Modelling Hazardous Reduction Burnings and Bushfire Emission in Air Quality Model and Their Impacts on Health in the Greater Metropolitan Region of Sydney

Abstract

Modelling and forecasting of air pollution from bushfires or hazardous reduction burnings is important in providing information and allowing measures to be taken to reduce the exposure of people from harmful effect of air pollutants from fire events. In this work, the meteorological, chemical transport model and air quality models developed by the Commonwealth Scientific and Industrial Research Organisation of Australia are used in conjunction with the smoke emission model to simulate the formation and dispersion of particle aerosols (PM2.5) in the Greater Metropolitan Region of Sydney as the results of emission of different pollutant species from hazardous reduction burnings or from bushfires. The smoke emission model is based on a fire model describing two distinct fire behaviours: flaming and smothering. There are several schemes that can be used to estimate the emission factors of different emitted species from fire of various vegetation types. A comparison of these schemes is performed by comparing the air quality model output from air quality model with observation from monitoring stations in a case study, the May 2016 prescribed burning winter period, which caused elevated particle concentrations in the Sydney basin. The PM2.5 prediction over the Greater Metropolitan Region of Sydney from the forecasting modelling tool will then be used to calculate the population exposure and health impacts due to the May 2016 fire event as a case study. The three main health endpoints considered for health impacts are mortality, respiratory-related and cardiovascular hospitalisations. The results are comparable with other studies using non-modelling methods of determining the exposure and health impacts on this event.