长江经济带PM_(2.5)时空特征及影响因素研究

大气细颗粒物(PM_(2.5))因其对空气环境质量乃至人类健康的巨大危害而逐渐引起学者们的关注。本文以我国综合实力最强、战略支撑作用最为突出的区域之一——长江经济带为研究对象,基于城市级空气质量监测数据,运用地理学时空分析与GIS可视化方法探索并呈现了2015年长江经济带PM_(2.5)的时空分布特征及其演变规律;在此基础上,结合空间回归模型考察了PM_(2.5)浓度与区域城市发展之间的内在关系。结果表明,就空间特征而言,长江中下游地区PM_(2.5)污染较长江上游地区更为严重,长江北岸地区比长江南岸地区更为严重;PM_(2.5)高浓度集聚地带主要位于鄂皖苏大部分地区,与空气质量较佳的云南及其周边地区呈"对角"分布状态。长江经济带内城市间PM_(2.5)浓度存在着显著的正向空间自相关,且自相关性随距离增大而不断减弱,其门槛尺度约为900 km;在这一范围内,PM_(2.5)空间集聚效应较为明显。就时间特征而言,冬季PM_(2.5)浓度相对较高,春秋两季次之,夏季空气质量最好;各地区浓度分布在年初相对离散,后有所趋同。此外,PM_(2.5)与其他类型的大气污染物(如SO2、NO2、O3)浓度两两之间均存在着显著的正相关性,暗示大气污染物从原发污染演变为二次污染,形成恶性循环。空间回归分析结果表明,PM_(2.5)污染随经济发展水平的提高呈现先上升后下降的趋势,在一定程度上支持了"环境库兹涅兹曲线"假说;且人口密度、公共交通运输强度均在不同程度上导致长江经济带PM_(2.5)浓度的升高。最后,从区域性联防联控、不同类型大气污染物协同治理、促进经济发展方式转型等方面为长江经济带的大气环境治理提出切实可行的政策建议。

Spatial-temporal characteristics of PM2.5and its influencing factors in the Yangtze River Economic Belt

Airborne fine particulate matter (PM2.5) has brought serious harm to atmospheric environment and human health thus incurring great concern of scholars.This article targets one of the most competitive and strategic areas of China,the Yangtze River Economic Belt,to conduct the research.Based on the air quality monitoring data on the city level,the paper discussed the spatialtemporal characteristics of the PM2.5 in the Yangtze River Economic Belt in 2015 by the geographical spatial analysis and GISvisualization method.Furthermore,a spatial regression was conducted to show the internal correlation between PM2.5 and regional social and economic development.The results showed that,in the aspect of spatial feature,the midstream and downstream area suffered more serious PM2.5 pollution than upstream area,while the north shore suffers more than the south shore.Precisely,most of areas of Hubei,Anhui and Jiangsu provinces were the hot spots of PM2.5 pollution,presenting a diagonal symmetry to Yunnan and its surrounding areas which have pretty clean air.PM2.5 concentration displayed a significantly positive spatial autocorrelation which decreased as the distance increased with a threshold scale of about 900km.Within this distance the spatial cluster was relatively significant.In the aspect of temporal feature,winter had the relatively highest PM2.5 concentration,followed by spring and autumn,while air quality in summer was the best.PM2.5 concentration distribution tends to be diverse in the beginning of the year but converge to some extent later.Besides,there's a pairwise correlation between PM2.5,SO2,NO2 and O3,which implied a transfer from primary pollution to secondary pollution leading to a vicious circle.Spatial regression indicated that PM2.5 pollution rised firstly but fell later as GDP per capita increased,which to some degree supports the hypothesis of'Environmental Kuznets Curve'.Besides,the increase of population density and public transportation intensity could also worsen the PM2.5 pollution.Finally,the article proposes a series of practical policies from the aspects of regional cooperating depollution,synergetic reduction of various air pollutants and the improvement of economic growth pattern.