| 引用本文: | 肖钟湧,林晓凤,陈坰烽,陈颖锋,谢静晗,李飒,施益强.2024.粤港澳大湾区甲醛污染的时空特征研究[J].地球环境学报,15(5):760-769 |
| XIAO Zhongyong,LIN Xiaofeng,CHEN Jiongfeng,CHEN Yingfeng,XIE Jinghan,LI Sa,SHI Yiqiang.2024.Temporal and spatial characteristics of HCHO pollution over Guangdong-Hong Kong-Macao Greater Bay Area, China[J].Journal of Earth Environment,15(5):760-769 |
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| 粤港澳大湾区甲醛污染的时空特征研究 |
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肖钟湧，林晓凤，陈坰烽，陈颖锋，谢静晗，李飒，施益强*
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集美大学 港口与海岸工程学院，集美大学地理国情监测研究中心，厦门 361021
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| 摘要: |
| 利用Aura卫星搭载的臭氧观测仪（ozone monitoring instrument，OMI）反演的甲醛（HCHO）柱密度数据，分析自2005年以来粤港澳大湾区（Guangdong-Hong Kong-Macao Greater Bay Area，GBA）HCHO的空间分布特征、变化趋势及其影响因素。研究结果表明HCHO呈现明显的增长趋势，2005年和2019年区域年平均分别为1.4840 mol·cm−2和1.7983 mol·cm−2，2005—2019年增长了0.3143 mol·cm−2，约为21.17%。粤港澳大湾区HCHO演化过程存在11个月的主振荡周期。HCHO月变化在时空上呈现明显差异，最大值和最小值分别出现在7月和1月，多年平均值分别为1.9824 mol·cm−2和1.1728 mol·cm−2。6月空间异质性最为明显，最大值和最小值分别为2.6842 mol·cm−2和1.0849 mol·cm−2。粤港澳大湾区HCHO污染严重的区域主要出现在中部，如中山市、佛山市和广州市，多年平均值高达1.9938 mol·cm−2。低值区主要在区域四周，特别是在惠州市，多年平均值约为1.3522 mol·cm−2。HCHO增长率在空间上呈现明显差异，增长量的变化范围为−0.1374—0.6833 mol·cm−2，增长率为−7.20%—52.53%。大部分区域的HCHO呈增长趋势，而在广州市部分地区出现减少，最大的减少量为−1.3742 mol·cm−2，约为−7.20%。从城市尺度来看，所有城市的HCHO均出现增长，增长量和增长率最大的是惠州市，分别为0.3863 mol·cm−2和28.27%；其次是江门市，分别为0.3411 mol·cm−2和23.71%；最小的是香港，分别为0.9093 mol·cm−2和6.52%。 |
| 关键词: 粤港澳大湾区 臭氧观测仪 甲醛 卫星遥感 变异系数 |
| DOI：10.7515/JEE222087 |
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| 基金项目:集美大学国家基金培育计划（ZP2021019）；福建省自然科学基金项目（2022J01817） |
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| Temporal and spatial characteristics of HCHO pollution over Guangdong-Hong Kong-Macao Greater Bay Area, China |
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XIAO Zhongyong, LIN Xiaofeng, CHEN Jiongfeng, CHEN Yingfeng, XIE Jinghan, LI Sa, SHI Yiqiang*
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National Geographic Conditions Monitoring Research Center, College of Harbour and Coastal Engineering, Jimei University, Xiamen 361021, China
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| Abstract: |
| Background, aim, and scope Formaldehyde (HCHO), a colorless and irritating trace chemical in the atmosphere, has a significant impact on human health, and human activity emissions are an important factor affecting the characteristics of atmospheric HCHO. One of China’s most economically developed regions, the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) is one of the most heavily polluted regions by HCHO attributable to human activities such industrial production emissions. We analyzed the spatial-temporal dynamics characteristics and their driving factors of HCHO in GBA from 2005 to 2019 using observations derived from ozone monitoring instrument (OMI) on the Aura satellite, which provides reference and theoretical support for the HCHO pollution control over the GBA. Materials and methods Satellite remote sensing technology has become an important means to study atmospheric HCHO pollution. The HCHO data used in this study were from the OMI sensor onboard the Aura satellite, which has an uncertainty of roughly 25%. The temporal span of the data was from January 2005 to December 2019, and the spatial resolution was 13 km×24 km. The data were synthesized at various time scales (monthly and yearly) and then interpolated using the nearest neighbor method to generate raster data. The average of the multi-year data at various time scales was computed for the purpose of simplifying data processing and analysis and reducing the uncertainty introduced by data noise. The spatial distribution characteristics were then examined using the results. The temporal variability characteristics of HCHO were represented by the regional monthly average values. The properties of the periodic variation at various scale levels were analyzed using the wavelet transform coefficients. The spatial and temporal coefficients of variation reflect the spatial heterogeneity and temporal fluctuations, respectively. Results The results revealed a notable upward trend in HCHO, which increased by 0.3143 mol·cm−2 (21.17%) from 2005 to 2019 over GBA. The time series of HCHO showed obvious periodic characteristics, with an 11-month main oscillation period in which the values of HCHO concentration were higher in summer and lower in winter. Due to the effects of anthropogenic emissions and various natural factors, the monthly HCHO variation over GBA was significantly different in time and space. The maximum and minimum values appeared in July and January, with multi-year monthly averages of 1.9824 mol·cm−2 and 1.1728 mol·cm−2, respectively. Spatial heterogeneity was most obvious in June, when the maximum and minimum values in space were 2.6842 mol·cm−2 and 1.0849 mol·cm−2, respectively. The high-value areas with serious HCHO pollution over GBA were mainly in the central regions, such as the cities of Zhongshan, Foshan, and Guangzhou. In these areas, the maximum multi-year average value can reach 1.9938 mol·cm−2. Low values were mainly in the surrounding region of GBA, especially in Huizhou. The minimum multi-year mean value was about 1.3522 mol·cm−2. Furthermore, the growth rate showed a significant difference among different regions, ranging from −7.20% to 52.53%. In most areas, HCHO displayed a positive growth trend, but it decreased in some areas of Guangzhou. The largest decrease was −1.3742 mol·cm−2 (about 7.20%). At the urban scale, HCHO increased across all cities. The most significant increase of 0.3863 mol·cm−2 (28.27%) occurred in Huizhou, followed by Jiangmen, which had an increase of 0.3411 mol·cm−2 (23.71%), and Hong Kong, with the smallest increase of 0.9093 mol·cm−2 (6.52%). Discussion The primary cause of the long-term, steady increase in HCHO was the increase in anthropogenic emissions, which include emissions from traffic and industry. Seasonal anthropogenic emissions, variations in surface vegetation cover, atmospheric chemical processes, and climatic circumstances all contribute to the regional heterogeneity and seasonal variability of atmospheric HCHO. For instance, during the summer plant development phase, the isoprene released by plants produces a significant amount of HCHO by photooxidation. Formaldehyde is also produced from nitrogen oxides, volatile organic compounds (VOCs), and other contaminants through atmospheric photochemical reactions that involve solar radiation. Consequently, the generation of HCHO decreases in tandem with reductions of temperature and sunlight. A large amount of precipitation promotes plant growth, which increases the production of VOCs during the plant growth process. These VOCs are then converted into formaldehyde. In addition, with the transformation of the economic structure, the emission sources of HCHO from industries have decreased. Conclusions Anthropogenic emissions have led to a significant increase of HCHO over the GBA, but the changes in industrial structure and the development of emerging industries have resulted in a decline of HCHO in urban aeras. The factors of meteorological conditions (temperature and precipitation), atmospheric chemical processes, differences in surface vegetation cover, and seasonal anthropogenic emissions, which have resulted in the seasonal variation characteristics of lower concentration in winter and high in summer of HCHO at the atmosphere. And the spatial heterogeneity of distribution that is the high-value areas with serious HCHO pollution over GBA were mainly in the central regions, low values were mainly in the surrounding region of GBA. Recommendations and perspectives The variation characteristics of HCHO in the atmosphere are influenced by various factors. The temporal and spatial variations of HCHO concentration over the GBA can thus be thoroughly analyzed by taking into account the meteorological conditions, topography, atmospheric chemical processes, variations in surface vegetation cover, and seasonal anthropogenic emissions. Moreover, a solid scientific foundation can be provided for HCHO pollution control over the GBA. |
| Key words: Guangdong-Hong Kong-Macao Greater Bay Area (GBA) OMI HCHO satellite remote sensing coefficient of variation |
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