Quantitative analysis of the spatial gradient of vegetation disturbance caused by open-pit coal mining

Ecological protection and high-quality development in the Yellow River Basin are of great significance for safeguarding regional ecological security, promoting the green transformation of resource-based regions and enhancing ecological governance capacity in mining areas. Open-pit coal mining disturbance zones represent typical ecologically impacted areas in the Yellow River Basin. Activities such as excavation, stripping, dumping, transportation, and the construction of industrial sites can readily lead to alterations in surface morphology, vegetation degradation, and a decline in ecosystem service functions. To quantitatively identify the impact range and spatiotemporal evolution characteristics of open-pit coal mining on surrounding vegetation, this study takes the Weijiamao Open-pit Coal Mine in Jungar Banner, Inner Mongolia, as the research object. Based on Landsat remote sensing images from 2017 to 2025, the normalized difference vegetation index, vegetation disturbance intensity index, and Sen’s trend indicator are constructed. In combination with multi-ring buffer analysis and a distance-decay model, the spatial gradient, impact boundary, and temporal variation characteristics of vegetation disturbance around the mining area are analyzed. The results show that vegetation in the directly disturbed area and adjacent zones of the Weijiamao Open-pit Coal Mine is significantly affected by mining activities, whereas vegetation conditions in the peripheral areas are relatively better, indicating pronounced spatial heterogeneity in the ecological impacts of the mining area. With increasing distance from the mining boundary, the normalized difference vegetation index generally increases, while the vegetation disturbance intensity index continuously decreases, suggesting that the impact of open-pit coal mining on surrounding vegetation exhibited a clear distance-decay pattern. Specifically, the area less than 1.50 km is identified as the strongly disturbed zone, the area within 1.50-3.00 km as the disturbance transition zone, and disturbance tends to stabilize beyond 3.00 km. Vegetation disturbance intensity shows a negative exponential decay relationship with distance, with a theoretical impact boundary of approximately 3.66 km and a significant disturbance range of approximately 2.97 km. The Sen’s trend analysis results indicate the coexistence of vegetation degradation and restoration in the study area. Degraded areas are mainly concentrated within and near the mining area, while restored areas are mostly distributed in peripheral zones, suggesting that mining disturbance, ecological restoration, precipitation, and other natural factors jointly shaped the spatial pattern of vegetation change in the mining area. The findings provide a quantitative remote sensing basis for identifying ecological impact boundaries, assessing ecological damage delineating restoration zones, and promoting high-value land use in open-pit coal mining disturbance areas of the Yellow River Basin.