Research On Glacier Change And Surface Velocities Based On GPS/GIS/RS

Glacier is not only product of the climate, in which contains the message of both the earth climatic environment evolution and outpace environment, but also a sensitive indicator of climate change. Water is unique resource of the earth, and as showed in the latest data, the freshwater in Antarctic ice sheet, Greenland ice sheet and Mountain glaciers accounts for68.5percent of that on the earth. The glacier, as an kind of important freshwater resource, which is called natural reservoir of solid, is the headwater of many rivers. Located in Northwestern China, the glacier of the Qilian Mountains is the source of life oasis in Hexi corridor. With the global warming increasingly, most glaciers are continuously retreating, so the research of the change and movement of glacier has significance in social economy and people’s life, and provides parameter and calibration for correlation study.The study region of this paper is located at the north slope of Daxue Mountain of western Qilian mountains, the content of this paper is mainly about the Interpretation accuracy of the No.12Glacier based on TM image, the use of remote sensing image for glacier changes of Laohugou Watershed in the past50years and the monitoring glacier surface velocity of the No.12Glacier. We found that, since1957, the glaciers of Laohugou Watershed was ongoing retreat, which was most significant especially the period since the1990s, but the trend was slower during the past few years. The glaciers of Laohugou Watershed reduced11.59%in total area between1957-2009, the most significant change was between1999to2009, followed by1957-1994, and the minimal change has been found in1994-1999. From the glacier research of different scales, we drew a coincident conclusion with the overall situation. The smaller scale glaciers in study area was more sensitive to climate change, and the rate of area change increased with the decreasing area scale. The glacier area decreased mainly due to the increase of temperature. Increasing temperature might be the primary cause of aggravating of glacier retreat since the mid-1990s, which can be reelected by the reduction of glacier area to some extent. The main direction of glacier surface velocity was along the flow line of glacier, but it was also influenced by the glaciers terrain shape in some small deviations in the individual position. The glacier velocity increased with altitude below the confluence of Laohugou No.12glacier, and its peak value appeared at4680-4770m a.s.1of east branch during2011-2012; then with the elevation,glacier flow rate decreased. Above4870m a.s.1, it had a constant value.