The Application Of Universal Kriging In The Establishment Of PM_2.5 Spatial Model In Beijing

Objective:Although the country continues to take measures to control air pollution and improve air quality,PM2.5 is still the primary pollutant.A large number of epidemiological studies have found that PM2 5 can cause a variety of acute health effects.Therefore,understanding the spatial distribution characteristics of PM2.5,especially the daily distribution of PM2.5,can accurately assess the health effects and health risks of environmental air pollution exposure in the short term,and more effectively protect population health.Methods:Based on Beijing as the study area,this paper selected that Hourly PM2.5 concentration data of 35 environmental monitoring stations from 2015 to 2017,combining with the time and space of the corresponding four kinds of Aerosol Optical Depth data,eight kinds of meteorological data,ten different buffer size of density of road network density,distance from roads,building density and vegetation density data,through the data processing,correlation analysis and multivariate linear equation set up and residual kriging interpolation to establish universal kriging model for six urban areas in Beijing daily unknown position estimation of PM2.5 concentrations.Results:Correlation analysis was carried out for PM2.5 influencing factors,screening PM2.5 at 0.01 level(double side)on the significant correlation factor and Eliminate collinearity between each influence factor in the form of three steps,determine to model the impact factor of a total of eight:deep blue aerosol optical depth 10 km spatial resolution data,average pressure,average relative humidity,average air temperature,20-20 precipitation,the maximum wind speed,the density of buffer road 500 meters and 1500 meters buffer building density.Based on the above influence factors and the actual monitoring values of PM2.5,the universal kriging model of daily average PM2.5 in urban areas of Beijing was established.The mean value of R2 in the universal kriging model is 0.946,the mean value of RMSE is 13.9μg/m3,and the mean value of MAE is 8.63μg/m3.The statistical value was subject to the F test and t testConclusion:It has been proved that The model has a good calculation effect and can be used to calculate the average daily PM2.5 concentration in urban areas of Beijing.Data anomalies of impact factors will affect the accuracy of the universal kriging model,It is very important to strictly control the quality of influence factors in the process of establishing the universal kriging model.