| Nowadays,with the continuous development of urbanization,China has become the most polluted area of aerosols,PM2.5 become the primary pollutant in most regions.Our government attaches great importance to air quality problems.PM2 5 is included in the newly revised "ambient air quality standards" in February 2012.Inhaled PM2.5 can cause serious impact on human health,the knowledge of spatial distribution of atmospheric particulates may be still the academic focus and problems to be solved for a long time.Although traditional method of site monitoring can accurately detect the local PM2.5 mass concentration,it is unable to forecast the quality of PM2.5 concentrations in a wide range of spatial distribution.in this context,Nanjing City,as a sever contamination of PM2.5,should deeply realize the characteristics of PM2.5 pollution,and on this basis,analyzing the impact on the PM2.5 concentration combined with land use and meteorological factor and so on.It can provide basis for scientific understanding and addressing regional air pollution problems,and promote harmonious development of the urban land use and the atmospheric environment in a more scientific way of land use.The characteristic on time and space separation of PM2.5 in Nanjing is obtained by the method of GIS and statistical analysis.The 2013 PM2.5 concentration data of Nanjing city is used as the basic data,Creating 500-2500km buffer zone Land use regression,and establishing land use regression model based on geographical weighting(GWR)and mixed geographical weighting(MGWR method).20 predictors of influence PM2.5 mass concentration including meteorological factor,land use factor,topography factor and other factors was selected.Draw the following conclusions:(1)PM2.5 concentration in Nanjing has obvious spatial and temporal characteristics.Select day,month,quarter as time scales,then find PM2.5 concentration has obvious difference in different seasons.PM2.5 pollution is most severe in winter,in autumn and spring,its concentration is much lower,the lowest is in summer.Select monitoring as special scales,Olympic Sports Center,Ruijin Road and Maigaoqiao have high PM2.5 concentration;Shanxi Road,Zhonghuamen and Xianlin University Town have low PM2.5 concentration.(2)the results show that R2 avarage value(0.84)and R2 Adjusted avarage value(0.80)for MGWR models were superior than R2 avarage value(0.83)and R2 Adjusted avarage value(0.79)for GWR models,there were 3.7 differences between both AIC index.The result indicate that using LUR model to simulate the large-scale area of near surface PM2.5 concentrations is effective.Forecasting method based on MGWR is better than GWR.The method provided in this paper has a certain reference value for the further research of PM2.5 estimation model.(3)According to the results of the simulation of the spatial distribution of PM2.5 concentrations of Nanjing,the high and low place of PM2.5 concentrations are relatively fixed in the four quarters.The Xuanwu district,Qinhuai district and Gulou district,as the central area of Nanjing,have relatively high population and traffic flow,so PM2.5 concentration is relatively higher.The concentration of PM2.5 in the northwest of Qixia district where is industrial areas is also high.Jianye district and Yuhua district are the main edge areas,and the economic development is inferior to downtown area,population density is slightly lower,so PM2.5 pollution is lighter. |
PDF Full Text Request