成都市PM_(2.5)浓度时空变化特征及影响因子分析

近年来,空气质量问题日渐突出,大气污染已严重影响了人们的身体健康和日常生活。为了探究成都市近年来的大气污染状况,分析大气颗粒物浓度的时空变化特征及其控制性因子,本文利用2016年成都市逐小时PM_(2.5)监测数据,分析成都市PM_(2.5)浓度时空变化特征,探索气象因子与城市空间形态因子(建筑错落度)对PM_(2.5)浓度变化的影响。结果表明:(1)成都市PM_(2.5)浓度的日变化特征表现为城市中心具有"单峰单谷"特征,而城市郊区日变化特征不明显。且城市中心PM_(2.5)浓度空间变化特征整体表现为由西北向东南逐渐减小的趋势。(2)从全年来看,成都市PM_(2.5)浓度与气温和风速均呈显著负相关,与海平面气压呈显著正相关,而与相对湿度的相关性不明显。(3)PM_(2.5)浓度日间变化率与城市空间形态因子的相关性较强,建筑错落度越高,PM_(2.5)浓度下降越快。

An Analysis of Temporal and Spatial Variation of PM2.5 Concentration and Influencing Factors in Chengdu

In recent years, air pollution has seriously affected people's health and daily life, and has become a research hotspot. In order to explore the air pollution situation in Chengdu in 2016, analyzethe temporal and spatial variation characteristics of atmospheric particulate matter concentration and its control factors. In this article, the hourly PM2.5 monitoring data of Chengdu in 2016 were used to analyze the temporal and spatial variation of PM2.5 concentration, and to explore the influence of meteorological factors and urban spatial morphology factors (building otherness) on PM2.5 concentration. The results showed that: ①the diurnal variation of PM2.5 concentration showed the characteristic of "single peak and single valley" in urban center, however, but not obvious in suburban area. The average daily variation of PM2.5 concentration was intense in autumn and winter, while stable in spring and summer. The spatial variation of PM2.5 was decreasing from northwest to southeast. ②Annual average of PM2.5 concentration was significantly negatively correlated with temperature and wind speed, and positively correlated with sea level pressure, but not with the relative humidity. ③The diurnal variation rate of PM2.5 concentration has a strong correlation with the urban spatial morphology factor, the higher the building otherness, the faster PM2.5 concentration spread.