Ecology and Environment ›› 2021, Vol. 30 ›› Issue (11): 2157-2164.DOI: 10.16258/j.cnki.1674-5906.2021.11.006

• Research Articles • Previous Articles     Next Articles

Spatio-temporal Distribution Characteristics of PM2.5 and Air Quality Evaluation in Urban Street Canyons: Take Changhuai Street in Hefei as An Example

WANG Wei1,2(), CHENG Xinyue1, HU Chun1,2, XIA Sihan1, WANG Tian1   

  1. 1. School of Architecture and Urban Planning, Anhui Jianzhu University, Hefei 230022, China
    2. Key Laboratory of Built Environment and Health, Anhui Jianzhu University, Hefei 230022, China
  • Received:2021-06-11 Online:2021-11-18 Published:2021-12-29

城市街道峡谷PM2.5时空分布特征与空气质量评价——以合肥市长淮街道为例

王薇1,2(), 程歆玥1, 胡春1,2, 夏斯涵1, 王甜1   

  1. 1.安徽建筑大学建筑与规划学院,安徽 合肥 230022
    2.安徽建筑大学建成环境与健康重点实验室,安徽 合肥 230022
  • 作者简介:王薇(1975年生),女,教授,博士,研究方向为建筑技术和人居环境。E-mail: vivi.gan@126.com
  • 基金资助:
    国家自然科学基金项目(51778001);国家重点研发计划(2017YFC0702503);安徽省教育厅高校优秀拔尖人才培育资助项目(gxbJZD23)

Abstract:

The air pollution represented by PM2.5 has a great impact on the life of urban residents. Street canyon is an important part of the city and one of the main places where urban residents live. In this study, PM2.5 was taken as the research object. From January 22 to January 24, 2021, seven fixed monitoring stations were set up in the street canyon of Changhuai Street, Yaohai District, Hefei City, and the pollution level of PM2.5 in the street canyon of Hefei City in winter and its influencing factors were analyzed with reference to the national control point of Sanli Street nearby. The results show that, (1) the average daily mass concentration of PM2.5 in street canyons presents a “W”-shaped variation. Non-essential commuters in street canyons should avoid traveling at noon peak on working days, and can choose to travel between 15:00 and 16:00. (2) The trend of PM2.5 concentration in different street canyons was: road intersection>roadside>community park green space>general street canyons. The larger the wind speed is, the farther it is from the emission pollution source and the closer it is to the greening plants, the lower the mass concentration of PM2.5. Park green space, wide street canyon, reducing the height of windward buildings and increasing street width can all reduce the PM2.5 concentration in street canyon. The leeward side of the rising street canyon is easy to cause the accumulation of PM2.5 with high mass concentration. (3) In winter, the air quality level of PM2.5 is moderate pollution, and the air quality level is Grade 4. The contribution of humidity to PM2.5 concentration in street canyons is greater than that of temperature, and the contribution of humidity and temperature to PM2.5 concentration in street canyons is 80.5% and 54.7%, respectively.

Key words: street canyon, PM2.5, temporal and spatial distribution, air quality evaluation, temperature and humidity, wind speed, traffic flow

摘要:

以PM2.5为代表的空气污染对城市居民的生活产生了巨大的影响。街道峡谷是城市的重要构成部分,是城市居民生活的主要场所之一。以PM2.5为研究对象,于2021年1月22—24日在合肥市瑶海区长淮街道的街道峡谷设立7个固定式监测点,并以附近的三里街国控点为参照,分析冬季合肥市街道峡谷的PM2.5污染水平及其影响因素。研究表明,(1)街道峡谷内PM2.5日均质量浓度呈现“W”型变化特征。在街道峡谷非必要通勤市民,应避免在工作日午高峰出行,可以选择在15:00—16:00出行。(2)不同街道峡谷内PM2.5质量浓度大小趋势为:道路交叉口>道路旁>小区公园绿地>一般街道峡谷。风速越大,距离排放污染源越远,距离绿化植物越近,PM2.5质量浓度越低。公园绿地、宽阔型街道峡谷、降低迎风面建筑高度和增加街道宽度都能降低街道峡谷内部的PM2.5质量浓度。上升型街道峡谷的背风侧易造成高质量浓度PM2.5累积。(3)对合肥市长淮街道冬季而言,PM2.5的空气质量水平为中度污染,空气质量级别为四级。湿度对街道峡谷的PM2.5质量浓度贡献度比温度更大,湿度和温度对街道峡谷的PM2.5质量浓度贡献度分别为80.5%和54.7%。

关键词: 街道峡谷, PM2.5, 时空分布, 空气质量评价, 温湿度, 风速, 车流量

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