1990—2020年波曲流域冰川冰湖时空变化及其对气候变化的响应  

Temporal and spatial changes of glaciers and glacier lakes and its response to climate change in Poiqu Basin during 1990—2020

作　　者：王小丽[1] 周凌翔 王秀东 何颖 WANG Xiaoli;ZHOU Lingxiang;WANG Xiudong;HE Ying(School of Geography and Tourism,Chongqing Key Laboratory of GIS Application Research,Chongqing Normal University,Chongqing 401331,China)

机构地区：[1]重庆师范大学地理与旅游学院GIS应用研究重庆市高校重点实验室,重庆401331

出　　处：《干旱区地理》2024年第5期810-819,共10页Arid Land Geography

基　　金：国家自然科学基金项目(42071277);重庆市教育委员会人文社会科学研究项目(23SKID049);重庆市教委科学技术研究项目(KJQN202000525);重庆师范大学基金项目(23XWB032)资助。

摘　　要：基于Landsat TM/ETM+/OLI遥感影像和数字高程模型(DEM)数据,结合比值阈值法与目视解译提取了1990—2020年波曲流域冰川边界,同时利用归一化水体指数与目视解译提取波曲流域冰湖数据,分析近30 a波曲流域冰川冰湖空间分布与变化特征以及母冰川-冰湖相对位置变化关系,探究波曲流域冰川冰湖协同演化及其与气候变化的响应关系。结果表明:(1)1990—2020年波曲流域冰川加速退缩,尤其是近10 a来冰川加速退缩趋势更为显著;波曲流域冰川主要分布在海拔5500~6100 m范围内,规模上看,大规模(≥10 km^(2))冰川数量保持稳定,小规模(≤0.5 km^(2))冰川数量呈增加趋势。(2)近30 a波曲流域冰湖数量、面积均不断增加,冰湖面积扩张率为74.24%;冰湖主要分布在海拔4900~5300 m之间,大冰湖(≥0.07 km^(2))面积不断扩张;小冰湖(≤0.03 km^(2))数量增加显著。(3)与母冰川相连冰湖是最重要的冰湖扩张类型,该类型冰湖面积增长量占总冰湖增量的72.08%。(4)近30 a波曲流域气温缓慢上升,降水量总体略微下降。气温上升和降水量下降是造成冰川退缩重要因素,同时冰川融水促进冰湖扩张。通过波曲流域冰川-冰湖分布面积、变化特征及其协同演化关系的探究为流域冰川面积变化趋势和冰湖溃决灾害的预测及防治提供数据支撑。Utilizing Landsat TM/ETM+/OLI imagery and digital elevation model(DEM)data,this study extracted the boundaries of glaciers and glacial lakes in Poiqu Basin,Xigaze City,Xizang Autonomous Region,China from 1990 to 2020 through the ratio threshold method and visual interpretation.The distribution and variation of glaciers and glacial lakes over three decades were analyzed,alongside the exploration of their co-evolution and response to climate change within the basin.The findings revealed:(1)A notable acceleration in glacier shrinkage within the Poiqu Basin over the last decade,with glaciers primarily situated between 5500 m and 6100 m.While the count of large-scale glaciers(≥10 km^(2))remained constant,small-scale glaciers(≤0.5 km^(2))exhibited an upward trend.(2)Both the number and area of glacial lakes witnessed a significant increase,with an expansion rate of 74.24%.Predominantly located between 4900 m and 5300 m,the expansion was more pronounced in larger glacial lakes(≥0.07 km^(2)),whereas smaller lakes(≤0.03 km^(2))also saw a marked rise in numbers.(3)Glacial lakes connected to their parent glaciers emerged as the most significant type contributing to glacial lake expansion,registering a 72.08%increase.(4)The past 30 years have experienced a gradual temperature rise and a minor decline in precipitation.These climatic shifts,particularly the temperature increase and precipitation decrease,have been crucial in glacier retreat,while meltwater from glaciers has facilitated the expansion of glacial lakes.Through examining the distribution,changes,and interrelation of glaciers and glacial lakes in Poiqu Basin,this study aims to provide valuable data support for understanding glacier area dynamics and aiding in the prediction and mitigation of glacial lake outburst floods.

关 键 词：波曲流域 冰川退缩 冰湖扩张 气候响应 

分 类 号：P343.6[天文地球—水文科学] P467[天文地球—地球物理学]