Construction Of CMAQ Pollution Source Inventory Based On SMOKE Model

With the development of urbanization and the continuous growth of energy consumption,air pollution has become an environmental problem that cannot be ignored.Various pollutants in the atmospheric environment are jointly affected by many factors such as meteorology and emissions.Changchun City is the capital city of Jilin Province,with dense industries and serious air pollution.Especially in winter,due to low temperature and stable atmospheric structure,the large amount of pollutants emitted by coal-fired heating further exacerbate the local pollution.In order to explore the characteristics of air pollution in Changchun,this thesis determined reasonable temporal,spatial and species allocation factors,and refined the MEIC inventory.At the same time,the parameters of SMOKE model were localized,and created the input files for the simulation based on the CMAQ model using different local input file of SMOKE.On this basis,the WRF-CMAQ model was used to simulate the PM_2.5 and PM₁₀concentrations in Changchun City in January 2015.After the analysis,the specific conclusions obtained are as follows:（1）This thesis conducted a localization study of the parameters in SMOKE model,compiled area code files,area temporal profile files,area spatial profile files,and area species profile files,etc.,and applied them to source inventory allocation in Changchun City.The results show that inventory allocation has higher accuracy.（2）Reasonable temporal allocation coefficients are determined based on different pollution source categories,and monthly inventories is allocated for hourly resolution.Using GDP,population density,land use,DOI data,road network,etc.to determine a reasonable spatial allocation factor,it has a certain degree of improvement compared with the single factor allocation method.（3）Based on the composition information of VOCs and PM_2.5 from different pollution sources,a species allocation factor based on model species was established and used for pollutant inventory construction and pollution simulation.（4）The WRF model was used to simulate the meteorological field in January 2015.The simulated values of temperature,air pressure and wind speed were very consistent with the measured values,and the peaks were well fitted.The air pressure is slightly lower than the monitoring value,and the wind speed is slightly higher than the monitoring value,and the simulation indicators are all within the required range.（5）The PM（particulate matter）concentration in January 2015 was simulated using the three-generation air quality model CMAQ.The results show that the verification indicators of each monitoring site are within a reasonable range.（6）The influencing factors were analyzed for the three periods of PM_2.5 heavy pollution in January.The results showed that unfavorable weather conditions were an important reason of heavy PM_2.5 pollution,which was mainly affected by the pollutant transport of the northern and western surrounding areas of Changchun City.In addition,local emissions contributed 61.81%to the PM_2.5 concentration in January,and the surrounding area contributed 38.19%.The contribution of local emissions of event 1,event 2 and event 3 was 55.19%,72.73%and 60.55%,respectively.