| 岗纳楼冰川表面流速时空变化特征提取及分析 |
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| 引用本文： | 周中正,许才军,刘洋,熊露雲.岗纳楼冰川表面流速时空变化特征提取及分析[J].武汉大学学报(信息科学版),2022,47(2):226-233. |
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| 作者姓名： | 周中正 许才军 刘洋 熊露雲 |
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| 作者单位： | 1.武汉大学测绘学院，湖北 武汉，430079 |
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| 基金项目： | 国家自然科学基金42074007国家自然科学基金41874011国家自然科学基金41721003国家重点研发计划2018YFC1503603 |
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| 摘 要： | 冰川表面流速是反映冰川动态变化的重要指标,能够为冰川物质平衡提供重要信息.利用2016年的13景Sentinel-1A影像和合成孔径雷达(synthetic aperture radar,SAR)偏移量追踪法测定岗纳楼冰川表面流速场,并根据地表温度是否大于0℃将其分为冰封期(10月—次年3月)和消融期(4月—9月).其...
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| 关 键 词： | 岗纳楼冰川 冰川表面流速 时空变化特征 合成孔径雷达 偏移量追踪法 "压缩-舒张"流 |
| 收稿时间： | 2021-03-30 |
Extraction and Analysis of Temporal-Spatial Variation Characteristics of Surface Velocity of the Gangnalou Glacier |
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| Affiliation: | 1.School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China2.Key Laboratory of Geophysical Geodesy, Ministry of Natural Resources, Wuhan 430079, China3.Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, Wuhan University, Wuhan 430079, China |
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| Abstract: | Objectives The temporal-spatial variation characteristic of the glacier surface velocity is an important indicator of dynamic change of glacier and can provide important information for glacier mass balance. Surface temperature, glacier bed slope and glacier altitude are all important factors that affect glacier surface velocity, and their respective effects need to be analyzed. Methods In this paper, the offset-tracking method was used to measure the surface velocity of the Gangnalou Glacier, based on high-resolution Sentinel-1A synthetic aperture radar (SAR) images ranging from January 2016 to December 2016. We divided the surface velocity into freezing period and ablation period based on whether surface temperature was greater than 0 ℃ or not. For further analysis, we extracted the central line glacier velocity, and then jointly used surface temperature and digital elevation model (DEM) to analyze the influences of temperature and glacier bed slope. Results The results showed that surface velocity of freezing period was more stable and central line glacier velocity was faster than that of boundary which tended to 0 m/a. SAR measurements were affected by glacier ablation, accumulation and motion, and showed that the maximum surface velocity was 65.43 m/a during freezing period and 46.28 m/a during ablation period. This surface velocity field showed a partitioning phenomenon in which the velocities of the middle and lower parts of glacier tongue were significantly different from that of the upper part during ablation period. Conclusions The surface velocity of the Gangnalou Glacier was affected by many complex factors, of which glacier ablation and glacier bed slope are main factors. The partitioning phenomenon in the ablation period could be better explained by increasing surface temperature and changing glacier altitude, which directly affected glacier ablation and accumulation. Additionally, by analyzing the effect of the glacier bed slope, we found that the Gangnalou Glacier followed the compressive and extending flow mode in the freezing period. |
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