宝日希勒矿区煤炭粉尘污染时空变化特征OA

Open-pit coal mine generates substantial dust emissions,which severely impact both the mining area and its surrounding environment and exhibit significant dynamic variability.However,quantitative assessments of coal dust pollution extent and its evolution across multiple temporal scales remain insufficient.Utilizing the Google Earth Engine platform along with Landsat TM/ETM+/OLI/OLI-2 and Sentinel-2 MSI imagery from 2001 to 2024,the Enhanced Coal Dust Index and coal dust pollution degree were retrieved.Combined with the coal mine area's lifecycle stages,the temporal evolution and spatial heterogeneity of coal dust pollution in the Baorixile coal mine area were characterized.Based on annual and monthly remote sensing retrievals,Dust Impact Frequency metrics were constructed at multi-year and intra-annual scales to precisely quantify the spatial extent and frequency characteristics of coal dust pollution.The results showed that from 2001 to 2024,interannual coal dust pollution exhibited 3 distinct phases corresponding to the lifecycle:fluctuating increase,significant decline,and eventual stabilization.The average pollution level peaked at 0.41 in 2010 and stabilized between 0.18 and 0.22 during 2016-2024.The spatial pattern of pollution improved overall,contracting from widespread dispersion to concentration around open-pit areas and surface coal stockpiles.From 2019 to 2023,intra-annual coal dust pollution followed a trend of first increasing and then decreasing,with the highest pollution levels occurring in summer,followed by autumn,spring,and winter.Based on annual retrievals,6 periods of multi-year DIF maps were generated at 4-year intervals between 2001 and 2024.The maximum impact area(DIF≥1)first expanded and then contracted significantly,while the persistent impact area(DIF=4)shifted from the southeastern region to central-western open-pit areas,indicating a clear migration of dust disturbance centers and significant improvement due to dust control measures.Based on monthly retrievals,6 periods of intra-annual DIF maps were generated at 12-month intervals from 2019 to 2024.The spatial distribution of dust impact frequency exhibited a clear gradient,decreasing from core operational zones outward.High-frequency areas(DIF≥9)remained stably concentrated within open-pit mining areas,and the total impacted area decreased from 88.14 km2 in 2019 to 72.84 km2 in 2024.These findings provide a theoretical foundation and data support for scientifically understanding,monitoring,and evaluating the ecological conditions of mining areas and for formulating effective dust prevention and control strategies.