以祁连山西段大雪山和党河南山冰川为例,利用1957/1966航摄地形图、1994年Landsat TM遥感影像、2000年ASTER影像、2010年的SPOT5影像及数字高程模型,运用RS和GIS对祁连山西段大雪山和党河南山冰川变化进行研究。结果表明:1957/1966-2010年研究区冰川面积缩小了17.21%,冰储量减小了24.1%。其中,1957-2010年间大雪山冰川面积缩小了16.03%(0.30%/a),平均每条冰川缩小0.133 km~2,末端平均退缩181 m(3.4m/a),冰储量减小了22.4%; 1966-2010年间党河南山冰川面积缩小了18.32%(0.42%/a),平均每条冰川缩小0.111 km~2,末端平均退缩159 m (3.6 m/a),冰储量减小了25.7%。大雪山南北坡冰川面积分别减小了22.82%和15.51%,党河南山南北坡冰川面积分别减小了22.39%和16.76%,总体来看,南坡冰川退缩幅度强于北坡。分析认为,气温上升是研究区冰川退缩的主导因素。与祁连山东、中部冰川变化相比,研究区冰川面积缩小幅度相对较小,这是区域气候差异、冰川规模等因素综合作用的结果。
英文摘要:
Mountain glaciers are sensitive climate indicators and thus subject to monitoring of environmental and climate changes. Furthermore,glacier runoff is the major contributor to water resources that are used to support the sustainable development of the environment, industry, and agriculture in arid region. Most researches of glacier changes in the Qilian Mountains are focused on the East and Middle of Qilian Mountains. Research on large-scale and long-time glacier fluctuations in the West Qilian Mountain region is limited despite the fact that the glaciers in this region provide important water resources for local economic development. During the past decades,glaciers in the Western Qilian Mountains have experienced rapid shrinking primarily due to climatic warming. Impacts of the glaciers shrinkage on water resources have drawn wide attention. Taking this into account, glaciers in the Daxue Mountain and Danghenan Mountain were selected to study in this paper. Based on 1: 50 000 topographic maps in 1957/1966 (5 in 1957,14 in 1966),satellite images (Landsat TM in 1994,ASTER in 2000 and SPOT5 in 2010) and digital elevation model (DEM),the selected glaciers was extracted by using the remote sensing image processing and analyzing method,and the changes of glaciers in the study area were analyzed under the support of the geographic information systems technology. The results indicate that from 1957/1966 to 2010, the total area and ice volume for the investigated glaciers in the study area have reduced by 17.21% and 24.1%. It is also found that from 1957 to 2010, the total area and ice volume for the investigated glaciers (196) in the Daxue Mountain have reduced by 16.03% (0.30%/a) and 22.4%,with a mean reduction of 0.133 km~2 for the individual glacier,the glaciers retreated by 258 m (3.4 m/a). From 1966 to 2010, the total area and ice volume for the investigated glaciers (281) in the Danghenan Mountain have reduced by 18.32%(0.42%/a)and 25.7%,with a mean reduction of 0.111 km~2 for the individual glacier, the glaciers retreated by 159 m(3.6 m/a). The rate of glacier retreat on south slopes was faster than that on the north slopes. The area of glaciers in South and North slope of Daxue Mountain have reduced by 22.82% and 15.51%,the area of glaciers in South and North slope of Danghenan Mountain have reduced by 22.39% and 16.76%,respectively. By analyzing the general trend of climatic change of the study area, it was found that rapidly rising air temperature is likely to be the major factor causing the shrinkage of the glaciers in the study area. Compared with other glaciers in the Eastern and Middle Qilian Mountains,glaciers in the western Qilian Mountains appeared to be decreasing more slowly. The differences of glacier changes in the Eastern,Middle and Western Qilian Mountains are mainly due to the combination of climatic conditions and glacier sizes.