Human activities have become the main driving force of groundwater decline in highly cultivated and mined area

Groundwater plays a vital role in agricultural production, industrial development and sustaining ecosystem in arid and semi-arid regions. Growing climatic change and intensified human activities increasingly threaten groundwater resources. However, the evolution of driving mechanisms on groundwater cycle under climate change and human pressure are currently unclear. This study developed a comprehensive framework integrating generalized additive model, clustering-based wavelet coherence, and water balance to quantitatively attribute groundwater storage (GWS) change in highly cultivated and mined area. Results reveal a significant GWS decline with an average rate of -1.02 cm/yr from 2003 to 2023. Seasonal and spatial analysis shows that GWS decline is more severe in summer and autumn, and predominantly concentrated in eastern Ordos and northern Yulin. Quantitative attribution indicates that human activities including groundwater withdrawal for irrigation, coal mining and afforestation, contributed 76.35 % to GWS decline, nearly three times 23.65 % contribution from climatic factors. Furthermore, as human activities intensified over time, climatic influence further weakened around 2015 and human impact continuously strengthened. Although precipitation and surface water recharge increased, the greater accelerated discharge led to GWS decline. Additionally, with the magnitude of GWS decline increasing, the influence of climatic factors gradually weakens, whereas the impact of human activities becomes increasingly dominant. These findings quantify the relative contributions of human and climatic factors to groundwater change and reveal the evolution of driving mechanisms on groundwater cycle in highly cultivated and mined area, providing a scientific basis for sustainable groundwater management and efficient water use in arid and semi-arid regions.