Integrating landsat NDVI data with climate and anthropogenic factors reveals drivers of vegetation dynamics in the semi-arid Basin of Western China

In remote sensing research, vegetation dynamics are often used as indicators of ecosystem conditions, especially in semi-arid areas. The Wei River Basin (WRB) is a semi-arid region in western China prone to climate change and sensitive to the environment. Driven by climate change and human activities, particularly the recent reforestation projects, the environment and landscape of this region have undergone significant changes. However, the quantitative contributions of the driving factors to vegetation dynamics have not yet been well established. Here, we use a first-difference multiple regression model to separate and quantify the impacts of climate change and human activities on normalized difference vegetation index (NDVI) from 1998 to 2023. The results indicate that: (1) the growing season NDVI has significantly increased (slope = 0.006, R² = 0.85) during the previous 26 years. (2) The main factor limiting the improvement of NDVI is precipitation, accounting for 67.6% of the area (p < 0.05). (3) During 1998-2023, climate factors accounted for 27.5% of NDVI changes in the Wei River Basin (WRB), with precipitation contributing 63.2% of the climatic influence, making it the primary positive driver of vegetation growth. Meanwhile, anthropogenic factors contributed 72.5%, with ecological restoration projects promoting greening and urban expansion causing degradation. These findings provide a basis for future assessments of vegetation management strategies and ecological restoration policies under climate and anthropogenic pressures in semi-arid basins.