Influence of mining on vegetation in semi-arid areas of western China based on the coupling of above ground and below ground – A case study of Daliuta coalfield

Underground mining operations are known to result in extensive surface subsidence, introducing a multitude of disturbances to surface vegetation, with particularly severe environmental impacts in the fragile ecosystems of arid and semi-arid regions. This study focuses on the Daliuta mining area located in semi-arid zones, selecting four distinct areas for data analysis. Areas A, B, and C fall within the mining perimeter and have all been affected by mining-related disturbances. Following coal extraction, Areas A and B underwent artificial rehabilitation measures, including fracture infilling and sea buckthorn plantation; Area C was left in its natural state without any artificial interference. Area D, unaffected by mining activities, was designated as the control group. The research utilized 60 Landsat satellite images spanning from 1988 to 2022. Employing the Normalized Difference Vegetation Index (NDVI) and the Fractional Vegetation Cover (FVC), the study classified the experimental zone's vegetation cover and degradation into six levels, ranging from low to high. By comparing the average vegetation cover over an extended period, changes across different vegetation cover levels, and the degree of vegetation degradation before and after mining, the study assessed the impact of underground mining on surface vegetation. The conclusions drawn are as follows: Mining operations caused significant damage to the vegetation in Areas A and B, yet artificial restoration measures notably improved the vegetation quality, with an overcompensation effect observed in Area A, suggesting the potential for ecological restoration efforts to create a vegetative environment that exceeds its original condition in the long term. Mining activities also induced continuous ecological adverse effects in Area C, but the natural regeneration process progressively restored the vegetation to pre-mining levels over time. Based on these findings, the study reveals the spatiotemporal patterns of vegetation damage and recovery across different mining periods and land reclamation stages. It proposes a restoration strategy for mine areas in semi-arid regions that prioritizes natural regeneration supported by artificial guidance. This work provides valuable insights and guidance for assessing the impact of underground coal mining on surface vegetation in semi-arid areas, as well as for the rehabilitation and ecological reconstruction of mine areas, emphasizing the necessity and urgency of conducting environmental assessments and implementing restoration measures.