Effect of urban form on PM2.5 concentrations in urban agglomerations of China: Insights from different urbanization levels and seasons

Genhong Gao; Steven G Pueppke; Qin Tao; Jing Wei; Weixin Ou; Yu Tao

doi:10.1016/j.jenvman.2022.116953

Effect of urban form on PM_2.5 concentrations in urban agglomerations of China: Insights from different urbanization levels and seasons

J Environ Manage. 2023 Feb 1:327:116953. doi: 10.1016/j.jenvman.2022.116953. Epub 2022 Dec 2.

Authors

Genhong Gao¹, Steven G Pueppke², Qin Tao³, Jing Wei⁴, Weixin Ou⁵, Yu Tao⁶

Affiliations

¹ College of Land Management, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: genhonggao@njau.edu.cn.
² Asia Hub, Nanjing Agricultural University, Nanjing 210095, China; Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI 48824, USA.
³ College of Land Management, Nanjing Agricultural University, Nanjing 210095, China.
⁴ State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, China; Department of Atmospheric and Oceanic Science, Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA.
⁵ College of Land Management, Nanjing Agricultural University, Nanjing 210095, China; National & Local Joint Engineering, Research Center for Rural Land Resources Use and Consolidation, Nanjing 210095, China. Electronic address: owx@njau.edu.cn.
⁶ College of Land Management, Nanjing Agricultural University, Nanjing 210095, China; National & Local Joint Engineering, Research Center for Rural Land Resources Use and Consolidation, Nanjing 210095, China. Electronic address: taoyu@njau.edu.cn.

PMID: 36470182
DOI: 10.1016/j.jenvman.2022.116953

Abstract

Planned urban form has become an important strategy to improve air quality in urban agglomerations (UAs), especially pollution due to PM_2.5, but the influencing mechanisms are not yet clear. This study explores the relationship between four metrics of urban form (size, fragmentation, shape, and dispersion) as determined by analysis of remotely sensed images at 30-m resolution and PM_2.5 concentrations in 19 Chinese UAs. The influence of level of urban development and season is examined. Five control variables, including population density, temperature, precipitation, wind speed, and the normalized difference vegetation index (NDVI) are selected for use in multiple linear regression models. Size, fragmentation, and shape of urban form, but not dispersion, were found to have significant effects on PM_2.5 concentrations of different urbanization-level UAs. Urban size and fragmentation have stronger impacts on PM_2.5 concentrations in UAs with lower urbanization levels while urban shape has a greater impact in higher-level UAs. In terms of seasonal variation in all UAs, urban form is more pronouncedly associated with PM_2.5 concentrations during spring and autumn than summer and winter. Urban size and fragmentation are positively associated with PM_2.5 concentrations whereas urban shape and dispersion are on the contrary. The relationships between urban form and PM_2.5 uncovered here underscore the importance of urban planning as a tool to minimize PM_2.5 pollution. Specifically, local government should encourage polycentric urban form with lower fragmentation in urban agglomerations. UAs with lower urbanization levels should control the disordered expansion of construction land and higher-level UAs should promote the mix of green land and construction land. Moreover, measures to control air pollution from anthropogenic activities in spring, autumn and winter are likely to be more effective in decreasing PM_2.5 concentrations in UAs.

Keywords: PM(2.5) concentrations; Seasons; Urban agglomerations; Urban form; Urbanization levels.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
China
Cities
Environmental Monitoring / methods
Particulate Matter / analysis
Seasons
Urbanization

Substances

Air Pollutants
Particulate Matter