Global warming is accelerating the glacier and snow shrinkage in the Tien Shan. This study assesses the impacts of meltwater changes on soil moisture and hydrological processes using VIC-CAS, a glacier-expanded Variable Infiltration Capacity model, refined by improving the glacier-melt algorithm and incorporating a snowmelt pathway-tracking scheme. Projections were conducted across six glacierized basins in the Northern Tien Shan, with model calibration and validation using remote-sensing snow/glacier data and observed streamflow. By the late century (2080-2100), snowmelt runoff will decrease by one-third to two-thirds owing to decreasing snowfall. In the Bayingou River Basin (BRB), comprising large glaciers, glacier retreat is slow, and glacier runoff will increase until the 2060s. In contrast, glacier runoff in the other five basins, having surpassed the glacier runoff tipping points, will decline substantially. Glacier runoff remains the primary driver of annual streamflow variability with the BRB showing little change, while the other basins experience a one-fourth decrease in annual streamflow by the late 21st century. Reduced summer meltwater will exacerbate water scarcity, with summer streamflow declining by over one-third in basins with declining glacier runoff, and by nearly 10 % in the BRB. In mountainous areas above 2000 m, increased evapotranspiration is projected to reduce annual mean soil moisture by 10.5-16.3 % by the late century, with a more substantial decrease of 12.4-20 % during July-September due to reduced snowmelt. Continued glacier and snow shrinkage will intensify hydrological and ecological droughts, posing major challenges for water resource management and ecological protection.