长江三角洲城市群空气质量时空分布特征

基于数理统计、空间插值技术、相关性分析与GIS地图表达,研究长江三角洲城市群AQI及各空气含量因子污染浓度的时间、空间分布特征。通过提取国务院最新规划的长江三角洲城市群空间分布数据,划分研究区为"一核五圈",探讨了空气质量指数的时间变化特征和AQI、首要污染物的空间分布规律,定量评价了AQI与其污染因子的相关性,结果表明:(1)时间变化上,长三角城市群空气质量季均变化规律为夏季最好,冬季最差;月均变化呈波浪形分布,在1月份的平均浓度皆为最高;周均变化为:在一周后半段达到一周最大值;(2)空间分布上,分季节看,AQI在春、秋、冬三季空间梯度变化显著,呈现北高、南低的分布格局。在首要污染物的分布上,以PM_(2.5)和O_3均分长三角地区;(3)PM_(2.5)含量空间分布与AQI有较高相似性,均处于北高南低的分布状态,臭氧分布呈现东高西低,即较发达的城市臭氧含量相对较高的空间分布格局。最后通过相关性计算,AQI与PM_(2.5)相关性显著,与O_3没有明显相关性,为长三角大气污染防治提供依据。

SPATIAL-TEMPORAL DISTRIBUTION CHARACTERISTICS OF AIR QUALITY IN THE URBAN AGGLOMERATION OF THE YANGTZE RIVER DELTA

The spatial-temporal distribution characteristics of the concentrations of air pollution factor and AQI of urban agglomeration in Yangtze River Delta (YRD) were studied using spatial interpolation technique,correlation analysis and GIS.By extracting the spatial distribution data of urban agglomeration in the YRD according to the State Council's latest plan,the current study area were divided into'a core area and five metropolitan areas'.We analyzed temporal variation characteristics of AQI,spatial distribution of AQI and primary pollutants,and quantitatively evaluated the relationships between AQI and their influencing factors.The results showed that seasonal variation of air quality in the urban agglomeration in YRD was the best in summer and the worst in winter;the mean concentration of each month was the highest in January;AQI reached the maximum value in the second half of the week from the weeks mean change.The spatial gradient of AQI significantly changed in the spring,autumn and winter,showing a distribution pattern in which AQI was high in the north area and low in the south,while the AQI in summer had little change in the spatial gradient,and the spatial variation was not obvious.The primary pollutants in the Yangtze River Delta were PM2.5 and O3.The main pollutant in Shanghai and Ningbo metropolitan area was O3.The main pollutant in Su-Xi-Chang area and Hefei metropolitan area was PM2.5.The spatial distribution of PM2.5 in the 26 cities of the Yangtze River Delta city group was similar to that of AQI and the distribution of O3 was high in the east and low in the west in the YRD.From O3 spatial distribution,we can see that the relatively high level of ozone in the city is relatively high.Finally,by correlation calculation,significant correlation was found between AQI and PM2.5 and no significant correlation was found between O3 and AQI.These studies provided the basis for the prevention and control of atmospheric pollution in the YRD.