Establishing the emission inventory of biogenic volatile organic compounds and quantifying their contributions to O3 and PM2.5 in the Beijing-Tianjin-Hebei region

Abstract

O3 and PM2.5 pollution are prominent in the Beijing-Tianjin-Hebei (BTH) region, and volatile organic compounds (VOCs) are important precursors of both. However, few studies has been conducted to establish a high-precision BVOC emission inventory by vegetation types and species for the BTH region yet, and to further analyze the contribution of BVOC emissions to O3 and PM2.5 on this basis. This study established an emission inventory of biogenic volatile organic compounds (BVOCs) in the BTH region using two methods: (a) the coupled method of stock volume conversion and plant function types (PFTs) and (b) MEGAN method. The contributions from different vegetation types to O3 and PM2.5 in the BTH region in July 2018 were simulated with WRF-CMAQ and verified using the O3 and secondary organic aerosol (SOA) formation potential method. Relatively consistent results were obtained using the different inventory establishment and air quality impact analysis methods. Fruiters, crops, shrubs & grasslands, evergreen forests, and deciduous forests emitted 6.25%, 31.18%, 18.27%, 11.42%, and 32.88% of total BVOCs, respectively. The simulation results showed that BVOCs contributed 23.73% to O3 and 37.99% to SOA in the BTH region. Deciduous trees, such as poplar and Quercus, were the main contributors to O3, while Pinus tabulaefoimis and Quercus were the main contributors to SOA.