基于MODIS数据的滁州市空气质量指数遥感监测研究

Research of the remote sensing monitoring of air quality index in Chuzhou city based on MODIS data

分别建立首要污染物为PM_(2.5)和臭氧时的AQI与MODIS 3 km AOD之间的关系模型,对滁州市空气质量指数分布进行遥感监测。结果表明,①首要污染物为PM_(2.5)时,进行气溶胶标高和湿度影响因子订正,引进具有显著相关的风速气象因子,并考虑风向这个定性因子,引入风向虚拟变量;首要污染物为臭氧时,引进具有显著相关的最高温度、气压,分别进行多元回归分析,拟合优度均较一元三次模型显著提高,建立本地空气质量指数遥感监测模型。②遥感监测拟合方程较好地显示了气象因子对空气质量指数的影响作用。首要污染物为PM_(2.5)时,风速对PM_(2.5)的扩散与传输起主导作用,AQI与风速大小成反比;偏NW风时,AQI较大,本地空气质量可能受上游污染物输送影响;偏SE风时,更容易出现AQI高值,偏SE方向的持续弱风更易导致污染物的持续累积。副热带高压持续控制下,形成持续的高温,低层为弱低压,易形成首要污染物为臭氧的污染,AQI与最高温度成正比、与气压成反比。③使用拟合方程,利用MODIS 3 km AOD反演AQI分布和每日变化分析2个遥感监测实例,具有地面监测不可比拟的优势。

The relational models are established respectivelybetween MODIS 3 km AOD and AQI,when the primary pollutant is PM_(2.5) or ozone to monitor the AQI of Chuzhou.The results show that,①When the primary pollutant is PM_(2.5),the vertical aerosol scale heights and humidity effect factors are taken into account,the wind speed meteorological factor having significant correlation with AQI and the wind direction dummy variables considering the qualitative factor of wind direction are introduced.When the primary pollutant is ozone,the maximum temperature and air pressure with significant correlation are introduced.After carrying out multivariate regres⁃sion analysis respectively,the goodness of fit is significantly higher than that of the cubic model,and the local air quality index remote sensing monitoring model is established.②The fitting equation of remote sensing monitoring well shows the influence of meteorological factors on air quality index.When the primary pollutant is PM_(2.5),wind speed is a dominant factor in the diffusion and transmission of air pollutants and the value of AQI is inversely proportional to the wind speed.Local air quality may be affected by upstream pollutant transport in northwester wind which will cause AQI to increase and a continuous weak wind in southeast direction will lead to continu⁃ous accumulation of pollutants which will lead to high values of AQI.It is easy to form the pollution of which the primary pollutant is ozone under the continuous control of the subtropical high,causing continuous high temperature with weak low pressure formed in low layer,and the value of AQI is proportional to the maximum temperature and inversely proportional to the pressure.③Using the fitting model,we use MODIS 3 km AOD to retrieve AQI distribution and daily variation of two cases,which has the incomparable advantage over ground monitoring.