甘肃省植被与对流层甲醛关系及影响因素分析

植被可以截获和吸收大气中的颗粒物、SO₂和NO_x等，对大气污染物具有一定净化作用，但也释放大量挥发性有机物，对光化学烟雾污染的形成具有促进作用.以甘肃省为例，利用卫星资料反演手段，解译了2008-2016年NDVI（植被覆盖指数）和对流层HCHO（甲醛）柱浓度，并探讨了二者之间的关系及影响因素.结果表明:①甘肃省2008-2016年NDVI空间分布梯度呈东南向西北递减的趋势，其年际动态不显著，季节性动态显著，与对流层HCHO柱浓度时空分布及动态有一定的相似性.②甘肃省对流层HCHO柱浓度和NDVI的年变化范围分别为7×1015~11×1015 molec/cm2和0.22~0.25，并且二者之间呈显著正相关，相关系数为0.63.③甘肃省NDVI和对流层HCHO柱浓度的分布与气象因素（如辐射、气温和降水量）有关，并且甘肃省中部对流层HCHO柱浓度分布还与甘肃省人类足迹分布特征相似.研究显示:甘肃省中部人类足迹指数高，HCHO主要来源于人类活动；而甘肃省西部和南部人类足迹指数低，HCHO主要来源于自然排放. 

Relationship between NDVI and Troposphere HCHO in Gansu Province and Its Influencing Factors

Vegetation can intercept and absorb particulate matter, sulfur dioxide and nitrogen oxides in the atmosphere, which plays a role in the purification of atmospheric pollution. However, it releases a large number of volatile organic compounds, which can promote the formation of photochemical smog pollution. Taking Gansu Province as an example, vegetation cover index (NDVI) and tropospheric formaldehyde (HCHO) column concentrations from 2008 to 2016 were interpreted by means of satellite data inversion, and the relationship between them and the influencing factors were discussed. The results show that:(1) The spatial distribution gradient of the NDVI in Gansu Province decreases from southeast to northwest from 2008 to 2016. The interannual dynamics are not significant but the seasonal dynamics are significant, which are similar to the temporal-spatial distribution and dynamics of HCHO column concentration. (2) The annual NDVI value varies from 0.22 to 0.25, while the HCHO column value ranges from 7×10¹⁵ to 11×10¹⁵ molec/cm², respectively, there is a significant positive correlation between them, and the correlation coefficient is 0.63. (3) The distribution of NDVI and HCHO in Gansu Province is not only related to meteorological factors such as radiation, temperature and precipitation, but also similar to the distribution characteristics of human footprint in the central part of Gansu Province. Researches have shown that the human footprint index in Central Gansu Province is high, HCHO is mainly derived from human activities, while the human footprint index in western and southern Gansu Province is low, and HCHO is mainly derived from natural emissions.