广州市氮氧化物的数值模拟及暴露影响评价

Numerical simulation and exposure assessment of NO_x in Guangzhou

主要介绍了大气暴露风险评价ADMER模式的模块组成及其主要功能,并利用该模式对广州地区常规的氮氧化物进行了暴露风险评价研究.利用中尺度气象模式模拟的5km气象场数据和收集整理的年平均污染排放源资料进行了大气污染扩散模拟计算.结果表明,无论是氮氧化物的浓度值还是其时空变化趋势,ADMER模式模拟的结果与实际观测均较一致,相关系数达0.76.氮氧化物的浓度高值出现在冬春季节,夏季的浓度相对较低,这主要是受气象场条件的影响.空间场上,氮氧化物的高值区位于广州地区的西南和中部,与工业大点源以及地面源排放的分布一致,而广州地区东北部氮氧化物的浓度值相对较低.在浓度评估的基础上,对暴露人口也进行了估算.由于广州是广东省的主要人口密集区,所以,定量化暴露人口对于进一步开展污染控制减排策略有一定的指示意义.

In this paper, an Atmospheric Dispersion Model for Exposure and Risk assessment （ADMER） is introduced and applied to the atmospheric dispersion of NOx in Guangzhou. Based on meteorological simulation data from the RAMS model and emission data from the SMOKE model, the ADMER model was used to estimate the long-term average spatiotemporal distribution of NOx concentrations. Comparisons between model outputs and observations, provided by automatic monitoring stations in Guangzhou, showed good agreement since a correlation coefficient 0.76 was obtained. Higher concentrations appeared in winter and spring, and lower concentrations in summer. These seasonal variations were mostly caused by the meteorological conditions. The regions with the higher concentrations of NOx were located in the southwest and central Guangzhou due to the distribution of large point source emissions and mobile emissions. The concentrations in the east and north of Guangzhou were comparatively low. Besides the concentrations, the populations exposed to high levels of NOx were also calculated. We estimate that over 3.6 million people were exposed to an annual average ambient NOx level that exceeded the Chinese national air quality standard. Because of the dense and large emission sources and population, an effective emission control strategy should be considered in the severely polluted regions.