Glacier Mass Balance Observation in Barkrak Glacier, Western Tian Shan: Implications for Water Availability in Central Asia

Abstract

The cryospheric changes in mountainous region hold significant consequences for water resources in Central Asian countries, directly impacting human life. Monitoring glaciers in mountain regions is crucial to not only understand ongoing climate change but also to predict its impact on future water availability and variability. This study focuses on the annual mass balances of Barkrak glaciers in the Pskem River basin from 2017 to 2023.The contour line method was employed to extrapolate in situ observation to estimate annual glacier-wide mass balances. The results reveal a consistent negative trend throughout the observation period. For Barkrak Sredney (central branch), values ranged from -0.23 to -0.81 m w.e. a-1, while for the right branch of Barkrak Sredney, the range was - 0.44- - 0.66 m w.e. a-1. These findings suggest a gradual retreat of the glaciers, with accelerated melting observed particularly in the last 2-3 years. The negative mass balances underscore the vulnerability of Barkrak glaciers to ongoing climate changes. The obtained results, derived from direct measurements, will serve as crucial validation data for mass balances estimated through geodetic surveys and glacier modeling approaches. This validation process is essential for upscaling pilot measurement outputs to the basin scale, providing a comprehensive understanding of the glacier dynamics in the context of changing climate conditions.Keywords: Glacier mass balance, Central Asia, Water availability, Cryospheric changes, Glacier retreat, Pskem River basin