祁连山冷龙岭宁缠河3号冰川表面流速特征分析

2009年9月对祁连山冷龙岭宁缠河3号冰川外围建立控制网, 于冰川表面布设了13根标志杆, 随后分别于2010年7月、2010年9月再次对设立在冰川表面的花杆点进行测量, 获取2009/2010年度、2009年9月-2010年7月与2010年7-9月3个时段宁缠河3号冰川表面流速.结果显示: 2009/2010年度宁缠河3号冰川最大流速出现在海拔4 430 m附近, 为3.76 m·a^-1;2009年9月-2010年7月表面流速最大值出现在海拔4 430 m附近, 为0.32 m·月^-1;2010年7-9月最大流速出现在海拔4 380 m附近, 为0.47 m·月^-1.总体来看, 2009/2010年度宁缠河3号冰川纵剖面上流速变化较为缓和, 显示出流速随海拔变化而变化的规律. 但不同季节表面流速在纵剖面上的分布情况不同, 横剖面上主流线附近流速最大, 向冰川两边逐渐递减, 各观测点均平行于主流线方向向冰川末端运动, 表现出冰川运动一般规律. 在冰川表面运动速度观测区域内东南边缘流速略大于西北边缘, 同时与规模相近的冰川运动速度相比, 宁缠河3号冰川运动速度较大.

An Analysis of Flow Features of the Ningchan River Glacier No. 3 in the Qilian Mountains

In September 2009, the expedition established a geodetic chain around the Ningchan River Glacier No. 3, and 13 mark points were installed on the glacier surface for surveying glacier flow velocity. In July 2010 and September 2010, the mark points were surveyed again and again, and the surface flow velocities of the glacier were determined for the periods of 2009/2010, September 2009-July 2010 and July 2010-September 2010. It is found that the maximum surface flow velocity was 3.76 m·a^-1 (at the elevation of 4 430 m) for the periods of 2009/2010, 0.32 m·month^-1 (at the elevation of 4 430 m) in the time bucket from September 2009 to July 2010 and 0.47 m·month^-1 (at the elevation of 4 380 m) in the time bucket from July 2010 to September 2010. Overall, in 2009/2010, the variation of surface flow velocity was smaller and showed an elevation-dependence along a longitudinal section;along a transverse section the maximum surface flow velocity was close to the main flow line and gradually decreasing to the both sides. All flow direction was parallel to the main flow line, directing the glacier terminal. In the surveyed area, it is found that the surface flow velocities of the southeast edge were faster than those of the northwestern edge. As compared with other glaciers which have similar glacierized area, the flow velocity of the Ningchan River Glacier No. 3 is faster.