摘要
2022年7月中国地质大学(武汉)冰川勘测组与登山组,在格拉丹东雪山开展了"第二次大学生长江源科考"工作.为详细分析该区域冰川时空特征信息,以此次科研数据为支撑,结合光学遥感影像解译、InSAR形变信息提取、激光雷达测高及高精度大地测量,进行了多源遥感影像融合处理研究.针对格拉丹东雪山及典型冰川,采用高分卫星GF1、GF6、GF7、ZY3与Landsat7遥感影像,利用空三加密、频域影像互相关匹配、波段比值法及目视解译,提取区域DOM、冰川面积及条数分布;利用Sentinel-1A、ICESat-2影像,以SAR影像空间域互相关偏移量追踪方法为支撑,分别提取冰川表面流速及高程变化;利用青海省域北斗CORS站点,采用Gamit/Globk双差无电离层组合模型、卫星星站差分(real-time extended,简称RTX)及RTK(real-time kinematic)方法,计算所有控制点三维空间坐标及高程异常值.结果表明:格拉丹东雪山共发育冰川512条,年均增长率为3.12％,面积1 111.96 km2,年均退缩速率为0.63％;姜根(古)迪如冰川 日均最大流速为0.25 cm/d,年均最大流速为91.25 cm/a,其南支最大退缩值、堆积值及年变化速率分别为-74.63 m、38.44 m、-5.29-3.09 m/a,北支最大退缩值、堆积值和年变化速率-39.17 m、35.74 m、-3.02～2.85 m/a;所有控制点中误差及区域似大地水准面精化模型精度均达到了mm级.研究成果可以为后续在该地区开展相关冰川研究工作提供数据支撑.
Abstract
[Objective]In July 2022(Beijing time),the glacier survey group and mountaineering group of the China University of Geosciences(Wuhan)performed the"Second University Students'Scientific Expedition to the Yangtze River"in the Geladandong Snow Mountain area.[Methods]To analyse the spatial and temporal charac-teristics of glaciers in this region,scientific research data were combined with optical remote sensing image interpre-tation,InSAR deformation information extraction,LiDAR altimetry measurements,and high-precision geodetic sur-vey data to conduct multisource remote sensing image fusion processing research.Aerial triangulation encryption,frequency domain image matching,the waveband ratio method,and visual interpretation were used to extract DOM,DSM,glacier area and number distribution information from high-resolution satellite GF1,GF6,GF7,ZY3,and Landsat 7 remote sensing images of Geladandong Snow Mountain and typical glaciers.Sentinel-1A and ICESat-2 im-ages were used,supported by the cross-correlation offset tracking method in the SAR image space domain,to extract glacier surface velocity and elevation changes,respectively.The 3D spatial coordinates and elevation outliers of all the control points were calculated for the BDS CORS station in Qinghai Province using the Gamit/Globk double difference ionospheric combination model,real-time extended(RTX),and real-time kinematic(RTK)tech-niques.[Results]The results revealed 512 glaciers in the Geladandong Snow Mountain area,with an average an-nual growth rate of 3.12％,an area of 1 111.96 km2,and an average annual retreat rate of 0.63％.The average daily maximum velocity of the Jianggen(gu)Diru glacier is 0.25 cm/d,and the average annual maximum velocity is 91.25 cm/a.The maximum retreat value,accumulation value and annual change rate of Jianggen(gu)Diru glacier on the south side and north side are-74.63 m,38.44 m,-5.29 m/a to 3.09 m/a,-39.17 m,35.74 m,-3.02 m/a to 2.85 m/a,respectively.The precision of the regional quasigeoid refinement model and the errors at all control sites both attained mm levels.[Conclusion]The aforementioned findings can provide data support for subsequent research on glaciers in this region.
基金项目
国家自然科学基金(42274012)
中国地质大学(武汉)长江源科考"三全育人"示范项目(2022171)
维普
万方数据