AUTHOR=Yang Xiaohui , Xiao Dengpan , Bai Huizi , Tang Jianzhao , Wang Wei 

TITLE=Spatiotemporal Distributions of PM2.5 Concentrations in the Beijing–Tianjin–Hebei Region From 2013 to 2020

JOURNAL=Frontiers in Environmental Science

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2022.842237

DOI=10.3389/fenvs.2022.842237

ISSN=2296-665X

ABSTRACT=Fine particulate matter (PM2.5) seriously affects the environment, climate and human health. Over the past decades, the Beijing-Tianjin-Hebei region (BTH) has been severely affected by pollutant gas and PM2.5 emissions caused by heavy industrial production, topography and other factors, and has been one of the most polluted areas in China. Currently, the long-term, large-scale and high spatial resolution monitoring PM2.5 concentrations ([PM2.5]) using satellite remote sensing technology is an important task for the prevention and control of air pollution. The aerosol optical depth (AOD) retrieved by satellites combined with a variety of auxiliary information was widely used to estimate [PM2.5]. In this study, a two-stage statistical regression (Linear Mixed Effect (LME) + Geographical Weight Regression (GWR)) model, combined with the latest high spatial resolution (1 km) AOD product, meteorological and land use parameters, was constructed to estimate [PM2.5] in BTH from 2013 to 2020. The model was fitted annually, and the ranges of coefficient of determination (R2), root-mean-squared prediction errors (RMSPE) and relative prediction error (RPE) for the model cross-validation were 0.85–0.95, 7.87–29.90 µg/m3 and 19.19–32.71%, respectively. Overall, the model obtained relatively good performance and could effectively estimate [PM2.5] in BTH. The [PM2.5] showed obvious temporal characteristic within a year (high in winter and low in summer) and spatial characteristic (high in the southern plain and low in the northern mountain). During the investigated period of 2013–2020, the high pollutant areas ([PM2.5] > 75 µg/m3) in 2020 significantly narrowed compared to 2013, and the annual average [PM2.5] in BTH fell below 55 µg/m3, with a drop of 54.04%. Especially the [PM2.5] in winter season dropped sharply from 2015 to 2017, and a steady decline after 2017. Our results suggested that significant achievements have been made in air pollution control over the past 8 years, and they still need to be maintained. The research can provide scientific basis and support for the prevention and control of air pollution in BTH and beyond.