Spatial And Temporal Distribution And Influencing Factors Of Formaldehyde In Western China Based On Satellite Remote Sensing

As one of the many trace gases in the atmosphere,formaldehyde plays an important role in the chemical reaction of the atmosphere,and is also one of the first carcinogens identified by the WHO.The Ozone Monitoring Instrument(OMI)on earth observation satellite(Aura)is used to invert trace gases in the atmosphere by introducing high resolution spectroscopy,which provides an important basis for the study of Earth climate change and atmospheric environment.In 2006,the state adopted the western development plan,which made the western region’s economy develop rapidly in recent years,and the pollutants in the atmosphere increased.This article takes the western region(except Inner Mongolia area)as the research object,through the HDF-View,VB programming and Arcgis software to deal with the OMHCHO products,get the monthly average of the vertical density of the formaldehyde in the western region.Using the monthly mean value of the concentration of formaldehyde column from January 2008 to December 2016,the spatial and temporal distribution characteristics and variation trend of the concentration of formaldehyde column in western regions and provinces and municipalities directly under the central government were analyzed.In addition,the MODIS-NDVI data of the western region of January 2008,January 2008-2016,was obtained by combining the data of the time series of the January 2008-2016,the monthly mean of the temperature and the precipitation in the western region of January 2008.The monthly mean and human footprint index data were used to analyze the relationship between the vegetation index,the atmospheric temperature,the precipitation,the human activity and the spatial and temporal distribution of the concentration of formaldehyde column.At the same time,the monthly mean change of the concentration of the formaldehyde column was studied in 11 municipalities directly under the central government of the western regions.The monthly mean change trend and monthly growth rate are simulated through the linear sine model of monthly mean,and the accuracy of change trend is evaluated.The study found that the study found that in the 2008-2016 years,the concentration of formaldehyde column in the western region showed a growing trend and a certain seasonal variation,among which the highest formaldehyde year was in2013 and the lowest in 2008.In the seasonal change,the concentration of formaldehyde column was the highest in spring and summer,and the concentration of formaldehyde column in the two seasons of autumn and winter was more than that of autumn and winter.Low.In the region,the concentration of formaldehyde column shows high concentration of formaldehyde column in the East,Southeast,northwest of Xinjiang and other areas with dense population and high level of economic development.The comparison of the concentration of formaldehyde column between the provinces and municipalities directly under the central government showed that all provinces and municipalities directly under the central government showed an overall trend of increase in the study time.The maximum concentration of formaldehyde column in the provinces and municipalities directly under the central government was different.The concentration of formaldehyde column in the southeastern provinces of Guangxi,Guizhou and Yunnan provinces was larger in spring,and Gansu Province,Chongqing city and Qinghai Province.The concentration of formaldehyde column in summer is higher in other provinces such as Hai and other provinces.The other provinces are generally low in spring,summer and the same season,and autumn and winter in the two seasons.The vegetation index(NDVI),the mean temperature monthly mean,the monthly mean of precipitation and the human footprint were selected in the analysis of the influencing factors.It was found that the vegetation index had great influence on the eastern and southern regions of the study area.The correlation of temperature to the concentration of formaldehyde column was generally positive,and the rainfall in the western region of the study area was small.The elimination effect of aldehyde is not obvious in the eastern region.In the comparison of the spatial distribution of the human footprint and the spatial distribution of the concentration of the formaldehyde column,it is found that the spatial distribution of the concentration value of the formaldehyde column in the western region is very similar to the distribution of the human footprint,and the concentration of the formaldehyde column in the western region is closely related to the human activity.