江苏省徐州市近地层PM_(2.5)浓度时间变化特征及其与土地覆盖的关系

Temporal variation of PM_(2.5) concentration in the surface layer and its relationship with land cover in Xuzhou,Jiangsu

以徐州市代表性大气监测点为统计单元,研究其近地层PM_(2.5)浓度的时间变化特征,采用回归系数检验法分析PM_(2.5)浓度的差异特征.基于遥感影像获取土地覆盖信息,应用皮尔逊相关系数定量分析PM_(2.5)浓度与城市绿化率、河流水体占比、工业用地占比、主干道面积占比、建筑物占比、街道地形高宽比的相关程度.结果表明:PM_(2.5)浓度与河流水体占比呈负相关,与街道地形高宽比、工业用地占比、主干道面积占比和绿化率呈正相关.土地覆盖影响PM_(2.5)的扩散和形成;城市通风廊道有利于PM_(2.5)的扩散,街道峡谷效应明显;城市绿化有利于减弱PM_(2.5).

The representative air monitoring stations in Xuzhou are used as statistical units.Based on the method of regression coefficient test,the temporal variation of PM_（2.5）concentration in the surface layer are studied and the spatial distribution discrepancy are analyzed.By using the land cover information of remote sensing image,the correlation between PM_（2.5）concentration and the impact factors is quantitatively analyzed,including greening rate,river water body proportion,industrial land proportion,main road area proportion,building density and street terrain aspect ratio.The results show that the spatial distribution of PM_（2.5）is greatly influenced by the impact factors.In fact,the diffusion and the formation of PM_（2.5）are influenced by the types of the land cover.In addition,the ventilation corridors can deduce PM_（2.5）,and street and river can significantly influence the diffuseness and accumulation of PM_（2.5）.