Spatiotemporal Variation Characteristics of Coal Dust Pollution in the Baorixile Mining Area

• • Interannual coal dust pollution in the Baorixile mining area (2001-2024) followed a three-stage lifecycle pattern: fluctuating increase (2001-2010), significant decrease (2010-2016), and stabilization (2016-2024), with the average pollution degree peaking at 0.41 in 2010 and stabilizing at 0.18-0.22 thereafter, indicating effective mitigation after peak production. • • Seasonal analysis (2019-2023) revealed a unimodal intra-annual pattern: summer pollution was most severe, followed by autumn, spring, and winter, providing a temporal basis for season-specific dust control measures. • • Multi-year dust impact frequency (DIF) analysis (2001-2024) showed that the maximum impact range (DIF≥1) first expanded then contracted significantly, while the perennial impact area (DIF=4) migrated from the southeast to the central-western open-pit, demonstrating a shift in dust disturbance gravity and successful containment. • • Intra-annual DIF (2019-2024) exhibited a spatial gradient decreasing from the core operation area to the periphery, with high-frequency zones (DIF≥9) stably concentrated in the open-pit; the affected area decreased from 88.14 km² in 2019 to 72.84 km² in 2024, a 17.4% reduction, highlighting the efficacy of ongoing dust suppression.