2014—2020年科其喀尔巴西冰川运动速度年际与季节变化特征分析

Interannual and seasonal variation of flow velocity in Koxkar Baxi Glacier from 2014 to 2020

冰川运动是认识冰川性质的关键因素,也是冰川动力学的主要研究内容之一,能够为冰川资源合理利用及冰川灾害预警提供基础支撑。利用2014—2020年Landsat 8遥感影像,采用影像互相关方法,提取科其喀尔巴西冰川表面运动速度,并分析冰川表面运动速度的时空变化特征及影响因素。研究结果表明:(1)科其喀尔巴西冰川年均运动速度为0.04~0.05 m·d-1;(2)冰川运动速度由中流线向边缘逐渐减小,在消融区随着海拔的升高而加快,在积累区随着海拔的升高而降低,物质平衡线附近运动最快(0.17~0.20 m·d-1),与冰川运动的一般规律一致;(3)冰川运动速度具有“暖季快,冷季慢”的季节变化特征,暖季比冷季快16.67%;(4)2014—2020年冰川运动速度呈微弱减小趋势,平均运动速度减少约0.01 m·d-1;(5)气温、降水对冰川的运动速度季节波动及年际变化都具有一定的影响。

Glacier flow is a key factor in understanding the nature of glaciers, and it is also one of the main research contents of glacier dynamics, which can provide basic support for rational utilization of glacier resources and early warning of glacier disasters. There are many mountain glaciers located in the west of China. The study on the spatiotemporal variation of surface velocity of glaciers also has great significance for the social and economic development of the western China. Koxkar Baxi Glacier, locates on the southern slopes of the Tomur Peak, is a typical dendritic glacier. In order to obtain the conditions of Koxkar Baxi Glacier’ flow rates and its variation to further reveal the future of the variation of glacier, the spatiotemporal variability of glacier velocity was surveyed using correlation(COSI-Corr) method on Landsat imagery from 2014 to 2020. The results show that:(1) The average annual flow velocity of the Koxkar Baxi Glacier was 0.04~0.05 m·d-1 during 2014 to 2020.(2) The glacier reaches its maximum flow velocity near the center part, and the velocity decreased towards both lateral margins. In a longitudinal profile, ice flow velocity in the accumulation area increased down to the equilibrium line, while decreased towards the glacier terminal. The maximum velocity with 0.17~0.20 m·d-1 was found near the equilibrium line altitude.(3) The glacier flow velocity in warm seasons were 16.67% faster than that in cold seasons.(4) The glacier flow velocity from 2014 to 2020 showed a slight decreasing trend, and the average flow velocity decreased 0.01 m·d-1.(5) Temperature and precipitation had certain influence on the seasonal fluctuation and interannual variation of the flow velocity of the glacier.