The change of Ningchan River Glacier No. 3 at Lenglongling, east Qilian Mountain, China

摘要

In July, 2009, we investigated the Ningchan River Glacier No. 3. A control network was established around the glacier and the expedition used a GPS-RTK to measure glacial area, terminal and surface altitude, and used an EKKO GPR to measure glacier thickness. We used a topographic map based on 1972 aerial photo, two TM images in 1995, 2009, and GPS-RTK data in 2009, to analyze the change of the Ningchan River Glacier No. 3 since 1972. Through analysis we found this glacier has been seriously shrinking over the past 37 years. The glacier terminal retreated about 6%, the area was reduced about 13.1%, the volume was reduced about 35.3%, and glacier shrinkage is mainly in the form of thinning. Glacier average thickness reduced from 36.8 m in 1972, to 27.4 m in 2009. Meteorological data around the study area shows that this region in recent decades has undergone differential warming which is the main reason for rapid glacier shrinkage.