Hydrological processes in the Aksu River source region during the intense ablation period based on water chemistry and isotopes

Against the backdrop of global warming, the dynamics of glaciers and their water resources have significant implications for hydrological processes in the arid regions of Northwest China. The Aksu River, which is an essential inland river enriched by substantial meltwater contributions, plays a pivotal role in the economic, ecological, and social development of the region. Based on 231 water samples collected during the period of intense glacial ablation in 2023, this study conducted a comprehensive analysis of the hydrochemical and stable isotopic characteristics of the Little Kurgan glacial basin in the Aksu River source region. A Piper diagram classified the hydrochemical type of the river water as Calcium–Bicarbonate. Analysis based on a Gibbs diagram indicated that rock weathering is the predominant factor affecting the hydrochemical properties within the studied basin. Through application of principal component analysis and end-member mixing analysis, it was determined that the glacier meltwater contribution to runoff was 67%, 61%, and 55% in July, August, and September, respectively. The findings of this study reveal that glacier meltwater is the principal component of the river water, and highlight the critical impact of alterations in glacier ablation on the hydrological cycle within the Aksu River source region, which is vitally important for sustainable water resource management.