,面积较大的水管河4号冰川表面年平均运动速度(5.2m·a-1)要高于面积相对较小的宁缠河1号冰川(2.8m·a-1).水管河4号冰川最大运动速度出现在花杆观测区域的最上部(接近物质平衡线),宁缠河1号冰川最大运动速度出现在坡度较大的区域,说明冰川最大运动速度通常出现在平衡线附近,但还要考虑坡度等地形因素的影响.较之早期的观测资料,水管河4号和其他中国西部地区冰川的运动速度呈现出减缓趋势,可能是物质平衡持续亏损导致冰川厚度变薄的直接结果.

The glacier melt water in the northern slopes of the Lenglongling Mountain,located in the East Qilian Mountains,is the main water supply to the Hexi Corridor.However,there is little observation data about the modern glaciers＇ surface flow velocities in this area.So,the Ningchanhe No.1（NC No.1）Glacier and the Shuiguanhe No.4（SG No.4）Glacier surface flow velocities were investigated by surveying stakes on the glacier surfaces.The annual mean surface flow velocity of the SG No.4 Glacier（5.2 m·a-1）was higher than that of the NC No.1Glacier（2.8 m·a-1） during 2010-2012,due to the glacierized area of the former lager than that of the later.The maximum surface flow velocity of the SG No.4Glacier appeared at the higher elevation of the observed area（close to the equilibrium line altitude）,while the maximum velocity of the NC No.1 Glacier presented in the region with steeper slope.This shows that the maximum velocity of the glaciers commonly appears in the region close to the equilibrium line altitude;however,some topographic factors,such as slope etc.,should be taken into consideration.Compared with the historical data, it is found that there is decreasing tendency of the annual mean surface flow velocity on the SG No.4 Glacier,which may be attributed to the glacier thinning as a result of continuous loss of mass.