长三角区域城市间一次污染跨界影响

Trans-boundary primary air pollution between cities in the Yangtze River Delta

长三角城市群作为我国三大经济圈之一,高强度的能源消耗致使区域大气污染问题十分突出.为了定量弄清城市之间一次污染传输情况,以长三角15个城市的污染排放清单、MM5气象场为基础,利用CALPUFF空气质量模型,模拟测算了长三角区域内城市间一次污染跨界输送影响.结果显示,环太湖地区的上海、苏州、无锡和常州等地由于自身排放强度大而成为长三角一次污染最严重的地区,在以西北风为主的1月,浙北的嘉兴、湖州、杭州和绍兴等城市易受该地区污染南下传输影响;而在以偏南风为主的7月,该地区的污染物又会北上影响苏中的扬州、泰州和南通等城市.各城市一次污染来源分担结果显示,上海、南京、杭州等城市SO2、NOx和PM10的本地贡献率分别在61%、80%和76%以上;在1月,受外来影响较大的城市有舟山、镇江、嘉兴和绍兴,外来影响的总比例SO2、NOx和PM10分别在56%、40%和44%以上;在7月,舟山、南通、扬州、泰州和湖州受外来一次污染较大,SO2、NOx和PM10外来影响的总比例分别为66%、46%和53%以上.综合上述结果,目前长三角城市间一次污染跨界传输已十分显著,这也为区域二次污染的形成与加重提供了条件,区域尺度的大气污染协同控制显得十分必要和紧迫.

As one of the three largest economic hubs in China,the Yangtze River Delta （YRD） experiences serious air pollution due to the huge energy consumption and large emissions.In order to quantify the primary air pollution transport among cities in the YRD region,the Calpuff model,together with the regional emissions inventory of 15 cities and MM5 meteorological simulation,were applied to calculate the primary air pollution transport among cities in the YRD.Shanghai,Suzhou,Wuxi and Changzhou,which are all located along Taihu Lake,comprise the most severely polluted area in the region due to local emissions.In January,with the prevailing wind direction from the northwest,the cities of Jiaxing,Huzhou,Hangzhou and Shaoxing in northern Zhejiang province will be influenced by emissions from the northern cities.On the other hand,in July,with the prevailing wind direction from the south,the cities of Yangzhou,Taizhou and Nantong in central Jiangsu province will be affected by emissions from the southern cities.The results also show that local emissions are a major contributor to the primary pollution of a city,with SO2 61%,NOx 80% and PM10 76% in cities like Shanghai,Nanjing and Hangzhou.In January,cities with heavy influence of outside emissions include Zhoushan,Zhenjiang,Jiaxing and Shaoxing,with the total transport contribution rate of SO256%,NOx40% and PM1044%.In July,cities like Zhoushan,Nantong,Yangzhou,Taizhou and Huzhou will be greatly influenced by outside emissions,with the total external contribution rate of SO266%,NOx46% and PM1053%.In summary,the transboundary primary air pollution in the YRD is quite significant,which provides conditions for the formation and aggravation of the secondary air pollution.Synergistic control of air pollution at the regional scale is urgently needed.