Background Dust pollution emerges as a major environmental challenge in the open-pit mining of coal mines. Ecological restoration has found widespread applications in mining areas as a crucial measure. However, there is a lack of systematic studies on the role of vegetation configuration in dust migration.

Methods Using the computational fluid dynamics (CFD) method for numerical simulation, this study constructed a comprehensive simulation framework incorporating wind field reconstruction, dust migration, and the dust retention capacity of vegetation. By setting different particle sizes and wind speeds, this study systematically analyzed dust migration patterns. Furthermore, vegetation configuration was introduced into the simulation framework as a variable, and its effects on wind field distribution and dust migration were investigated.

Results and Conclusions  The results indicate that the wind field distribution in a mining pit exhibited significant spatial heterogeneity. Specifically, the central portion of the wind field showed relatively uniform wind speeds, while dust was primarily concentrated in the vortex zones at its edges. The dust migration was jointly controlled by particle size and wind speed. In detail, dust of fine particles featured high dispersion capacity and could maintain significant concentrations even at a distance of hundreds of meters downwind, emerging as a primary factor in regional pollution. In contrast, dust of coarse particles was subjected to gravity, primarily settling at the pit bottom and near the surface. Therefore, it exerted a limited impact on distant areas. Under high wind speeds, some particles would be re-suspended by strong winds, thereby increasing the risk of long-distance migration. Vegetation configuration played an important role in dust retention. Regarding vegetation types, a mixed tree-shrub configuration performed best. Tall trees could reduce near-surface wind speeds, while low shrubs captured dust particles at the bottom. As a result, the combination of both reduced the peak concentration of inhalable particles by over 50%. In terms of vegetation layout, the staggered pattern created more favorable conditions for disrupting airflow channels compared to the linear pattern, leading to the formation of small-scale vortex zones with low wind speeds in the vegetation coverage areas. Therefore, this pattern prolonged the retention of particles and promoted their settling, reducing the average dust concentration by about 25% while significantly narrowing the range of local areas with high dust concentrations. The results of this study can serve as a theoretical guide for vegetation configuration optimization, as well as dust pollution prevention and control, in the ecological restoration of open-pit coal mines.