Spatial Distribution And Source Contributions Of PM_2.5 Concentrations In Jincheng Based On WRF/CALPUFF Model

Due to the growing economy and the increasing population,Jincheng City,as a resource-based city in Shanxi,is facing serious air pollution problems.In recent years,PM_2.5has become the primary pollutant in Jincheng,and it is threatening human health.Long-term exposure to the environment with high PM_2.5concentrations can cause the diseases of circulatory system and respiratory system.Therefore,the spatial distributions and source contribution of PM_2.5is very important for developing the measures of PM_2.5emission reduction.In order to evaluate the spatial distribution and source contributions of PM_2.5concentrations in Jincheng City.Based on the meteorological field data from the WRF model and the emission information of Jincheng pollution sources,this paper used the CALPUFF model system to simulate the PM_2.5concentrations in April,July,October and December,2017 in Jincheng,and compared the simulation results with the monitoring data from Jincheng,Zezhou and Gaoping monitoring stations,the results showed that the CALPUFF model slightly underestimates the monitoring data,but the simulation results are consistent with the variation trend of the monitoring data.This paper validated the effectiveness of simulation results from the CALPUFF model in simulating the near-field and far-field conditions with the help of the near-field tracing test results of the Taohuajiang Nuclear Power Plant site and the monitoring data of Jincheng City,and compared with the statistical parameters of FAC2,VG,MG,FB and NMSE under these two conditions.The results showed that the CALPUFF model can simulate the dispersion of pollutants under the near-field and far-field conditions.The simulated concentrations of the CALPUFF model showed an underestimation trend,but the model performance was acceptable.The CALPUFF model simulates the far-field dispersion is better than the near-field dispersion.Based on the simulation results of the CALPUFF model,this paper analyzed the spatial distribution and source contributions of PM_2.5concentrations in Jincheng area.The results showed that PM_2.5concentrations decrease gradually from the Jincheng city center.The concentration dispersion plumes of PM_2.5reach beyond the modeling domain,which would increase the PM_2.5pollution in other regions.Primary PM_2.5concentrations in December are significantly higher than those in July.However,the concentrations of secondary sulfate ions(SO₄^2-)and nitrate ions（NO₃^-）in July are higher than those in December.Overall,residential heating was the main contributor in December to the PM_2.5concentrations,accounting for 50%.Industrial processes and dust accounted for 18%and 14%,respectively.The urban area was the main contributor to the PM_2.5concentrations,accounting for 65%.Zezhou and Yangcheng were the important contributor to the PM_2.5concentrations,accounting for 18%and 10%,respectively.Lingchuan and Qinshui contributed little to the PM_2.5concentrations,both accounting for 2%.