###### Abstract  
The ecological environment is fundamental to human survival and development, and China has seen a historical shift from localized to widespread improvements in its ecological conditions. Aksu, a typical ecologically sensitive region in Xinjiang, China, is significant for the study of vegetation dynamics and their driving factors, which is crucial for ecological conservation. This study evaluates the spatiotemporal changes in vegetation coverage in Aksu from 2000 to 2020 using long-term Normalized Difference Vegetation Index (NDVI) data and trend analysis. Additionally, this study explores key factors influencing vegetation changes through correlation analysis with temperature, precipitation, and nighttime light data. The results indicate the following: (1) vegetation coverage in Aksu exhibits significant spatial heterogeneity, with annual NDVI increasing at a rate of 0.83% per year (\(p<0.05\)); (2) the influence of temperature and precipitation on NDVI was weakly correlated from 2000 to 2020; and (3) a strong positive correlation was found between nighttime light intensity and NDVI, suggesting that urban development plays a dominant role in vegetation change, while temperature and precipitation have comparatively minor impacts. The findings provide a scientific basis for ecological conservation and sustainable development in the region. vegetation change; NDVI; urbanization; remote sensing; Aksu; Xinjiang Study of Climate Factors and Urban Development  
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activities is comparatively limited. In arid regions, particularly in China's Xinjiang region, the impact of human-driven factors may be more pronounced than that of climate change, making it scientifically significant and practically valuable to study the effects of human activities on vegetation dynamics [20; 21]. In recent years, nighttime light data (such as Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) and Visible Infrared Imaging Radiometer Suite (VIIRS)) have been widely used in ecological and environmental research because they effectively reflect human activity intensity and urbanization processes [22; 23; 24]. Nighttime light data have proven to be an effective tool for quantifying the impacts of human activities such as urban expansion and agricultural development, providing a new perspective for environmental analysis [25; 26; 27; 28]. For example, in many arid and semi-arid regions, the growth of urban areas and agricultural irrigation may have significant positive or negative impacts on vegetation cover, often creating changes that diverge from traditional climate-driven patterns [29; 30]. In the Aksu region of Xinjiang (China), complex terrain, arid climate conditions, and a fragile ecological environment make vegetation particularly sensitive to human activities [31; 32]. The combined mechanisms of human and climate impacts need to be further explored [33; 34]. To address these research gaps, this study utilizes long-term NDVI data from 2000 to 2020 from the Moderate Resolution Imaging Spectroradiometer (MODIS, which has the advantages of rich spectral bands, high time resolution, wide coverage, free access, and so on) and systematically investigates the drivers of vegetation change in the Aksu region through correlation analyses with temperature, precipitation, and nighttime light data. Specifically, this study employs nighttime light data as an indicator of urbanization and human activity intensity, along with climate factors, to reveal the impacts of urban expansion and ecological engineering on vegetation cover. Unlike traditional studies focused solely on climatic factors, this study considers the dynamic role of human activities such as urban expansion and agricultural development and examines their spatial-temporal interactions with climate factors.