近三年中国甲醛时空分布特征及影响因素分析

近年来,研究大气污染物的时空分布特征及影响因素分析已成为环境科学领域研究的热点问题.本文基于OMI甲醛垂直柱浓度数据产品,结合各省市气象、植被、人类活动等数据,对全国2015—2017年甲醛柱浓度时空分布特征及影响因素进行了研究.结果表明,全国甲醛柱浓度分布极不均衡,整体呈现自东南沿海向西北递减的趋势,此外在新疆与西藏的小部分地区存在高值区域.3年来全国甲醛柱浓度为整体上升,且变化率在-1.02～1.46之间,其中全国81%地区呈上升趋势,19%地区呈下降趋势.全国甲醛柱浓度季节性变化规律表现为夏季春季秋季冬季.甲醛柱浓度时空分布受气象因素影响,整体上与气温、降水呈正相关,但部分地区降水对甲醛有消减作用;甲醛柱浓度也与植被量呈正相关,如植被丰富的西藏地区及我国东南部,植被对甲醛柱浓度的影响显著.全国大多数省份甲醛柱量与地区生产总值、汽车保有量呈显著正相关,人类足迹分布模式与甲醛柱浓度空间分布的一致性较高,指示在城市发达地区,人类活动和经济发展、汽车尾气是导致甲醛柱浓度增高的主要原因.

Temporal and spatial distribution characteristics and influencing factors of formaldehyde in China in recent three years

In recent years, it has become a hot issue in the field of environmental science to study the spatial and temporal distribution characteristics of atmospheric pollutants and their influencing factors. Based on OMI formaldehyde vertical column concentration data products, combined with the data of meteorology, vegetation and human activities in various provinces and cities, this paper studies the spatial and temporal distribution characteristics and influencing factors of formaldehyde column concentration in China from 2015 to 2017. The results show that the distribution of formaldehyde column concentration in the country is extremely uneven, and the overall trend is decreasing from the southeast coast to the northwest. In addition, there are high-value areas in a small part of Xinjiang and Tibet. The concentration of formaldehyde in the whole country shows an overall upward trend, and the rate of change is between 1.02 and 1.46. Among which, the formaldehyde column concentration in 81% of the areas shows an upward trend, while that in 19% of the areas shows a downward trend. The seasonal variation of the concentration of formaldehyde in the country is as follows:summer, spring, autumn, winter. The spatial and temporal distribution of formaldehyde concentration is affected by meteorological factors, and it is positively correlated with temperature and precipitation. However, precipitation in some areas has a depletion effect on formaldehyde. The concentration of formaldehyde column is also positively correlated with vegetation. For example, vegetation has a significant effect on the concentration of formaldehyde column in vegetation-rich Tibet and southeastern China. The amount of formaldehyde column in most Provinces of China shows a significant positive correlation with regional GDP and vehicle holdings. The distribution pattern of human footprint and the spatial distribution of formaldehyde column concentration are highly consistent. It shows that in urban developed areas, human activities, economic development, and automobile exhaust are the main reasons for the increase of formaldehyde column concentration.