Glacier changes in the Qilian Mountains over the past 60+ years: Multi-factor quantitative analysis of spatial heterogeneity and driving mechanisms.

Against the backdrop of global climate warming, glaciers in the Qilian Mountains have continued to retreat, yet existing monitoring data suffer from insufficient timeliness, and the analysis of influencing factors on glacier retreat lacks multi-element synergistic consideration. This study, based on data from two Chinese glacier inventories, glacier survey data of the Qilian Mountains in 2024, and long-term gridded temperature and precipitation data, comprehensively employs trend analysis, correlation analysis, and geographically weighted regression (GWR) to systematically examine the spatiotemporal evolution characteristics of glaciers and climatic elements in the Qilian Mountains from the 1960s to 2024, and to reveal the response mechanisms of glacier changes to climatic factors and local topographic factors. The results indicate that glaciers in the Qilian Mountains have exhibited a persistent retreat trend overall, with a total area retreat rate of 29.11%, and the retreat intensity has intensified in recent years. Spatial differences in glacier retreat rates are pronounced: in the middle and eastern parts, the Heihe, Shiyang, and Datong river basins have retreat rates exceeding 60%, whereas the western part, including the Haerteng and Shule river basins, has rates below 30%, displaying distinct differentiation patterns of "fast in the east, slow in the west", "fast in the south, slow in the north", and "fast at low elevations, slow at high elevations". Regional climate shows warming across the entire area with a slight increase in precipitation. The warming amplitude exhibits a pattern of higher in the west and lower in the east, with the greatest warming occurring in winter; precipitation increases are concentrated in summer and show a spatial pattern wherein the central and eastern parts receive more than the western part. Modulated by local conditions such as glacier elevation base and glacier size, the western Qilian Mountains experience stronger warming but relatively weaker glacier ablation, forming a spatially asymmetric pattern between climatic forcing and glacier response. Mechanism analysis reveals that temperature rise is the dominant driver of glacier retreat in the Qilian Mountains, and the slight increase in precipitation is insufficient to offset the mass loss from glacier ablation. The shift in precipitation phase induced by climate warming further exacerbates glacier loss through both material supply and energy input pathways. The GWR model confirms that large-scale climatic forcing determines the overall glacier retreat trend, while local factors such as elevation, aspect, slope, and glacier size regulate the sensitivity of glacier response to climate, collectively shaping the differentiated spatial pattern of glacier retreat. Based on these findings, it is recommended to implement differentiated glacier protection and water resource regulation strategies, strengthen climate change adaptation and collaborative governance, and improve glacier monitoring and early warning systems to address various risks arising from glacier ablation, thereby ensuring the ecological security and sustainable development of the inland river basins in the Hexi Corridor.