喀喇昆仑山西北部冰川运动速度地形控制特征

为了探讨地形和海拔对冰川季节和年平均运动速度的影响程度，利用2013-2018年GoLive数据与ASTER GDEM V2数据对喀喇昆仑山西北部3 389条冰川的地形（坡度、坡向、海拔）和冰川运动速度进行了综合分析。结果表明：冰川表面运动速度在物质平衡线处（3 970~4 770 m）达到最快，是冰川积极维持物质平衡的一种体现。坡度平缓地区在不同海拔下的冰川运动速度有明显的差别，但是不同坡度地区的冰川运动速度随海拔变化的趋势基本一致，均呈现先增大后减小。北坡冰川运动速度较平稳，南坡和西南坡的冰川运动速度（均为0.25 m·d^-1）最快并且变化幅度较大，最小值与最大值相差近4倍。冰川运动速度不是呈现单一的季节性变化，同时还会受到地形的控制。低海拔区域冰川运动速度在消融期（3-6月）较快，中海拔区域在消融前（11月至次年2月）较快。

Terrain dependence characteristics of glacier flow velocity in northwest of the Karakoram Mountains

In order to explore the terrain and altitude parameters affecting the seasonal and annual average flow velocity of glaciers, we extracted respectively the flow velocity of glaciers and the terrain factor from 2013-2018 GoLive and ASTER GDEM V2 data, integrated the regional terrain (slope gradient, aspect, altitude) and flow velocity of 3 389 glaciers in northwest of the Karakoram Mountains. It is found that the surface velocity of glacier reaches the fastest at the equilibrium line altitude (3 970-4 770 m), which is a manifestation of the glacier's positive mass balance. In the gentle area, the variation range is obviously dependent on altitude. However, the speed of glacier flow in different slope gradient areas has the same trend depending on altitude, first increasing and then decreasing. In this area, the glacier flow velocity on the north was relatively stable, while on the south (0.25 m·d^-1) and the southwest (0.25 m·d^-1), it was the fastest with a large amplitude of variation and a difference about 4 times between the minimum value and the maximum value. The glacier flow velocity does not show a single seasonal change, but also a dependence on terrain. The glacier flow velocity in the low altitude area is relatively fast during ablation (March to June), but in the middle altitude area, the glacier flow velocity is relatively fast before ablation (November to February).