Air Quality Numerical Simulation and Forecasting for Chengdu Based on WRF/CMAQ Model

An air quality numerical forecasting test was conducted for the Chengdu area,Sichuan Province,which explored several respects including preparing emission inventory data,testing different land use data,parameterized experiment for meteorological physical parameters and air quality forecasting. The result shows that the simulation of SO₂ and NO₂based on MODIS land use data are more valuable than the USGS ones. A suitable meteorological physical parameters scheme was found for Chengdu area. The result also indicates that the predictions of NO₂ and PM₁₀ whom were relatively less influenced by outside source emission have better simulations than that of SO₂. Due to the inaccuracy of time distribution parameters,there are significant differences between the temporal trends of simulation results and the monitoring results. Furthermore,underestimating the emission causes the simulation forecasting results to be less than monitoring results. Not considering the outside source emission and using of the point monitoring averaging value rather than area value to evaluate area simulations all contributed to the obvious differences between the simulation forecasting and monitoring results.