Monitoring the Spatial Variation of Aerosol Optical Depth and Its Correlation with Land Use/Land Cover in Wuhan, China: A Perspective of Urban Planning.

Qijiao Xie,Qi Sun

doi:10.3390/ijerph18031132

Abstract

Aerosols significantly affect environmental conditions, air quality, and public health locally, regionally, and globally. Examining the impact of land use/land cover (LULC) on aerosol optical depth (AOD) helps to understand how human activities influence air quality and develop suitable solutions. The Landsat 8 image and Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products in summer in 2018 were used in LULC classification and AOD retrieval in this study. Spatial statistics and correlation analysis about the relationship between LULC and AOD were performed to examine the impact of LULC on AOD in summer in Wuhan, China. Results indicate that the AOD distribution expressed an obvious “basin effect” in urban development areas: higher AOD values concentrated in water bodies with lower terrain, which were surrounded by the high buildings or mountains with lower AOD values. The AOD values were negatively correlated with the vegetated areas while positively correlated to water bodies and construction lands. The impact of LULC on AOD varied with different contexts in all cases, showing a “context effect”. The regression correlations among the normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI), normalized difference water index (NDWI), and AOD in given landscape contexts were much stronger than those throughout the whole study area. These findings provide sound evidence for urban planning, land use management and air quality improvement.

Highlights

Aerosols are solid or liquid particles suspended in air with the size ranging from0.001 to 10 μm
1.31% of the Wuhan administrative region was covered by aerosol optical depth (AOD) value higher than 0.5
When masking the AOD pattern (Figure 2a) over the land use/land cover (LULC) map (Figure 3a), we found that the aerosol distribution did not always correspond to land use types

Summary

Introduction

They are often observed as smoke, dust, fog, or haze, which significantly affect climatic change, environment condition, and air quality at a local scale, and regional and global ones [1,2,3,4]. By absorbing or scattering incident electromagnetic radiation, aerosols have obvious radiative forcing effects on climate and environment [5,6]. Fine particles and PM2.5 , aerosols with aerodynamic diameters of less than 2.5 μm, can seriously endanger public health [9,10], due to the harm to the respiration and blood circulation system of inhabitants [11]. Aerosols are considered as one of the main air pollutants that affect air quality and jeopardize public health [13].

Methods

Results

Discussion

Conclusion