基于Landsat-8 OLI影像的天山南伊内里切克冰川2016年冰川表面运动状态提取与分析

The flow state of South Inylchek Glacier in the Tianshan Mountains in 2016:extraction and analysis based on Landsat-8 OLI image

利用Landsat-8 OLI传感器获取的2016年3-9月覆盖天山西段托木尔峰-汗腾格里地区的3期光学遥感影像数据,基于频谱归一化互相关算法提取并分析了该地区南伊内里切克冰川在最近一年消融期内不同时段的表面运动速度分布及其时空变化特征。研究结果表明:2016年消融期内靠近该冰川上游区域可观测到约为55 cm·d^(-1)最大运动速度;由于受到冰川下游物质补给量减弱、表碛物增多等因素影响造成冰川末端区域运动速度最小,整个消融期内冰川主体运动速度基本介于20~50 cm·d^(-1)之间,其平均运动速度约为35 cm·d^(-1)。而且,可观测到位于冰川上游区域在2016年3月9日至9月17日时段内,冰川运动速度呈递增趋势,相反位于冰川下游区域冰川运动速度呈现减弱趋势。另外,与早期研究对比可知,该冰川运动速度有所减缓且冰川末端明显处于退缩状态。

In this paper,the three-stage optical Landsat-8 OLI remote sensing imagery from March to September in 2016 were acquired,which covered the Tomur-Khan Tengri area in the western Tianshan Mountains. The flow velocity distribution on the South Inylchek Glacier,extracted by the spectral normalized cross-correlation algorithm,was analyzed for its temporal/spatial variation characteristics during the ablation period. The result showed that the maximum flow velocity up to ~ 55 cm d^（-1） could be observed in the upper part of the glacier during the ablation period of 2016. Due to the impact of both less ice mass supply and increasing debris cover on the glacier surface,the velocity was smallest at the terminus. During the whole ablation period,the flow velocity of glacier trunk was in between 20 cm d^（-1） and 50 cm d^（-1）,with an average of about 35 cm d^（-1）. Moreover,on the contrary to the decreasing velocity in the lower part of the glacier,the velocity in the upper part of the glacier had been increasing from 9 March to 17 Sept. 2016. In conclude,compared with the earlier studies,the glacier flow velocity has slowed down and the terminus has retreated obviously.