A method for extracting disturbance distances of open-pit coal mining in arid regions based on comprehensive index

As China is shifting its focus of energy development westward, coal mining activities in arid desert regions such as Xinjiang are becoming increasingly frequent, placing substantial pressure on the regional ecological environment. To achieve precise management and restoration of mining areas, it is crucial to determine the disturbance distance of coal mining in arid regions. In this study, the disturbance distances of open-pit coal mining are extracted by comparing, along 36 directions of buffer transects from the pit's geometric center, the degree of temporal fluctuation of the composite indicator SurMEI at different distances, based on this indicator as it integrates vegetation, soil, and water. Results demonstrate that SurMEI is more effective in capturing ecological changes in arid regions and in delineating disturbance scopes compared to the normalized difference vegetation index (NDVI), with an overall identification accuracy of 91.25%. The intensity of mining disturbance was the most pronounced near the mining sites and gradually weakened with increasing distance. The disturbance distance in different directions ranged from 780 to 8970 meters, and the indirect disturbance distance obtained by subtracting the distance of mining-dumping land from the disturbance distance ranged from 200 to 1500 meters, with an average of 896.47 meters, reflecting the bounded nature of the impact range of coal mining activities. Additionally, the variation coefficient of indirect disturbance distances in different directions was 0.7753, reflecting the directional heterogeneity of mining impact on the ecological environment. These findings provide important guidance for monitoring the ecological quality of open-pit coal mining in arid regions and for achieving precise ecological restoration in mining areas.