1987-2018年祁连山冰川变化遥感监测及影响因子分析  

Using remote sensing images to monitor the glacier changes in Qilian Mountains during 1987-2018 and analyzing the impact factors

作　　者：汪赢政 李佳[1,2] 吴立新[1,2] 郭磊[1,2] 李建江 WANG Yingzheng;LI Jia;WU Lixin;GUO Lei;LI Jianjiang(School of Geosciences and Info-physics,Central South University,Changsha 410083,China;Laboratory of GeoHazards Perception,Cognition and Prediction,Central South University,Changsha 410083,China)

机构地区：[1]中南大学地球科学与信息物理学院,湖南长沙410083 [2]中南大学地灾感知认知预知研究室,湖南长沙410083

出　　处：《冰川冻土》2020年第2期344-356,共13页Journal of Glaciology and Geocryology

基　　金：国家重点研究计划“全球变化及应对”重点专项(2018YFA0605504);中国科学院战略性先导科技专项资助项目(XDA20100101);湖南省自然科学基金项目(2019JJ50761);国家自然科学基金项目(41904006);中南大学领军人才支持计划(506030101);中南大学中央高校基本科研业务费专项资金(2019zzts637)资助;湖湘高层次人才聚集工程项目(2018RS3013)。

摘　　要：祁连山冰川融水是维系我国西北地区生态平衡的重要因素。为评估祁连山冰川在全球气候变暖背景下的状态,利用Landsat-TM、ETM+、OLI等遥感影像,基于波段比值阈值法提取1987-2018年共计7期冰川边界进行时序变化分析。结果显示:近31年来祁连山冰川面积从2 080.39km2退缩到1 442.09km2,年均退缩率达0.99%,相比1956-1990年间的退缩率(0.58%)大幅增加;近31年来冰川物质平衡线高度稳步上升;冰川主要分布在海拔4 700~5 100m之间,冰川退缩随海拔降低而增加;约93%的冰川的面积小于2.0km2,小于0.1km2的冰川的总数和总面积呈增加态势;0.5~1.0km2的冰川退缩最快,年均退缩率达1.53%,而大于10.0km2的冰川退缩最慢,年均退缩率为0.59%;祁连山冰川退缩主要由夏季均温升高引起,且最近十年间冰川呈现出加速退缩的态势。Glacier meltwater from Qilian Mountains plays an important role in maintaining the ecological balance in northwest China. In order to cognize the glacier change caused by climate warming in Qilian Mountains,we adopted Landsat images(TM,ETM+ and OLI)and band ratio threshold method to extract seven terms of glacier boundaries between1987 and2018,and interpreted the time series of glacier boundaries combining with topographic and climatic data. The results show:(1)During recent31 years,the area of glacier in Qilian Mountains has shrank from2 080.39 km2 to1 442.09 km2,corresponding to an annual rate of0.99%,which is significantly higher than the retreat rate(0.58%)from1956 to1990;(2)The equilibrium-line altitude has increased steadily during recent31 years;(3)The glaciers are mainly distributed between4 700 and5 100 m a. s. l.,and the intensity of glacier shrinkage increases as the altitude decreases;(4)About93% glaciers have an area below2.0 km2;the total number and area of glaciers small than0.1 km2 are increasing;(5)The glaciers between0.5 km2 and1.0 km2 experienced the fastest shrinkage,with an average annual retreat rate of1.53%,while that larger than10.0 km2 experienced the slowest shrinkage,with an average annual retreat rate of0.59%;(6)The glacier shrinkage in Qilian Mountains is mainly caused by the rise of summer temperature,and more importantly,the glacier shrinkage has intensified during the last decade.

关 键 词：祁连山 冰川退缩 遥感 LANDSAT 气候 

分 类 号：P343.6[天文地球—水文科学]