Against the background of climate warming, mountain glaciers in arid regions have continued to retreat. These changes are closely related not only to regional water supply and ecological security, but also to mountain-hazard risk assessment and adaptive management. Located in northern Xinjiang, the Junggar Inland Basin is an important glacierized area and a key source region for glacier and snow meltwater in northern Xinjiang. Glacier inventories provide a fundamental basis for documenting glacier resources, monitoring glacier change, and conducting long-term comparative studies. At present, regional-scale studies of long-term glacier change in the Junggar Inland Basin mainly rely on the First and Second Chinese Glacier Inventories (CGI-1 and CGI-2). However, most of the imagery used for these inventories was acquired before 2010, and the datasets are therefore limited by relatively outdated temporal coverage and comparatively low spatial resolution. As a result, they are insufficient for capturing the latest characteristics of glacier change in the study area.
In this study, the Junggar Inland Basin was selected as the study area to investigate the current glacier inventory, long-term glacier change, and the evolution of representative glaciers. Based on GF-1, GF-6, and ZY-3 imagery, together with COP-DEM and other auxiliary data, glacier boundaries were delineated through manual visual interpretation and GIS-based analysis, and the Glacier Inventory of the Junggar Inland Basin in 2020 (GI-JIB2020) was established. On this basis, the current glacier distribution in the study area was analyzed. Glacier changes during 1960–2020 were then comparatively examined using the revised CGI-1 and CGI-2 datasets and glacier-code matching results. In addition, long-term monitoring data from the Tianshan Glaciological Station and records from representative meteorological stations were used to analyze the evolution of typical glaciers and their climatic background. The main conclusions are as follows:
(1) Based on domestic high-resolution remote-sensing imagery and COP-DEM data, the Glacier Inventory of the Junggar Inland Basin in 2020 (GI-JIB2020) was established. The results show that, in 2020, there were 3,174 glaciers in the study area, with a total area of 1,645.69 km2 and an estimated ice volume of 73.77 km3. Among them, 74 were debris-covered glaciers, covering an area of 319.45 km2. The glaciers in the study area were generally dominated by small and medium-sized glaciers. A total of 2,502 glaciers were smaller than 0.5 km2, accounting for 78.90% of the total number, but only 21.20% of the total glacier area. Spatially, glaciers were mainly concentrated in Eren Habirga Mountain, the Manas River Basin, and the Ebinur Lake Basin. Topographically, they were mainly distributed within the 3,800–4,200 m elevation band, and north-facing (N) glaciers were the most developed. Overall, glacier distribution in the study area shows a clear pattern of concentration in high-mountain source regions, controlled mainly by mountain elevation, topographic conditions, slope aspect, and regional moisture transport.
(2) Through the consistent revision, fusion processing, and code matching of CGI-1, CGI-2, and GI-JIB2020, the influence of differences in data sources, spatial resolution, boundary interpretation, and ice-divide delineation among different inventories was reduced. On this basis, glacier changes during 1960–2020 were quantified using the glacier-code matching method. The results indicate that glacier area in the study area decreased from 2,343.03 km2 in 1960 to 1,635.39 km2 in 2020, representing a cumulative loss of 707.64 km2, a total retreat of 30.2%, and a mean annual retreat rate of 0.50%/a. Specifically, glacier area decreased by 596.02 km2 during 1960–2007, with a mean annual retreat rate of 0.54%/a, and further decreased by 111.62 km2 during 2007–2020, with a mean annual retreat rate of 0.49%/a. Over the past 60 years, 878 glaciers disappeared, corresponding to an area loss of 95.95 km2. These results indicate that glaciers in the Junggar Inland Basin have undergone sustained retreat since 1960.
(3) Glacier change in the study area showed clear differences related to glacier size, spatial location, and topographic setting. Small glaciers experienced stronger relative retreat and were more likely to disappear, whereas large glaciers showed lower relative retreat but greater absolute area loss. At the mountain-range scale, the largest glacier-area losses occurred in Eren Habirga Mountain, Borohoro Mountain, and Tengger Mountain, where glacier area decreased by 360.56 km2, 120.81 km2, and 96.62 km2, respectively, during 1960–2020. At the basin scale, glacier-area loss was most pronounced in the Manas River Basin (5Y73) and the Ebinur Lake Basin (5Y74), with decreases of 376.72 km2 and 257.18 km2, respectively. In contrast, marginal mountain ranges and small basins showed smaller absolute area losses but higher relative retreat rates. In terms of topography, glacier retreat was mainly concentrated within the 3,400–3,900 m elevation band. North-facing glaciers had larger absolute area losses, while glaciers on south- and west-facing slopes showed stronger relative retreat. These findings suggest that regional glacier retreat was influenced not only by climate warming, but also by glacier size composition, terminus elevation, and local topographic conditions.
(4) Analysis of representative meteorological records and typical monitored glaciers indicates that sustained glacier retreat in the study area was closely associated with pronounced climatic warming in recent decades. The annual mean air temperature increased at a rate of 0.254 °C per decade at Daxigou Meteorological Station during 1959–2018 and at a rate of 0.381 °C per decade at Kenswat Hydrological Station during 1980–2023. The warming signal was more prominent than changes in precipitation, suggesting that climate warming was the main climatic factor driving sustained glacier retreat in the study area, while precipitation change mainly played a moderating role. All four representative monitored glaciers showed continuous retreat, but their stage-specific evolution differed. Urumqi Glacier No. 1 was characterized by slow retreat in the early stage, marked shrinkage in the early 1990s, and intensified retreat in recent years. Haxilegen Glacier No. 51 and the Fan-Shaped Glacier both showed accelerated retreat in recent decades, whereas Sigong River Glacier No. 4 experienced relatively rapid retreat in the early stage, slower retreat in the middle stage, and renewed acceleration in recent years. Regional glacier inventories are effective for revealing long-term overall glacier change and spatial differences across the study area, while monitored glacier records help characterize the stage-specific evolution of individual glaciers. The combination of these two types of evidence provides a more comprehensive understanding of glacier retreat in the Junggar Inland Basin.
谷歌
火狐
