Spatiotemporal Variation of Vegetation Coverage and Its Driving Factors in the Beijing-Tianjin-Hebei Region Based on the Google Earth Engine Platform

Fractional Vegetation Cover (FVC) is an important indicator for evaluating the quality of regional ecological environments and sustainable development. As a core region of China's socio-economic development, the Beijing-Tianjin-Hebei area experiences vegetation dynamics that are significantly influenced by both intensive human activities and climate change. This study aims to reveal the spatiotemporal patterns of vegetation coverage in the Beijing-Tianjin-Hebei region from 2000 to 2023, and to identify the major climatic driving factors, with the goal of providing scientific support for regional ecological conservation and coordinated development policymaking. On this basis, a combination of methods including the Theil-Sen (Sen’s) slope estimator, Mann-Kendall (MK) test, Hurst exponent analysis, and partial correlation analysis was comprehensively applied. An in-depth analysis was conducted on the spatiotemporal dynamics of FVC, its future persistence, and its relationships with temperature and precipitation. The results indicate that: (1) Spatially, the FVC in the Beijing-Tianjin-Hebei region exhibits a distinct "northwest-high, southeast-low" distribution pattern. Temporally, the region experienced three phases: rapid increase (2000–2010), significant decline (2010–2015), and restorative growth (2015–2023).(2) Vegetation improvement areas (47.90%) and degradation areas (41.68%) show strong spatial heterogeneity, and up to 59.83% of the region exhibits anti-persistent characteristics in vegetation dynamics.(3) Precipitation serves as a positive driving factor for improved FVC, while the influence of temperature exhibits spatial heterogeneity. The results of this study highlight the need for future regional ecological management to shift from solely pursuing increases in vegetation coverage toward enhancing ecosystem quality and resilience, and to develop adaptive strategies to address potential ecological risks.