Detecting Glacier Dynamics During 2016–2024 Using Planet Imagery in the Upper Zarafshon River Basin, Tajikistan

The Upper Zarafshon River Basin (UZRB) in Tajikistan hosts numerous glaciers, of which the Zarafshon glacier is the largest and most important source of meltwater for both Tajikistan and Uzbekistan. In this study, we analyzed glacier retreat, surface displacement, and the evolution of supraglacial features from 2016 to 2024 using multi-temporal, high-resolution satellite imagery from Gaofen-2 and PlanetScope (80 cm and 3 m spatial resolution). We selected five representative glaciers-№ 168, 178, 185, 202, and 203 based on their size (greater than 1 km2) and hydrological significance. Our comprehensive investigation of the glaciers in 2024 includes data on glacier area, length, supraglacial lakes, and morphological classification. The results show a decrease in total glacier area from 254.1 km2 in 2016 to 252.8 km2 in 2024. Surface movement patterns, derived from visual and geomorphological assessments, reveal spatially heterogeneous displacement, especially in debris-covered areas. Supraglacial lakes and ponds showed dynamic changes, with the most significant expansion in 2022, driven by increased surface melt and subglacial hydrological reorganization. These findings highlight the need for ongoing glacier monitoring in the Zarafshon River Basin (ZRB) due to the significant implications that cryospheric changes hold for regional hydrology, water security, and the frequency of climate-induced natural hazards.