Abstract: This study addresses the issues of water scarcity and groundwater over-exploitation in the Tarim River basin,an arid region in northwestern China.By integrating remote sensing and ground-based observation data,we developed an accurate estimation model for groundwater storage in the region using water storage component decomposition techniques,aiming to provide a scientific basis for sustainable regional water resource management.Multi-source data,including terrestrial water storage (TWS)and surface water,were consolidated into a spatiotemporally consistent dataset through preprocessing and spatial resampling.A systematic analysis was conducted to examine the long-term trends,seasonal variations,and spatial distribution of groundwater storage from 2002 to 2024.The results reveal a significant declining trend in groundwater storage across the Tarim River basin,with an average annual reduction rate of -8.6 mm/a(p<0.01).The total cumulative loss over the study period exceeded 198 mm,equivalent to approximately 234 billion m³ of groundwater depletion for the entire basin.Spatially,the groundwater decline was most severe in the Kashgar Oasis,Korla Irrigation District,and Taitema Lake area,where the average annual loss rates generally exceeded -10 mm/a.This study provides critical data support for dynamic groundwater monitoring and rational water resource allocation in arid regions,while also offering a reference for future related research.

Key words: Tarim River basin, terrestrial water storage, surface water storage, groundwater storage, GRACE, water resource management