Analysis Of Haze Causes Based On Remote Sensing Technology And Backward Trajectory Mode

The pollution gas emitted from the combustion of biomass fuel has an important impact on the regional air quality.In recent years,haze events due to straw burning have become more frequent.The air pollutants emitted by it will not only affect the local air quality,but will also cause the deterioration of the air quality in the surrounding provinces and cities and the occurrence of haze pollution events after long-distance atmospheric transport and specific weather conditions.This paper comprehensively uses remote sensing technology,satellite remote sensing fire point extraction method,historical meteorological observation data,NCEP reanalysis data,and backward trajectory model to focus on the analysis of atmospheric pollutants produced by straw burning in Henan Province to reach Shijiazhuang City via Shijiazhuang City.The meteorological conditions of the city at that time analyzed how the meteorological elements caused the pollutants transmitted from long distances to form hazy weather.The contamination of straw incineration in Henan Province from October 6 to 12,2014 led to a detailed analysis of the haze events in Shijiazhuang City.The specific results show that:(1)The fire spots extracted by using remote sensing technology are not all straw burning points.In this paper,the ground fire point in Henan Province extracted from MOD 14 fire point data product and the spatial distribution information of arable land in Henan Province extracted from the imagery are superimposed.The fixed heat source and misjudgment point are eliminated,and the straw burning fire point is accurately extracted.(2)The atmospheric pollutants produced by straw burning fire points will lead to the deterioration of air quality,and can spread through long distances under certain meteorological conditions to provide air pollution sources for neighboring provinces and cities.Using remote sensing technology,MODIS fire point product data to extract ground fire spots in Henan Province,and then using remote sensing images to extract spatial distribution information of arable land in Henan Province,and to superimpose ground fire point information and arable land spatial distribution information vector to further extract straw burning fire spots,made into a straw burning fire thematic map.Using the extracted fire point data and contaminant transmission trajectories for inspection and calibration to verify the sources of contaminated pollutants,the results showed that one of the sources of pollutants that caused the smog weather in Shijiazhuang City this time was caused by straw burning of air pollutants in Henan Province.(3)The fine particulate matter produced by straw burning in Henan Province is transported to the Jing-Jin-Ji area under the action of the southerly wind.When it reaches Shijiazhuang,the relative humidity is relatively high,with an average of more than 70%under a specific meteorological background;The distribution of field pressure and a relatively stable upper-air situation;the lower height of the mixed layer is not conducive to the timely diffusion of pollutants,which is the main cause of smog pollution in Shijiazhuang City.