## 5 Conclusions  
This study utilized the kNDVI index calculated via Google Earth Engine to comprehensively analyze the spatiotemporal distribution and changes in vegetation growth in the Huojia mining area from 1999 to 2023. We conducted correlation analyses between precipitation, air temperature, and vegetation growth within the mine area. Additionally, we employed geographic detector models to investigate the spatial differentiation of vegetation growth influenced by land use, topography, soil properties, and coal mining thickness. Furthermore, the impact of land use changes on vegetation growth in the mine area was also examined. The main conclusions are as follows:  
1. This study demonstrates that kNDVI is more effective than NDVI in identifying areas with poor vegetation growth and exhibits greater sensitivity in monitoring vegetation dynamics. 2. Over the past 25 years, the overall trend of kNDVI has exhibited a fluctuating upward trajectory, with an annual average value of 0.121, indicating generally poor vegetation growth. The MK mutation test reveals that changes in kNDVI can be divided into three distinct stages: The first stage, from 1999 to 2011, exhibited a gradual upward trend in kNDVI, characterized by minimal spatial differentiation and generally poor vegetation growth. The second stage, from 2011 to 2018, saw a rapid increase in kNDVI, marked by significant spatial heterogeneity, with areas of relatively poor vegetation growth concentrated in the northwestern open-pit coal mines and the southeastern edge of the town. The third stage, from 2018 to 2023, witnessed a rapid decline in kNDVI, again exhibiting significant spatial differentiation, with areas of poor vegetation growth primarily located in the northwestern open-pit coal mines, the southeastern edge of the town, and the southeastern open-pit coal mine. 3. Over the past 25 years, the vegetation growth in the Huojitu mining area has shown a significant improvement overall, accounting for 57.35% of the total area. The degraded areas are mainly concentrated in the northwest and southeast of the mining area. The main reasons include the intensification of open-pit coal mining, urban and rural expansion, and the increase of engineering facilities. 4. Precipitation and air temperature are the primary natural factors influencing the fluctuating growth of vegetation in the Huojitu mining area, with precipitation being the dominant factor. Land use type is the principal determinant of spatial variations in vegetation growth, while topography significantly influences these variations. Additionally, coal mining thickness and soil nutrients such as soil organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) also play a role in shaping spatial variations in vegetation growth. The conversion of land use types contributes 46.45% to vegetation improvement, with the highest contribution coming from grassland-to-forest conversion. Conversely, land use changes contribute relatively less to vegetation degradation at 13.43%, with the main driver of degradation being the conversion of grassland to construction land. Conceptualization, Z.C. and Y.C. ; methodology, Y.C. ; software, X.Z. ; validation, S.W. and H.Z. ; formal analysis, Z.C. and Y.C. ; investigation, Z.Z. ; resources, Z.C. ; data curation, Y.C. ; writing--original draft preparation, Z.C. ; writing--review and editing, H.Z. ; visualization, C.H. ; supervision, Y.C. ; project administration, H.Z. ; funding acquisition, Y.Z. All authors have read and agreed to the published version of the manuscript. The authors declare that financial support was received for the research, authorship, and/or publication of this article.