In 2002 China Urban Atmospheric Pollution, The Regional Characteristics

With the rapid development of the economy and urbanization, the regional characteristics of the urban air pollution in China has become dominant, and has attracted more attentions than before. The distribution of the urban air pollution over China and its regional characteristics among various defined areas are discusswd in this thesis with the monitoring data of 98 sites in 2002 coupled with NCEP reanalysis data.Urban air pollutions in North China, Middle China, East China and Southwest China are rather serious in 2002. Following the definition of regional air pollution, the 98 cites are divided into six regions: Region I is the Guanzhong city group in Shaanxi province, Region II is the area of Shanxi province, the northern part of Henan province and the southwest of Hebei province, Region III is the city group of Bejing, Tianjin and Tangshan, Region IV is the area around Chongqing, Chengdu and Guiyang cities, Region V is the area around Wuhan, Changsha and Nanchang cities, Region VI is the city group in the delta of Yangtze River. Among these six regions, SO₂ and PM10 pollution are most serious in Region II and the annual concentration of which is beyond level III of the national standard. NO₂ pollution is most serious in Region HI, especially in winter, with annual concentration of NO₂ about 0.059 mg/m³. The SO₂ and PM10 pollution are also very serious with the annual concentration beyond level III of the national standard. SO₂ and NO₂ pollution in Region I are no so serious but PM10 pollution is very serious, with the annual concentration of PM10 beyond level III of the national standard. Air pollution in the other three regions is relatively gentle compared with the former three regions, but PM10 pollution is also serious, the annual concentration of PM10 in each region reaches level III of the national standard. SO₂ and NO₂ pollution is serious in winter but gentle in summer in every cities ofChina especially in the northern cities, such pattern also can be found in PM10 pollution, but PM10 pollution will become very serious when encountered the dust storm in spring.By analyzing the weather pattern during the continuous and serious regional urban air pollution processes in 2002, it can be found that the serious polluted regions are influenced by the northeast airflow behind the East Asia trough at 500hpa and controlled by the high pressure system with slight surface wind and downward wind at 850hpa and surface. Such weather structure is the main weather pattern which causes the serious regional air pollution in China. The regional urban air pollution will become weak when the East Asia trough or the ridge moves eastward and passed.