利用InSAR技术估计长江源冰川2000—2020年物质平衡  

Estimating glacier mass balance in the source region of the Yangtze River during 2000—2020 through InSAR

作　　者：李佳[1,2,3,4] 李志伟 钟文杰[1,3,4] 顾云杨[1,3,4] 李龙[5] 郭磊 冯娟娟 LI Jia;LI Zhiwei;ZHONG Wenjie;GU Yunyang;LI Long;GUO Lei;FENG Juanjuan(School of Geoscience and Info-physics,Central South University,Changsha 410083,China;State Key Laboratory of Geodesy and Earth s Dynamics,Wuhan 430077,China;Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University),Ministry of Education,Changsha 410083,China;Laboratory of Geo-hazards Perception,Cognition and Predication,Central South University,Changsha 410083,China;Qinghai Remote Sensing Center for Natural Resources,Xining 810001,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]大地测量与地球动力学国家重点实验室,湖北武汉430077 [3]有色金属成矿预测与地质环境监测教育部重点实验室(中南大学),湖南长沙410083 [4]中南大学地灾感知认知预知研究室,湖南长沙410083 [5]青海省自然资源遥感中心,青海西宁810001

出　　处：《测绘学报》2024年第5期801-812,共12页Acta Geodaetica et Cartographica Sinica

基　　金：国家重点研发计划(2022YFB3903602);国家自然科学基金(42374053);湖南省自然科学基金(2023JJ30656);大地测量与地球动力学国家重点实验室开放基金(SKLGED2023-2-3)。

摘　　要：本文以获取近20年长江源冰川物质平衡,揭示冰川物质平衡影响因素及冰川物质流失对河流径流量影响为目标开展研究。利用InSAR技术和双站TerraSAR-X/TanDEM-X影像生成两期覆盖长江源全域冰川的DEM,分别和SRTM DEM差分,去除高程差系统误差后获取长江源地区冰川2000—2012年和2000—2020年间的高分辨率冰川厚度变化,再结合冰川密度将厚度变化转为冰川物质平衡。估计结果与区域内冰川实地物质平衡监测结果仅相差0.03 m w.e.a^(-1),表明精度较高。结果显示长江源地区冰川在2000—2012年间的物质平衡为(-0.30±0.02)m w.e.a^(-1),在2000—2020年间为(-0.45±0.04)m w.e.a^(-1),2012—2020年间冰川消融相比2000—2012年间明显加速。推测夏季气温升高和夏季降水减少是冰川加速消融的主要原因。另外,长江源地区冰川消融速度存在从东南向西北递减的趋势,分析认为这一现象与西部地区温度更低,升温更慢,冰川海拔更高,积累区面积比例更高,冰面坡度更陡有关。2000—2020年间,沱沱河流域冰川物质损失量仅占沱沱河径流量的4.4%,而沱沱河与当曲流域的冰川物质损失量之和仅占通天河径流量的2.5%,表明当前冰川物质损失对长江上游径流量的影响较小。This paper aims to estimate glacier mass balance in the source region of the Yangtze River,to investigate the factors that affect glacier mass balance,and to reveal the impacts of glacier mass changes on the runoff of the rivers.In particular,the InSAR technique and bistatic TerraSAR-X/TanDEM-X images were utilized to generate two DEMs that cover most of glaciers in the source region of the Yangtze River.The new DEMs were then differenced with SRTM DEM to obtain glacier thickness changes during 2000—2012 and 2000—2020,and a glacier mass density was used to converted the glacier thickness changes into glacier mass balance.The discrepancy between the derived glacier mass balance and the field measured glacier mass balance is only 0.03 m w.e.a^(-1),indicating a high precision of the results.The glacier mass balance in source region of the Yangtze River during 2000—2012 and 2000—2020 were(-0.30±0.02)m w.e.a^(-1) and(-0.45±0.04)m w.e.a^(-1),respectively.Glacier melting during 2012—2020 apparently intensified relative to that during 2000—2012.Rise of summer temperature and decease of summer precipitation were deemed as the main cause of glacier mass loss.Moreover,the glacier melting rate decreases from the southeastern part to the northwestern part of the study area.Lower summer temperature,smaller temperature rising speed,higher glacier altitude,higher glacier accumulation area ratio,steeper glacier surface of the west area may account for this phenomenon.During 2000—2020,the glacier mass loss in the basin of the Tuotuo River contributed 4.4%of the runoff of the Tuotuo River,and those in the basins of the Tuotuo River and the Dangqu River contributed 2.5%of the runoff of the Tongtian River,indicating that glacier mass loss had slight impact on the runoff the upper reaches of the Yangtze River.

关 键 词：长江源 冰川物质平衡 TanDEM-X影像 消融 径流量 

分 类 号：P237[天文地球—摄影测量与遥感]