Objective This paper aims to reveal the spatiotemporal evolution of vegetation and its main influencing factors in the lower reaches of the Tarim River under ecological water conveyance from 2000 to 2023, and to provide a basis for ecological water regulation and restoration in arid regions.

Method Based on ecological water conveyance volume and the comprehensive vegetation index (CVI) from 2000 to 2023, the spatiotemporal changes in vegetation coverage, spatial and temporal coefficients of variation, hotspot and coldspot patterns, and abrupt changes were analyzed. Geodetector was used to identify the main environmental factors influencing vegetation spatial distribution and their interactions.

Result During the study period, the proportion of low-vegetation-coverage area decreased from 98.6% to 75.6%, while high-coverage areas expanded along both sides of the river and locally formed continuous green corridors. The area ratio of hotspots to coldspots was 1.6∶1.0. The mean spatial and temporal coefficients of variation of CVI were 0.03 and 0.07, respectively. Among significant abrupt changes, 76.3% were classified as “interrupted increase a”, and abrupt changes were relatively concentrated in 2012, corresponding temporally to the phased reduction in ecological water conveyance that year. Depth to groundwater had the greatest explanatory power for vegetation spatial distribution (q = 0.346), and the interaction between depth to groundwater and evapotranspiration reached 0.452.

Conclusion Ecological water conveyance promoted desert vegetation recovery by improving riparian groundwater and other moisture conditions, but long-term stable vegetation growth remained highly dependent on continuous water supply. Maintaining relatively stable hydrological regulation is beneficial for consolidating ecological restoration achievements in arid regions.