Glacier distribution, changes, and water resource impacts in the Turpan−Hami Basin, Xinjiang, China

The Turpan−Hami Basin in Xinjiang is a resource−scarce area where glaciers are important water resources. Based on the data of the Chinese Glacier Inventory of Xinjiang in 2020 (CGI-XJ2020), this study analyzed and explained the distribution characteristics of glaciers in the Turpan−Hami Basin in 2020. Additionally, by integrating the updated First and Second Chinese Glacier Inventories, the study examined changes within the basin from 1962 to 2020. It also assessed the specific impact of glacier changes in the Hami region on the runoff of four typical basins. The results indicated that in 2020, the Turpan−Hami Basin contained 354 glaciers, covering an area of 155.82 km 2 and an estimated ice volume of 5.81 km 3 . Small glaciers (< 0.5 km 2 ) were the most numerous, accounting for 78% of the total, while glaciers ranging from 2.0 to 5.0 km 2 were the largest area, covering 39.37 km 2 , which represents 25.3% of the total glacier area. From 1962 to 2020, the glacier area decreased by 85.06 km 2 (35.3%). Between 1962 and 2009, the area decreased by 72.53 km 2 (30.11%), with an average annual retreat of 1.54 km 2 /a (0.64%/a). From 2009 to 2020, the area decreased by 12.53 km 2 (7.44%), and the average annual retreat slowed to 1.14 km 2 /a (0.68%/a). These results suggested that while the total glacier area continues to decline, the rate of decrease in absolute terms has slowed, whereas the relative rate of change has increased, indicating an accelerating trend in glacier melt. Climate-driven glacier changes have significantly impacted river hydrology and water resources in Hami. In basins without glaciers, runoff has shown a decreasing trend, suggesting that the positive effect of increased precipitation on runoff may not be sufficient to offset the negative impact of rising temperatures. In basins with smaller glaciers, the 'peak water' for glacier runoff likely occurred in the 1980s and 1990s, and water resources are expected to continue deteriorating. In contrast, basins with larger glaciers have not yet reached a 'peak water' and high flow is projected to persist for decades.